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author | hiddenpath <hiddenpath@yandex-team.com> | 2024-04-02 23:50:23 +0300 |
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committer | hiddenpath <hiddenpath@yandex-team.com> | 2024-04-03 00:02:31 +0300 |
commit | 8923c6d2c438e0aeed2e06b8b0275e1864eeee33 (patch) | |
tree | 6b5e476699fc0be5091cb650654ef5f602c8afff /contrib/go/_std_1.22/src/fmt | |
parent | d18afd09df2a08cd023012593b46109b77713a6c (diff) | |
download | ydb-8923c6d2c438e0aeed2e06b8b0275e1864eeee33.tar.gz |
Update golang to 1.22.1
2967d19c907adf59101a1f47b4208bd0b04a6186
Diffstat (limited to 'contrib/go/_std_1.22/src/fmt')
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/doc.go | 384 | ||||
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/errors.go | 78 | ||||
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/format.go | 594 | ||||
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/print.go | 1224 | ||||
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/scan.go | 1238 | ||||
-rw-r--r-- | contrib/go/_std_1.22/src/fmt/ya.make | 11 |
6 files changed, 3529 insertions, 0 deletions
diff --git a/contrib/go/_std_1.22/src/fmt/doc.go b/contrib/go/_std_1.22/src/fmt/doc.go new file mode 100644 index 0000000000..1cda484d8a --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/doc.go @@ -0,0 +1,384 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package fmt implements formatted I/O with functions analogous +to C's printf and scanf. The format 'verbs' are derived from C's but +are simpler. + +# Printing + +The verbs: + +General: + + %v the value in a default format + when printing structs, the plus flag (%+v) adds field names + %#v a Go-syntax representation of the value + %T a Go-syntax representation of the type of the value + %% a literal percent sign; consumes no value + +Boolean: + + %t the word true or false + +Integer: + + %b base 2 + %c the character represented by the corresponding Unicode code point + %d base 10 + %o base 8 + %O base 8 with 0o prefix + %q a single-quoted character literal safely escaped with Go syntax. + %x base 16, with lower-case letters for a-f + %X base 16, with upper-case letters for A-F + %U Unicode format: U+1234; same as "U+%04X" + +Floating-point and complex constituents: + + %b decimalless scientific notation with exponent a power of two, + in the manner of strconv.FormatFloat with the 'b' format, + e.g. -123456p-78 + %e scientific notation, e.g. -1.234456e+78 + %E scientific notation, e.g. -1.234456E+78 + %f decimal point but no exponent, e.g. 123.456 + %F synonym for %f + %g %e for large exponents, %f otherwise. Precision is discussed below. + %G %E for large exponents, %F otherwise + %x hexadecimal notation (with decimal power of two exponent), e.g. -0x1.23abcp+20 + %X upper-case hexadecimal notation, e.g. -0X1.23ABCP+20 + +String and slice of bytes (treated equivalently with these verbs): + + %s the uninterpreted bytes of the string or slice + %q a double-quoted string safely escaped with Go syntax + %x base 16, lower-case, two characters per byte + %X base 16, upper-case, two characters per byte + +Slice: + + %p address of 0th element in base 16 notation, with leading 0x + +Pointer: + + %p base 16 notation, with leading 0x + The %b, %d, %o, %x and %X verbs also work with pointers, + formatting the value exactly as if it were an integer. + +The default format for %v is: + + bool: %t + int, int8 etc.: %d + uint, uint8 etc.: %d, %#x if printed with %#v + float32, complex64, etc: %g + string: %s + chan: %p + pointer: %p + +For compound objects, the elements are printed using these rules, recursively, +laid out like this: + + struct: {field0 field1 ...} + array, slice: [elem0 elem1 ...] + maps: map[key1:value1 key2:value2 ...] + pointer to above: &{}, &[], &map[] + +Width is specified by an optional decimal number immediately preceding the verb. +If absent, the width is whatever is necessary to represent the value. +Precision is specified after the (optional) width by a period followed by a +decimal number. If no period is present, a default precision is used. +A period with no following number specifies a precision of zero. +Examples: + + %f default width, default precision + %9f width 9, default precision + %.2f default width, precision 2 + %9.2f width 9, precision 2 + %9.f width 9, precision 0 + +Width and precision are measured in units of Unicode code points, +that is, runes. (This differs from C's printf where the +units are always measured in bytes.) Either or both of the flags +may be replaced with the character '*', causing their values to be +obtained from the next operand (preceding the one to format), +which must be of type int. + +For most values, width is the minimum number of runes to output, +padding the formatted form with spaces if necessary. + +For strings, byte slices and byte arrays, however, precision +limits the length of the input to be formatted (not the size of +the output), truncating if necessary. Normally it is measured in +runes, but for these types when formatted with the %x or %X format +it is measured in bytes. + +For floating-point values, width sets the minimum width of the field and +precision sets the number of places after the decimal, if appropriate, +except that for %g/%G precision sets the maximum number of significant +digits (trailing zeros are removed). For example, given 12.345 the format +%6.3f prints 12.345 while %.3g prints 12.3. The default precision for %e, %f +and %#g is 6; for %g it is the smallest number of digits necessary to identify +the value uniquely. + +For complex numbers, the width and precision apply to the two +components independently and the result is parenthesized, so %f applied +to 1.2+3.4i produces (1.200000+3.400000i). + +When formatting a single integer code point or a rune string (type []rune) +with %q, invalid Unicode code points are changed to the Unicode replacement +character, U+FFFD, as in strconv.QuoteRune. + +Other flags: + + '+' always print a sign for numeric values; + guarantee ASCII-only output for %q (%+q) + '-' pad with spaces on the right rather than the left (left-justify the field) + '#' alternate format: add leading 0b for binary (%#b), 0 for octal (%#o), + 0x or 0X for hex (%#x or %#X); suppress 0x for %p (%#p); + for %q, print a raw (backquoted) string if strconv.CanBackquote + returns true; + always print a decimal point for %e, %E, %f, %F, %g and %G; + do not remove trailing zeros for %g and %G; + write e.g. U+0078 'x' if the character is printable for %U (%#U). + ' ' (space) leave a space for elided sign in numbers (% d); + put spaces between bytes printing strings or slices in hex (% x, % X) + '0' pad with leading zeros rather than spaces; + for numbers, this moves the padding after the sign; + ignored for strings, byte slices and byte arrays + +Flags are ignored by verbs that do not expect them. +For example there is no alternate decimal format, so %#d and %d +behave identically. + +For each Printf-like function, there is also a Print function +that takes no format and is equivalent to saying %v for every +operand. Another variant Println inserts blanks between +operands and appends a newline. + +Regardless of the verb, if an operand is an interface value, +the internal concrete value is used, not the interface itself. +Thus: + + var i interface{} = 23 + fmt.Printf("%v\n", i) + +will print 23. + +Except when printed using the verbs %T and %p, special +formatting considerations apply for operands that implement +certain interfaces. In order of application: + +1. If the operand is a reflect.Value, the operand is replaced by the +concrete value that it holds, and printing continues with the next rule. + +2. If an operand implements the Formatter interface, it will +be invoked. In this case the interpretation of verbs and flags is +controlled by that implementation. + +3. If the %v verb is used with the # flag (%#v) and the operand +implements the GoStringer interface, that will be invoked. + +If the format (which is implicitly %v for Println etc.) is valid +for a string (%s %q %x %X), or is %v but not %#v, +the following two rules apply: + +4. If an operand implements the error interface, the Error method +will be invoked to convert the object to a string, which will then +be formatted as required by the verb (if any). + +5. If an operand implements method String() string, that method +will be invoked to convert the object to a string, which will then +be formatted as required by the verb (if any). + +For compound operands such as slices and structs, the format +applies to the elements of each operand, recursively, not to the +operand as a whole. Thus %q will quote each element of a slice +of strings, and %6.2f will control formatting for each element +of a floating-point array. + +However, when printing a byte slice with a string-like verb +(%s %q %x %X), it is treated identically to a string, as a single item. + +To avoid recursion in cases such as + + type X string + func (x X) String() string { return Sprintf("<%s>", x) } + +convert the value before recurring: + + func (x X) String() string { return Sprintf("<%s>", string(x)) } + +Infinite recursion can also be triggered by self-referential data +structures, such as a slice that contains itself as an element, if +that type has a String method. Such pathologies are rare, however, +and the package does not protect against them. + +When printing a struct, fmt cannot and therefore does not invoke +formatting methods such as Error or String on unexported fields. + +# Explicit argument indexes + +In Printf, Sprintf, and Fprintf, the default behavior is for each +formatting verb to format successive arguments passed in the call. +However, the notation [n] immediately before the verb indicates that the +nth one-indexed argument is to be formatted instead. The same notation +before a '*' for a width or precision selects the argument index holding +the value. After processing a bracketed expression [n], subsequent verbs +will use arguments n+1, n+2, etc. unless otherwise directed. + +For example, + + fmt.Sprintf("%[2]d %[1]d\n", 11, 22) + +will yield "22 11", while + + fmt.Sprintf("%[3]*.[2]*[1]f", 12.0, 2, 6) + +equivalent to + + fmt.Sprintf("%6.2f", 12.0) + +will yield " 12.00". Because an explicit index affects subsequent verbs, +this notation can be used to print the same values multiple times +by resetting the index for the first argument to be repeated: + + fmt.Sprintf("%d %d %#[1]x %#x", 16, 17) + +will yield "16 17 0x10 0x11". + +# Format errors + +If an invalid argument is given for a verb, such as providing +a string to %d, the generated string will contain a +description of the problem, as in these examples: + + Wrong type or unknown verb: %!verb(type=value) + Printf("%d", "hi"): %!d(string=hi) + Too many arguments: %!(EXTRA type=value) + Printf("hi", "guys"): hi%!(EXTRA string=guys) + Too few arguments: %!verb(MISSING) + Printf("hi%d"): hi%!d(MISSING) + Non-int for width or precision: %!(BADWIDTH) or %!(BADPREC) + Printf("%*s", 4.5, "hi"): %!(BADWIDTH)hi + Printf("%.*s", 4.5, "hi"): %!(BADPREC)hi + Invalid or invalid use of argument index: %!(BADINDEX) + Printf("%*[2]d", 7): %!d(BADINDEX) + Printf("%.[2]d", 7): %!d(BADINDEX) + +All errors begin with the string "%!" followed sometimes +by a single character (the verb) and end with a parenthesized +description. + +If an Error or String method triggers a panic when called by a +print routine, the fmt package reformats the error message +from the panic, decorating it with an indication that it came +through the fmt package. For example, if a String method +calls panic("bad"), the resulting formatted message will look +like + + %!s(PANIC=bad) + +The %!s just shows the print verb in use when the failure +occurred. If the panic is caused by a nil receiver to an Error +or String method, however, the output is the undecorated +string, "<nil>". + +# Scanning + +An analogous set of functions scans formatted text to yield +values. Scan, Scanf and Scanln read from os.Stdin; Fscan, +Fscanf and Fscanln read from a specified io.Reader; Sscan, +Sscanf and Sscanln read from an argument string. + +Scan, Fscan, Sscan treat newlines in the input as spaces. + +Scanln, Fscanln and Sscanln stop scanning at a newline and +require that the items be followed by a newline or EOF. + +Scanf, Fscanf, and Sscanf parse the arguments according to a +format string, analogous to that of Printf. In the text that +follows, 'space' means any Unicode whitespace character +except newline. + +In the format string, a verb introduced by the % character +consumes and parses input; these verbs are described in more +detail below. A character other than %, space, or newline in +the format consumes exactly that input character, which must +be present. A newline with zero or more spaces before it in +the format string consumes zero or more spaces in the input +followed by a single newline or the end of the input. A space +following a newline in the format string consumes zero or more +spaces in the input. Otherwise, any run of one or more spaces +in the format string consumes as many spaces as possible in +the input. Unless the run of spaces in the format string +appears adjacent to a newline, the run must consume at least +one space from the input or find the end of the input. + +The handling of spaces and newlines differs from that of C's +scanf family: in C, newlines are treated as any other space, +and it is never an error when a run of spaces in the format +string finds no spaces to consume in the input. + +The verbs behave analogously to those of Printf. +For example, %x will scan an integer as a hexadecimal number, +and %v will scan the default representation format for the value. +The Printf verbs %p and %T and the flags # and + are not implemented. +For floating-point and complex values, all valid formatting verbs +(%b %e %E %f %F %g %G %x %X and %v) are equivalent and accept +both decimal and hexadecimal notation (for example: "2.3e+7", "0x4.5p-8") +and digit-separating underscores (for example: "3.14159_26535_89793"). + +Input processed by verbs is implicitly space-delimited: the +implementation of every verb except %c starts by discarding +leading spaces from the remaining input, and the %s verb +(and %v reading into a string) stops consuming input at the first +space or newline character. + +The familiar base-setting prefixes 0b (binary), 0o and 0 (octal), +and 0x (hexadecimal) are accepted when scanning integers +without a format or with the %v verb, as are digit-separating +underscores. + +Width is interpreted in the input text but there is no +syntax for scanning with a precision (no %5.2f, just %5f). +If width is provided, it applies after leading spaces are +trimmed and specifies the maximum number of runes to read +to satisfy the verb. For example, + + Sscanf(" 1234567 ", "%5s%d", &s, &i) + +will set s to "12345" and i to 67 while + + Sscanf(" 12 34 567 ", "%5s%d", &s, &i) + +will set s to "12" and i to 34. + +In all the scanning functions, a carriage return followed +immediately by a newline is treated as a plain newline +(\r\n means the same as \n). + +In all the scanning functions, if an operand implements method +Scan (that is, it implements the Scanner interface) that +method will be used to scan the text for that operand. Also, +if the number of arguments scanned is less than the number of +arguments provided, an error is returned. + +All arguments to be scanned must be either pointers to basic +types or implementations of the Scanner interface. + +Like Scanf and Fscanf, Sscanf need not consume its entire input. +There is no way to recover how much of the input string Sscanf used. + +Note: Fscan etc. can read one character (rune) past the input +they return, which means that a loop calling a scan routine +may skip some of the input. This is usually a problem only +when there is no space between input values. If the reader +provided to Fscan implements ReadRune, that method will be used +to read characters. If the reader also implements UnreadRune, +that method will be used to save the character and successive +calls will not lose data. To attach ReadRune and UnreadRune +methods to a reader without that capability, use +bufio.NewReader. +*/ +package fmt diff --git a/contrib/go/_std_1.22/src/fmt/errors.go b/contrib/go/_std_1.22/src/fmt/errors.go new file mode 100644 index 0000000000..1fbd39f8f1 --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/errors.go @@ -0,0 +1,78 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package fmt + +import ( + "errors" + "sort" +) + +// Errorf formats according to a format specifier and returns the string as a +// value that satisfies error. +// +// If the format specifier includes a %w verb with an error operand, +// the returned error will implement an Unwrap method returning the operand. +// If there is more than one %w verb, the returned error will implement an +// Unwrap method returning a []error containing all the %w operands in the +// order they appear in the arguments. +// It is invalid to supply the %w verb with an operand that does not implement +// the error interface. The %w verb is otherwise a synonym for %v. +func Errorf(format string, a ...any) error { + p := newPrinter() + p.wrapErrs = true + p.doPrintf(format, a) + s := string(p.buf) + var err error + switch len(p.wrappedErrs) { + case 0: + err = errors.New(s) + case 1: + w := &wrapError{msg: s} + w.err, _ = a[p.wrappedErrs[0]].(error) + err = w + default: + if p.reordered { + sort.Ints(p.wrappedErrs) + } + var errs []error + for i, argNum := range p.wrappedErrs { + if i > 0 && p.wrappedErrs[i-1] == argNum { + continue + } + if e, ok := a[argNum].(error); ok { + errs = append(errs, e) + } + } + err = &wrapErrors{s, errs} + } + p.free() + return err +} + +type wrapError struct { + msg string + err error +} + +func (e *wrapError) Error() string { + return e.msg +} + +func (e *wrapError) Unwrap() error { + return e.err +} + +type wrapErrors struct { + msg string + errs []error +} + +func (e *wrapErrors) Error() string { + return e.msg +} + +func (e *wrapErrors) Unwrap() []error { + return e.errs +} diff --git a/contrib/go/_std_1.22/src/fmt/format.go b/contrib/go/_std_1.22/src/fmt/format.go new file mode 100644 index 0000000000..617f78f15e --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/format.go @@ -0,0 +1,594 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package fmt + +import ( + "strconv" + "unicode/utf8" +) + +const ( + ldigits = "0123456789abcdefx" + udigits = "0123456789ABCDEFX" +) + +const ( + signed = true + unsigned = false +) + +// flags placed in a separate struct for easy clearing. +type fmtFlags struct { + widPresent bool + precPresent bool + minus bool + plus bool + sharp bool + space bool + zero bool + + // For the formats %+v %#v, we set the plusV/sharpV flags + // and clear the plus/sharp flags since %+v and %#v are in effect + // different, flagless formats set at the top level. + plusV bool + sharpV bool +} + +// A fmt is the raw formatter used by Printf etc. +// It prints into a buffer that must be set up separately. +type fmt struct { + buf *buffer + + fmtFlags + + wid int // width + prec int // precision + + // intbuf is large enough to store %b of an int64 with a sign and + // avoids padding at the end of the struct on 32 bit architectures. + intbuf [68]byte +} + +func (f *fmt) clearflags() { + f.fmtFlags = fmtFlags{} +} + +func (f *fmt) init(buf *buffer) { + f.buf = buf + f.clearflags() +} + +// writePadding generates n bytes of padding. +func (f *fmt) writePadding(n int) { + if n <= 0 { // No padding bytes needed. + return + } + buf := *f.buf + oldLen := len(buf) + newLen := oldLen + n + // Make enough room for padding. + if newLen > cap(buf) { + buf = make(buffer, cap(buf)*2+n) + copy(buf, *f.buf) + } + // Decide which byte the padding should be filled with. + padByte := byte(' ') + if f.zero { + padByte = byte('0') + } + // Fill padding with padByte. + padding := buf[oldLen:newLen] + for i := range padding { + padding[i] = padByte + } + *f.buf = buf[:newLen] +} + +// pad appends b to f.buf, padded on left (!f.minus) or right (f.minus). +func (f *fmt) pad(b []byte) { + if !f.widPresent || f.wid == 0 { + f.buf.write(b) + return + } + width := f.wid - utf8.RuneCount(b) + if !f.minus { + // left padding + f.writePadding(width) + f.buf.write(b) + } else { + // right padding + f.buf.write(b) + f.writePadding(width) + } +} + +// padString appends s to f.buf, padded on left (!f.minus) or right (f.minus). +func (f *fmt) padString(s string) { + if !f.widPresent || f.wid == 0 { + f.buf.writeString(s) + return + } + width := f.wid - utf8.RuneCountInString(s) + if !f.minus { + // left padding + f.writePadding(width) + f.buf.writeString(s) + } else { + // right padding + f.buf.writeString(s) + f.writePadding(width) + } +} + +// fmtBoolean formats a boolean. +func (f *fmt) fmtBoolean(v bool) { + if v { + f.padString("true") + } else { + f.padString("false") + } +} + +// fmtUnicode formats a uint64 as "U+0078" or with f.sharp set as "U+0078 'x'". +func (f *fmt) fmtUnicode(u uint64) { + buf := f.intbuf[0:] + + // With default precision set the maximum needed buf length is 18 + // for formatting -1 with %#U ("U+FFFFFFFFFFFFFFFF") which fits + // into the already allocated intbuf with a capacity of 68 bytes. + prec := 4 + if f.precPresent && f.prec > 4 { + prec = f.prec + // Compute space needed for "U+" , number, " '", character, "'". + width := 2 + prec + 2 + utf8.UTFMax + 1 + if width > len(buf) { + buf = make([]byte, width) + } + } + + // Format into buf, ending at buf[i]. Formatting numbers is easier right-to-left. + i := len(buf) + + // For %#U we want to add a space and a quoted character at the end of the buffer. + if f.sharp && u <= utf8.MaxRune && strconv.IsPrint(rune(u)) { + i-- + buf[i] = '\'' + i -= utf8.RuneLen(rune(u)) + utf8.EncodeRune(buf[i:], rune(u)) + i-- + buf[i] = '\'' + i-- + buf[i] = ' ' + } + // Format the Unicode code point u as a hexadecimal number. + for u >= 16 { + i-- + buf[i] = udigits[u&0xF] + prec-- + u >>= 4 + } + i-- + buf[i] = udigits[u] + prec-- + // Add zeros in front of the number until requested precision is reached. + for prec > 0 { + i-- + buf[i] = '0' + prec-- + } + // Add a leading "U+". + i-- + buf[i] = '+' + i-- + buf[i] = 'U' + + oldZero := f.zero + f.zero = false + f.pad(buf[i:]) + f.zero = oldZero +} + +// fmtInteger formats signed and unsigned integers. +func (f *fmt) fmtInteger(u uint64, base int, isSigned bool, verb rune, digits string) { + negative := isSigned && int64(u) < 0 + if negative { + u = -u + } + + buf := f.intbuf[0:] + // The already allocated f.intbuf with a capacity of 68 bytes + // is large enough for integer formatting when no precision or width is set. + if f.widPresent || f.precPresent { + // Account 3 extra bytes for possible addition of a sign and "0x". + width := 3 + f.wid + f.prec // wid and prec are always positive. + if width > len(buf) { + // We're going to need a bigger boat. + buf = make([]byte, width) + } + } + + // Two ways to ask for extra leading zero digits: %.3d or %03d. + // If both are specified the f.zero flag is ignored and + // padding with spaces is used instead. + prec := 0 + if f.precPresent { + prec = f.prec + // Precision of 0 and value of 0 means "print nothing" but padding. + if prec == 0 && u == 0 { + oldZero := f.zero + f.zero = false + f.writePadding(f.wid) + f.zero = oldZero + return + } + } else if f.zero && f.widPresent { + prec = f.wid + if negative || f.plus || f.space { + prec-- // leave room for sign + } + } + + // Because printing is easier right-to-left: format u into buf, ending at buf[i]. + // We could make things marginally faster by splitting the 32-bit case out + // into a separate block but it's not worth the duplication, so u has 64 bits. + i := len(buf) + // Use constants for the division and modulo for more efficient code. + // Switch cases ordered by popularity. + switch base { + case 10: + for u >= 10 { + i-- + next := u / 10 + buf[i] = byte('0' + u - next*10) + u = next + } + case 16: + for u >= 16 { + i-- + buf[i] = digits[u&0xF] + u >>= 4 + } + case 8: + for u >= 8 { + i-- + buf[i] = byte('0' + u&7) + u >>= 3 + } + case 2: + for u >= 2 { + i-- + buf[i] = byte('0' + u&1) + u >>= 1 + } + default: + panic("fmt: unknown base; can't happen") + } + i-- + buf[i] = digits[u] + for i > 0 && prec > len(buf)-i { + i-- + buf[i] = '0' + } + + // Various prefixes: 0x, -, etc. + if f.sharp { + switch base { + case 2: + // Add a leading 0b. + i-- + buf[i] = 'b' + i-- + buf[i] = '0' + case 8: + if buf[i] != '0' { + i-- + buf[i] = '0' + } + case 16: + // Add a leading 0x or 0X. + i-- + buf[i] = digits[16] + i-- + buf[i] = '0' + } + } + if verb == 'O' { + i-- + buf[i] = 'o' + i-- + buf[i] = '0' + } + + if negative { + i-- + buf[i] = '-' + } else if f.plus { + i-- + buf[i] = '+' + } else if f.space { + i-- + buf[i] = ' ' + } + + // Left padding with zeros has already been handled like precision earlier + // or the f.zero flag is ignored due to an explicitly set precision. + oldZero := f.zero + f.zero = false + f.pad(buf[i:]) + f.zero = oldZero +} + +// truncateString truncates the string s to the specified precision, if present. +func (f *fmt) truncateString(s string) string { + if f.precPresent { + n := f.prec + for i := range s { + n-- + if n < 0 { + return s[:i] + } + } + } + return s +} + +// truncate truncates the byte slice b as a string of the specified precision, if present. +func (f *fmt) truncate(b []byte) []byte { + if f.precPresent { + n := f.prec + for i := 0; i < len(b); { + n-- + if n < 0 { + return b[:i] + } + wid := 1 + if b[i] >= utf8.RuneSelf { + _, wid = utf8.DecodeRune(b[i:]) + } + i += wid + } + } + return b +} + +// fmtS formats a string. +func (f *fmt) fmtS(s string) { + s = f.truncateString(s) + f.padString(s) +} + +// fmtBs formats the byte slice b as if it was formatted as string with fmtS. +func (f *fmt) fmtBs(b []byte) { + b = f.truncate(b) + f.pad(b) +} + +// fmtSbx formats a string or byte slice as a hexadecimal encoding of its bytes. +func (f *fmt) fmtSbx(s string, b []byte, digits string) { + length := len(b) + if b == nil { + // No byte slice present. Assume string s should be encoded. + length = len(s) + } + // Set length to not process more bytes than the precision demands. + if f.precPresent && f.prec < length { + length = f.prec + } + // Compute width of the encoding taking into account the f.sharp and f.space flag. + width := 2 * length + if width > 0 { + if f.space { + // Each element encoded by two hexadecimals will get a leading 0x or 0X. + if f.sharp { + width *= 2 + } + // Elements will be separated by a space. + width += length - 1 + } else if f.sharp { + // Only a leading 0x or 0X will be added for the whole string. + width += 2 + } + } else { // The byte slice or string that should be encoded is empty. + if f.widPresent { + f.writePadding(f.wid) + } + return + } + // Handle padding to the left. + if f.widPresent && f.wid > width && !f.minus { + f.writePadding(f.wid - width) + } + // Write the encoding directly into the output buffer. + buf := *f.buf + if f.sharp { + // Add leading 0x or 0X. + buf = append(buf, '0', digits[16]) + } + var c byte + for i := 0; i < length; i++ { + if f.space && i > 0 { + // Separate elements with a space. + buf = append(buf, ' ') + if f.sharp { + // Add leading 0x or 0X for each element. + buf = append(buf, '0', digits[16]) + } + } + if b != nil { + c = b[i] // Take a byte from the input byte slice. + } else { + c = s[i] // Take a byte from the input string. + } + // Encode each byte as two hexadecimal digits. + buf = append(buf, digits[c>>4], digits[c&0xF]) + } + *f.buf = buf + // Handle padding to the right. + if f.widPresent && f.wid > width && f.minus { + f.writePadding(f.wid - width) + } +} + +// fmtSx formats a string as a hexadecimal encoding of its bytes. +func (f *fmt) fmtSx(s, digits string) { + f.fmtSbx(s, nil, digits) +} + +// fmtBx formats a byte slice as a hexadecimal encoding of its bytes. +func (f *fmt) fmtBx(b []byte, digits string) { + f.fmtSbx("", b, digits) +} + +// fmtQ formats a string as a double-quoted, escaped Go string constant. +// If f.sharp is set a raw (backquoted) string may be returned instead +// if the string does not contain any control characters other than tab. +func (f *fmt) fmtQ(s string) { + s = f.truncateString(s) + if f.sharp && strconv.CanBackquote(s) { + f.padString("`" + s + "`") + return + } + buf := f.intbuf[:0] + if f.plus { + f.pad(strconv.AppendQuoteToASCII(buf, s)) + } else { + f.pad(strconv.AppendQuote(buf, s)) + } +} + +// fmtC formats an integer as a Unicode character. +// If the character is not valid Unicode, it will print '\ufffd'. +func (f *fmt) fmtC(c uint64) { + // Explicitly check whether c exceeds utf8.MaxRune since the conversion + // of a uint64 to a rune may lose precision that indicates an overflow. + r := rune(c) + if c > utf8.MaxRune { + r = utf8.RuneError + } + buf := f.intbuf[:0] + f.pad(utf8.AppendRune(buf, r)) +} + +// fmtQc formats an integer as a single-quoted, escaped Go character constant. +// If the character is not valid Unicode, it will print '\ufffd'. +func (f *fmt) fmtQc(c uint64) { + r := rune(c) + if c > utf8.MaxRune { + r = utf8.RuneError + } + buf := f.intbuf[:0] + if f.plus { + f.pad(strconv.AppendQuoteRuneToASCII(buf, r)) + } else { + f.pad(strconv.AppendQuoteRune(buf, r)) + } +} + +// fmtFloat formats a float64. It assumes that verb is a valid format specifier +// for strconv.AppendFloat and therefore fits into a byte. +func (f *fmt) fmtFloat(v float64, size int, verb rune, prec int) { + // Explicit precision in format specifier overrules default precision. + if f.precPresent { + prec = f.prec + } + // Format number, reserving space for leading + sign if needed. + num := strconv.AppendFloat(f.intbuf[:1], v, byte(verb), prec, size) + if num[1] == '-' || num[1] == '+' { + num = num[1:] + } else { + num[0] = '+' + } + // f.space means to add a leading space instead of a "+" sign unless + // the sign is explicitly asked for by f.plus. + if f.space && num[0] == '+' && !f.plus { + num[0] = ' ' + } + // Special handling for infinities and NaN, + // which don't look like a number so shouldn't be padded with zeros. + if num[1] == 'I' || num[1] == 'N' { + oldZero := f.zero + f.zero = false + // Remove sign before NaN if not asked for. + if num[1] == 'N' && !f.space && !f.plus { + num = num[1:] + } + f.pad(num) + f.zero = oldZero + return + } + // The sharp flag forces printing a decimal point for non-binary formats + // and retains trailing zeros, which we may need to restore. + if f.sharp && verb != 'b' { + digits := 0 + switch verb { + case 'v', 'g', 'G', 'x': + digits = prec + // If no precision is set explicitly use a precision of 6. + if digits == -1 { + digits = 6 + } + } + + // Buffer pre-allocated with enough room for + // exponent notations of the form "e+123" or "p-1023". + var tailBuf [6]byte + tail := tailBuf[:0] + + hasDecimalPoint := false + sawNonzeroDigit := false + // Starting from i = 1 to skip sign at num[0]. + for i := 1; i < len(num); i++ { + switch num[i] { + case '.': + hasDecimalPoint = true + case 'p', 'P': + tail = append(tail, num[i:]...) + num = num[:i] + case 'e', 'E': + if verb != 'x' && verb != 'X' { + tail = append(tail, num[i:]...) + num = num[:i] + break + } + fallthrough + default: + if num[i] != '0' { + sawNonzeroDigit = true + } + // Count significant digits after the first non-zero digit. + if sawNonzeroDigit { + digits-- + } + } + } + if !hasDecimalPoint { + // Leading digit 0 should contribute once to digits. + if len(num) == 2 && num[1] == '0' { + digits-- + } + num = append(num, '.') + } + for digits > 0 { + num = append(num, '0') + digits-- + } + num = append(num, tail...) + } + // We want a sign if asked for and if the sign is not positive. + if f.plus || num[0] != '+' { + // If we're zero padding to the left we want the sign before the leading zeros. + // Achieve this by writing the sign out and then padding the unsigned number. + if f.zero && f.widPresent && f.wid > len(num) { + f.buf.writeByte(num[0]) + f.writePadding(f.wid - len(num)) + f.buf.write(num[1:]) + return + } + f.pad(num) + return + } + // No sign to show and the number is positive; just print the unsigned number. + f.pad(num[1:]) +} diff --git a/contrib/go/_std_1.22/src/fmt/print.go b/contrib/go/_std_1.22/src/fmt/print.go new file mode 100644 index 0000000000..cb393bd763 --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/print.go @@ -0,0 +1,1224 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package fmt + +import ( + "internal/fmtsort" + "io" + "os" + "reflect" + "strconv" + "sync" + "unicode/utf8" +) + +// Strings for use with buffer.WriteString. +// This is less overhead than using buffer.Write with byte arrays. +const ( + commaSpaceString = ", " + nilAngleString = "<nil>" + nilParenString = "(nil)" + nilString = "nil" + mapString = "map[" + percentBangString = "%!" + missingString = "(MISSING)" + badIndexString = "(BADINDEX)" + panicString = "(PANIC=" + extraString = "%!(EXTRA " + badWidthString = "%!(BADWIDTH)" + badPrecString = "%!(BADPREC)" + noVerbString = "%!(NOVERB)" + invReflectString = "<invalid reflect.Value>" +) + +// State represents the printer state passed to custom formatters. +// It provides access to the io.Writer interface plus information about +// the flags and options for the operand's format specifier. +type State interface { + // Write is the function to call to emit formatted output to be printed. + Write(b []byte) (n int, err error) + // Width returns the value of the width option and whether it has been set. + Width() (wid int, ok bool) + // Precision returns the value of the precision option and whether it has been set. + Precision() (prec int, ok bool) + + // Flag reports whether the flag c, a character, has been set. + Flag(c int) bool +} + +// Formatter is implemented by any value that has a Format method. +// The implementation controls how State and rune are interpreted, +// and may call Sprint() or Fprint(f) etc. to generate its output. +type Formatter interface { + Format(f State, verb rune) +} + +// Stringer is implemented by any value that has a String method, +// which defines the “native” format for that value. +// The String method is used to print values passed as an operand +// to any format that accepts a string or to an unformatted printer +// such as Print. +type Stringer interface { + String() string +} + +// GoStringer is implemented by any value that has a GoString method, +// which defines the Go syntax for that value. +// The GoString method is used to print values passed as an operand +// to a %#v format. +type GoStringer interface { + GoString() string +} + +// FormatString returns a string representing the fully qualified formatting +// directive captured by the State, followed by the argument verb. (State does not +// itself contain the verb.) The result has a leading percent sign followed by any +// flags, the width, and the precision. Missing flags, width, and precision are +// omitted. This function allows a Formatter to reconstruct the original +// directive triggering the call to Format. +func FormatString(state State, verb rune) string { + var tmp [16]byte // Use a local buffer. + b := append(tmp[:0], '%') + for _, c := range " +-#0" { // All known flags + if state.Flag(int(c)) { // The argument is an int for historical reasons. + b = append(b, byte(c)) + } + } + if w, ok := state.Width(); ok { + b = strconv.AppendInt(b, int64(w), 10) + } + if p, ok := state.Precision(); ok { + b = append(b, '.') + b = strconv.AppendInt(b, int64(p), 10) + } + b = utf8.AppendRune(b, verb) + return string(b) +} + +// Use simple []byte instead of bytes.Buffer to avoid large dependency. +type buffer []byte + +func (b *buffer) write(p []byte) { + *b = append(*b, p...) +} + +func (b *buffer) writeString(s string) { + *b = append(*b, s...) +} + +func (b *buffer) writeByte(c byte) { + *b = append(*b, c) +} + +func (b *buffer) writeRune(r rune) { + *b = utf8.AppendRune(*b, r) +} + +// pp is used to store a printer's state and is reused with sync.Pool to avoid allocations. +type pp struct { + buf buffer + + // arg holds the current item, as an interface{}. + arg any + + // value is used instead of arg for reflect values. + value reflect.Value + + // fmt is used to format basic items such as integers or strings. + fmt fmt + + // reordered records whether the format string used argument reordering. + reordered bool + // goodArgNum records whether the most recent reordering directive was valid. + goodArgNum bool + // panicking is set by catchPanic to avoid infinite panic, recover, panic, ... recursion. + panicking bool + // erroring is set when printing an error string to guard against calling handleMethods. + erroring bool + // wrapErrs is set when the format string may contain a %w verb. + wrapErrs bool + // wrappedErrs records the targets of the %w verb. + wrappedErrs []int +} + +var ppFree = sync.Pool{ + New: func() any { return new(pp) }, +} + +// newPrinter allocates a new pp struct or grabs a cached one. +func newPrinter() *pp { + p := ppFree.Get().(*pp) + p.panicking = false + p.erroring = false + p.wrapErrs = false + p.fmt.init(&p.buf) + return p +} + +// free saves used pp structs in ppFree; avoids an allocation per invocation. +func (p *pp) free() { + // Proper usage of a sync.Pool requires each entry to have approximately + // the same memory cost. To obtain this property when the stored type + // contains a variably-sized buffer, we add a hard limit on the maximum + // buffer to place back in the pool. If the buffer is larger than the + // limit, we drop the buffer and recycle just the printer. + // + // See https://golang.org/issue/23199. + if cap(p.buf) > 64*1024 { + p.buf = nil + } else { + p.buf = p.buf[:0] + } + if cap(p.wrappedErrs) > 8 { + p.wrappedErrs = nil + } + + p.arg = nil + p.value = reflect.Value{} + p.wrappedErrs = p.wrappedErrs[:0] + ppFree.Put(p) +} + +func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent } + +func (p *pp) Precision() (prec int, ok bool) { return p.fmt.prec, p.fmt.precPresent } + +func (p *pp) Flag(b int) bool { + switch b { + case '-': + return p.fmt.minus + case '+': + return p.fmt.plus || p.fmt.plusV + case '#': + return p.fmt.sharp || p.fmt.sharpV + case ' ': + return p.fmt.space + case '0': + return p.fmt.zero + } + return false +} + +// Implement Write so we can call Fprintf on a pp (through State), for +// recursive use in custom verbs. +func (p *pp) Write(b []byte) (ret int, err error) { + p.buf.write(b) + return len(b), nil +} + +// Implement WriteString so that we can call io.WriteString +// on a pp (through state), for efficiency. +func (p *pp) WriteString(s string) (ret int, err error) { + p.buf.writeString(s) + return len(s), nil +} + +// These routines end in 'f' and take a format string. + +// Fprintf formats according to a format specifier and writes to w. +// It returns the number of bytes written and any write error encountered. +func Fprintf(w io.Writer, format string, a ...any) (n int, err error) { + p := newPrinter() + p.doPrintf(format, a) + n, err = w.Write(p.buf) + p.free() + return +} + +// Printf formats according to a format specifier and writes to standard output. +// It returns the number of bytes written and any write error encountered. +func Printf(format string, a ...any) (n int, err error) { + return Fprintf(os.Stdout, format, a...) +} + +// Sprintf formats according to a format specifier and returns the resulting string. +func Sprintf(format string, a ...any) string { + p := newPrinter() + p.doPrintf(format, a) + s := string(p.buf) + p.free() + return s +} + +// Appendf formats according to a format specifier, appends the result to the byte +// slice, and returns the updated slice. +func Appendf(b []byte, format string, a ...any) []byte { + p := newPrinter() + p.doPrintf(format, a) + b = append(b, p.buf...) + p.free() + return b +} + +// These routines do not take a format string + +// Fprint formats using the default formats for its operands and writes to w. +// Spaces are added between operands when neither is a string. +// It returns the number of bytes written and any write error encountered. +func Fprint(w io.Writer, a ...any) (n int, err error) { + p := newPrinter() + p.doPrint(a) + n, err = w.Write(p.buf) + p.free() + return +} + +// Print formats using the default formats for its operands and writes to standard output. +// Spaces are added between operands when neither is a string. +// It returns the number of bytes written and any write error encountered. +func Print(a ...any) (n int, err error) { + return Fprint(os.Stdout, a...) +} + +// Sprint formats using the default formats for its operands and returns the resulting string. +// Spaces are added between operands when neither is a string. +func Sprint(a ...any) string { + p := newPrinter() + p.doPrint(a) + s := string(p.buf) + p.free() + return s +} + +// Append formats using the default formats for its operands, appends the result to +// the byte slice, and returns the updated slice. +func Append(b []byte, a ...any) []byte { + p := newPrinter() + p.doPrint(a) + b = append(b, p.buf...) + p.free() + return b +} + +// These routines end in 'ln', do not take a format string, +// always add spaces between operands, and add a newline +// after the last operand. + +// Fprintln formats using the default formats for its operands and writes to w. +// Spaces are always added between operands and a newline is appended. +// It returns the number of bytes written and any write error encountered. +func Fprintln(w io.Writer, a ...any) (n int, err error) { + p := newPrinter() + p.doPrintln(a) + n, err = w.Write(p.buf) + p.free() + return +} + +// Println formats using the default formats for its operands and writes to standard output. +// Spaces are always added between operands and a newline is appended. +// It returns the number of bytes written and any write error encountered. +func Println(a ...any) (n int, err error) { + return Fprintln(os.Stdout, a...) +} + +// Sprintln formats using the default formats for its operands and returns the resulting string. +// Spaces are always added between operands and a newline is appended. +func Sprintln(a ...any) string { + p := newPrinter() + p.doPrintln(a) + s := string(p.buf) + p.free() + return s +} + +// Appendln formats using the default formats for its operands, appends the result +// to the byte slice, and returns the updated slice. Spaces are always added +// between operands and a newline is appended. +func Appendln(b []byte, a ...any) []byte { + p := newPrinter() + p.doPrintln(a) + b = append(b, p.buf...) + p.free() + return b +} + +// getField gets the i'th field of the struct value. +// If the field itself is a non-nil interface, return a value for +// the thing inside the interface, not the interface itself. +func getField(v reflect.Value, i int) reflect.Value { + val := v.Field(i) + if val.Kind() == reflect.Interface && !val.IsNil() { + val = val.Elem() + } + return val +} + +// tooLarge reports whether the magnitude of the integer is +// too large to be used as a formatting width or precision. +func tooLarge(x int) bool { + const max int = 1e6 + return x > max || x < -max +} + +// parsenum converts ASCII to integer. num is 0 (and isnum is false) if no number present. +func parsenum(s string, start, end int) (num int, isnum bool, newi int) { + if start >= end { + return 0, false, end + } + for newi = start; newi < end && '0' <= s[newi] && s[newi] <= '9'; newi++ { + if tooLarge(num) { + return 0, false, end // Overflow; crazy long number most likely. + } + num = num*10 + int(s[newi]-'0') + isnum = true + } + return +} + +func (p *pp) unknownType(v reflect.Value) { + if !v.IsValid() { + p.buf.writeString(nilAngleString) + return + } + p.buf.writeByte('?') + p.buf.writeString(v.Type().String()) + p.buf.writeByte('?') +} + +func (p *pp) badVerb(verb rune) { + p.erroring = true + p.buf.writeString(percentBangString) + p.buf.writeRune(verb) + p.buf.writeByte('(') + switch { + case p.arg != nil: + p.buf.writeString(reflect.TypeOf(p.arg).String()) + p.buf.writeByte('=') + p.printArg(p.arg, 'v') + case p.value.IsValid(): + p.buf.writeString(p.value.Type().String()) + p.buf.writeByte('=') + p.printValue(p.value, 'v', 0) + default: + p.buf.writeString(nilAngleString) + } + p.buf.writeByte(')') + p.erroring = false +} + +func (p *pp) fmtBool(v bool, verb rune) { + switch verb { + case 't', 'v': + p.fmt.fmtBoolean(v) + default: + p.badVerb(verb) + } +} + +// fmt0x64 formats a uint64 in hexadecimal and prefixes it with 0x or +// not, as requested, by temporarily setting the sharp flag. +func (p *pp) fmt0x64(v uint64, leading0x bool) { + sharp := p.fmt.sharp + p.fmt.sharp = leading0x + p.fmt.fmtInteger(v, 16, unsigned, 'v', ldigits) + p.fmt.sharp = sharp +} + +// fmtInteger formats a signed or unsigned integer. +func (p *pp) fmtInteger(v uint64, isSigned bool, verb rune) { + switch verb { + case 'v': + if p.fmt.sharpV && !isSigned { + p.fmt0x64(v, true) + } else { + p.fmt.fmtInteger(v, 10, isSigned, verb, ldigits) + } + case 'd': + p.fmt.fmtInteger(v, 10, isSigned, verb, ldigits) + case 'b': + p.fmt.fmtInteger(v, 2, isSigned, verb, ldigits) + case 'o', 'O': + p.fmt.fmtInteger(v, 8, isSigned, verb, ldigits) + case 'x': + p.fmt.fmtInteger(v, 16, isSigned, verb, ldigits) + case 'X': + p.fmt.fmtInteger(v, 16, isSigned, verb, udigits) + case 'c': + p.fmt.fmtC(v) + case 'q': + p.fmt.fmtQc(v) + case 'U': + p.fmt.fmtUnicode(v) + default: + p.badVerb(verb) + } +} + +// fmtFloat formats a float. The default precision for each verb +// is specified as last argument in the call to fmt_float. +func (p *pp) fmtFloat(v float64, size int, verb rune) { + switch verb { + case 'v': + p.fmt.fmtFloat(v, size, 'g', -1) + case 'b', 'g', 'G', 'x', 'X': + p.fmt.fmtFloat(v, size, verb, -1) + case 'f', 'e', 'E': + p.fmt.fmtFloat(v, size, verb, 6) + case 'F': + p.fmt.fmtFloat(v, size, 'f', 6) + default: + p.badVerb(verb) + } +} + +// fmtComplex formats a complex number v with +// r = real(v) and j = imag(v) as (r+ji) using +// fmtFloat for r and j formatting. +func (p *pp) fmtComplex(v complex128, size int, verb rune) { + // Make sure any unsupported verbs are found before the + // calls to fmtFloat to not generate an incorrect error string. + switch verb { + case 'v', 'b', 'g', 'G', 'x', 'X', 'f', 'F', 'e', 'E': + oldPlus := p.fmt.plus + p.buf.writeByte('(') + p.fmtFloat(real(v), size/2, verb) + // Imaginary part always has a sign. + p.fmt.plus = true + p.fmtFloat(imag(v), size/2, verb) + p.buf.writeString("i)") + p.fmt.plus = oldPlus + default: + p.badVerb(verb) + } +} + +func (p *pp) fmtString(v string, verb rune) { + switch verb { + case 'v': + if p.fmt.sharpV { + p.fmt.fmtQ(v) + } else { + p.fmt.fmtS(v) + } + case 's': + p.fmt.fmtS(v) + case 'x': + p.fmt.fmtSx(v, ldigits) + case 'X': + p.fmt.fmtSx(v, udigits) + case 'q': + p.fmt.fmtQ(v) + default: + p.badVerb(verb) + } +} + +func (p *pp) fmtBytes(v []byte, verb rune, typeString string) { + switch verb { + case 'v', 'd': + if p.fmt.sharpV { + p.buf.writeString(typeString) + if v == nil { + p.buf.writeString(nilParenString) + return + } + p.buf.writeByte('{') + for i, c := range v { + if i > 0 { + p.buf.writeString(commaSpaceString) + } + p.fmt0x64(uint64(c), true) + } + p.buf.writeByte('}') + } else { + p.buf.writeByte('[') + for i, c := range v { + if i > 0 { + p.buf.writeByte(' ') + } + p.fmt.fmtInteger(uint64(c), 10, unsigned, verb, ldigits) + } + p.buf.writeByte(']') + } + case 's': + p.fmt.fmtBs(v) + case 'x': + p.fmt.fmtBx(v, ldigits) + case 'X': + p.fmt.fmtBx(v, udigits) + case 'q': + p.fmt.fmtQ(string(v)) + default: + p.printValue(reflect.ValueOf(v), verb, 0) + } +} + +func (p *pp) fmtPointer(value reflect.Value, verb rune) { + var u uintptr + switch value.Kind() { + case reflect.Chan, reflect.Func, reflect.Map, reflect.Pointer, reflect.Slice, reflect.UnsafePointer: + u = uintptr(value.UnsafePointer()) + default: + p.badVerb(verb) + return + } + + switch verb { + case 'v': + if p.fmt.sharpV { + p.buf.writeByte('(') + p.buf.writeString(value.Type().String()) + p.buf.writeString(")(") + if u == 0 { + p.buf.writeString(nilString) + } else { + p.fmt0x64(uint64(u), true) + } + p.buf.writeByte(')') + } else { + if u == 0 { + p.fmt.padString(nilAngleString) + } else { + p.fmt0x64(uint64(u), !p.fmt.sharp) + } + } + case 'p': + p.fmt0x64(uint64(u), !p.fmt.sharp) + case 'b', 'o', 'd', 'x', 'X': + p.fmtInteger(uint64(u), unsigned, verb) + default: + p.badVerb(verb) + } +} + +func (p *pp) catchPanic(arg any, verb rune, method string) { + if err := recover(); err != nil { + // If it's a nil pointer, just say "<nil>". The likeliest causes are a + // Stringer that fails to guard against nil or a nil pointer for a + // value receiver, and in either case, "<nil>" is a nice result. + if v := reflect.ValueOf(arg); v.Kind() == reflect.Pointer && v.IsNil() { + p.buf.writeString(nilAngleString) + return + } + // Otherwise print a concise panic message. Most of the time the panic + // value will print itself nicely. + if p.panicking { + // Nested panics; the recursion in printArg cannot succeed. + panic(err) + } + + oldFlags := p.fmt.fmtFlags + // For this output we want default behavior. + p.fmt.clearflags() + + p.buf.writeString(percentBangString) + p.buf.writeRune(verb) + p.buf.writeString(panicString) + p.buf.writeString(method) + p.buf.writeString(" method: ") + p.panicking = true + p.printArg(err, 'v') + p.panicking = false + p.buf.writeByte(')') + + p.fmt.fmtFlags = oldFlags + } +} + +func (p *pp) handleMethods(verb rune) (handled bool) { + if p.erroring { + return + } + if verb == 'w' { + // It is invalid to use %w other than with Errorf or with a non-error arg. + _, ok := p.arg.(error) + if !ok || !p.wrapErrs { + p.badVerb(verb) + return true + } + // If the arg is a Formatter, pass 'v' as the verb to it. + verb = 'v' + } + + // Is it a Formatter? + if formatter, ok := p.arg.(Formatter); ok { + handled = true + defer p.catchPanic(p.arg, verb, "Format") + formatter.Format(p, verb) + return + } + + // If we're doing Go syntax and the argument knows how to supply it, take care of it now. + if p.fmt.sharpV { + if stringer, ok := p.arg.(GoStringer); ok { + handled = true + defer p.catchPanic(p.arg, verb, "GoString") + // Print the result of GoString unadorned. + p.fmt.fmtS(stringer.GoString()) + return + } + } else { + // If a string is acceptable according to the format, see if + // the value satisfies one of the string-valued interfaces. + // Println etc. set verb to %v, which is "stringable". + switch verb { + case 'v', 's', 'x', 'X', 'q': + // Is it an error or Stringer? + // The duplication in the bodies is necessary: + // setting handled and deferring catchPanic + // must happen before calling the method. + switch v := p.arg.(type) { + case error: + handled = true + defer p.catchPanic(p.arg, verb, "Error") + p.fmtString(v.Error(), verb) + return + + case Stringer: + handled = true + defer p.catchPanic(p.arg, verb, "String") + p.fmtString(v.String(), verb) + return + } + } + } + return false +} + +func (p *pp) printArg(arg any, verb rune) { + p.arg = arg + p.value = reflect.Value{} + + if arg == nil { + switch verb { + case 'T', 'v': + p.fmt.padString(nilAngleString) + default: + p.badVerb(verb) + } + return + } + + // Special processing considerations. + // %T (the value's type) and %p (its address) are special; we always do them first. + switch verb { + case 'T': + p.fmt.fmtS(reflect.TypeOf(arg).String()) + return + case 'p': + p.fmtPointer(reflect.ValueOf(arg), 'p') + return + } + + // Some types can be done without reflection. + switch f := arg.(type) { + case bool: + p.fmtBool(f, verb) + case float32: + p.fmtFloat(float64(f), 32, verb) + case float64: + p.fmtFloat(f, 64, verb) + case complex64: + p.fmtComplex(complex128(f), 64, verb) + case complex128: + p.fmtComplex(f, 128, verb) + case int: + p.fmtInteger(uint64(f), signed, verb) + case int8: + p.fmtInteger(uint64(f), signed, verb) + case int16: + p.fmtInteger(uint64(f), signed, verb) + case int32: + p.fmtInteger(uint64(f), signed, verb) + case int64: + p.fmtInteger(uint64(f), signed, verb) + case uint: + p.fmtInteger(uint64(f), unsigned, verb) + case uint8: + p.fmtInteger(uint64(f), unsigned, verb) + case uint16: + p.fmtInteger(uint64(f), unsigned, verb) + case uint32: + p.fmtInteger(uint64(f), unsigned, verb) + case uint64: + p.fmtInteger(f, unsigned, verb) + case uintptr: + p.fmtInteger(uint64(f), unsigned, verb) + case string: + p.fmtString(f, verb) + case []byte: + p.fmtBytes(f, verb, "[]byte") + case reflect.Value: + // Handle extractable values with special methods + // since printValue does not handle them at depth 0. + if f.IsValid() && f.CanInterface() { + p.arg = f.Interface() + if p.handleMethods(verb) { + return + } + } + p.printValue(f, verb, 0) + default: + // If the type is not simple, it might have methods. + if !p.handleMethods(verb) { + // Need to use reflection, since the type had no + // interface methods that could be used for formatting. + p.printValue(reflect.ValueOf(f), verb, 0) + } + } +} + +// printValue is similar to printArg but starts with a reflect value, not an interface{} value. +// It does not handle 'p' and 'T' verbs because these should have been already handled by printArg. +func (p *pp) printValue(value reflect.Value, verb rune, depth int) { + // Handle values with special methods if not already handled by printArg (depth == 0). + if depth > 0 && value.IsValid() && value.CanInterface() { + p.arg = value.Interface() + if p.handleMethods(verb) { + return + } + } + p.arg = nil + p.value = value + + switch f := value; value.Kind() { + case reflect.Invalid: + if depth == 0 { + p.buf.writeString(invReflectString) + } else { + switch verb { + case 'v': + p.buf.writeString(nilAngleString) + default: + p.badVerb(verb) + } + } + case reflect.Bool: + p.fmtBool(f.Bool(), verb) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + p.fmtInteger(uint64(f.Int()), signed, verb) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + p.fmtInteger(f.Uint(), unsigned, verb) + case reflect.Float32: + p.fmtFloat(f.Float(), 32, verb) + case reflect.Float64: + p.fmtFloat(f.Float(), 64, verb) + case reflect.Complex64: + p.fmtComplex(f.Complex(), 64, verb) + case reflect.Complex128: + p.fmtComplex(f.Complex(), 128, verb) + case reflect.String: + p.fmtString(f.String(), verb) + case reflect.Map: + if p.fmt.sharpV { + p.buf.writeString(f.Type().String()) + if f.IsNil() { + p.buf.writeString(nilParenString) + return + } + p.buf.writeByte('{') + } else { + p.buf.writeString(mapString) + } + sorted := fmtsort.Sort(f) + for i, key := range sorted.Key { + if i > 0 { + if p.fmt.sharpV { + p.buf.writeString(commaSpaceString) + } else { + p.buf.writeByte(' ') + } + } + p.printValue(key, verb, depth+1) + p.buf.writeByte(':') + p.printValue(sorted.Value[i], verb, depth+1) + } + if p.fmt.sharpV { + p.buf.writeByte('}') + } else { + p.buf.writeByte(']') + } + case reflect.Struct: + if p.fmt.sharpV { + p.buf.writeString(f.Type().String()) + } + p.buf.writeByte('{') + for i := 0; i < f.NumField(); i++ { + if i > 0 { + if p.fmt.sharpV { + p.buf.writeString(commaSpaceString) + } else { + p.buf.writeByte(' ') + } + } + if p.fmt.plusV || p.fmt.sharpV { + if name := f.Type().Field(i).Name; name != "" { + p.buf.writeString(name) + p.buf.writeByte(':') + } + } + p.printValue(getField(f, i), verb, depth+1) + } + p.buf.writeByte('}') + case reflect.Interface: + value := f.Elem() + if !value.IsValid() { + if p.fmt.sharpV { + p.buf.writeString(f.Type().String()) + p.buf.writeString(nilParenString) + } else { + p.buf.writeString(nilAngleString) + } + } else { + p.printValue(value, verb, depth+1) + } + case reflect.Array, reflect.Slice: + switch verb { + case 's', 'q', 'x', 'X': + // Handle byte and uint8 slices and arrays special for the above verbs. + t := f.Type() + if t.Elem().Kind() == reflect.Uint8 { + var bytes []byte + if f.Kind() == reflect.Slice || f.CanAddr() { + bytes = f.Bytes() + } else { + // We have an array, but we cannot Bytes() a non-addressable array, + // so we build a slice by hand. This is a rare case but it would be nice + // if reflection could help a little more. + bytes = make([]byte, f.Len()) + for i := range bytes { + bytes[i] = byte(f.Index(i).Uint()) + } + } + p.fmtBytes(bytes, verb, t.String()) + return + } + } + if p.fmt.sharpV { + p.buf.writeString(f.Type().String()) + if f.Kind() == reflect.Slice && f.IsNil() { + p.buf.writeString(nilParenString) + return + } + p.buf.writeByte('{') + for i := 0; i < f.Len(); i++ { + if i > 0 { + p.buf.writeString(commaSpaceString) + } + p.printValue(f.Index(i), verb, depth+1) + } + p.buf.writeByte('}') + } else { + p.buf.writeByte('[') + for i := 0; i < f.Len(); i++ { + if i > 0 { + p.buf.writeByte(' ') + } + p.printValue(f.Index(i), verb, depth+1) + } + p.buf.writeByte(']') + } + case reflect.Pointer: + // pointer to array or slice or struct? ok at top level + // but not embedded (avoid loops) + if depth == 0 && f.UnsafePointer() != nil { + switch a := f.Elem(); a.Kind() { + case reflect.Array, reflect.Slice, reflect.Struct, reflect.Map: + p.buf.writeByte('&') + p.printValue(a, verb, depth+1) + return + } + } + fallthrough + case reflect.Chan, reflect.Func, reflect.UnsafePointer: + p.fmtPointer(f, verb) + default: + p.unknownType(f) + } +} + +// intFromArg gets the argNumth element of a. On return, isInt reports whether the argument has integer type. +func intFromArg(a []any, argNum int) (num int, isInt bool, newArgNum int) { + newArgNum = argNum + if argNum < len(a) { + num, isInt = a[argNum].(int) // Almost always OK. + if !isInt { + // Work harder. + switch v := reflect.ValueOf(a[argNum]); v.Kind() { + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + n := v.Int() + if int64(int(n)) == n { + num = int(n) + isInt = true + } + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + n := v.Uint() + if int64(n) >= 0 && uint64(int(n)) == n { + num = int(n) + isInt = true + } + default: + // Already 0, false. + } + } + newArgNum = argNum + 1 + if tooLarge(num) { + num = 0 + isInt = false + } + } + return +} + +// parseArgNumber returns the value of the bracketed number, minus 1 +// (explicit argument numbers are one-indexed but we want zero-indexed). +// The opening bracket is known to be present at format[0]. +// The returned values are the index, the number of bytes to consume +// up to the closing paren, if present, and whether the number parsed +// ok. The bytes to consume will be 1 if no closing paren is present. +func parseArgNumber(format string) (index int, wid int, ok bool) { + // There must be at least 3 bytes: [n]. + if len(format) < 3 { + return 0, 1, false + } + + // Find closing bracket. + for i := 1; i < len(format); i++ { + if format[i] == ']' { + width, ok, newi := parsenum(format, 1, i) + if !ok || newi != i { + return 0, i + 1, false + } + return width - 1, i + 1, true // arg numbers are one-indexed and skip paren. + } + } + return 0, 1, false +} + +// argNumber returns the next argument to evaluate, which is either the value of the passed-in +// argNum or the value of the bracketed integer that begins format[i:]. It also returns +// the new value of i, that is, the index of the next byte of the format to process. +func (p *pp) argNumber(argNum int, format string, i int, numArgs int) (newArgNum, newi int, found bool) { + if len(format) <= i || format[i] != '[' { + return argNum, i, false + } + p.reordered = true + index, wid, ok := parseArgNumber(format[i:]) + if ok && 0 <= index && index < numArgs { + return index, i + wid, true + } + p.goodArgNum = false + return argNum, i + wid, ok +} + +func (p *pp) badArgNum(verb rune) { + p.buf.writeString(percentBangString) + p.buf.writeRune(verb) + p.buf.writeString(badIndexString) +} + +func (p *pp) missingArg(verb rune) { + p.buf.writeString(percentBangString) + p.buf.writeRune(verb) + p.buf.writeString(missingString) +} + +func (p *pp) doPrintf(format string, a []any) { + end := len(format) + argNum := 0 // we process one argument per non-trivial format + afterIndex := false // previous item in format was an index like [3]. + p.reordered = false +formatLoop: + for i := 0; i < end; { + p.goodArgNum = true + lasti := i + for i < end && format[i] != '%' { + i++ + } + if i > lasti { + p.buf.writeString(format[lasti:i]) + } + if i >= end { + // done processing format string + break + } + + // Process one verb + i++ + + // Do we have flags? + p.fmt.clearflags() + simpleFormat: + for ; i < end; i++ { + c := format[i] + switch c { + case '#': + p.fmt.sharp = true + case '0': + p.fmt.zero = !p.fmt.minus // Only allow zero padding to the left. + case '+': + p.fmt.plus = true + case '-': + p.fmt.minus = true + p.fmt.zero = false // Do not pad with zeros to the right. + case ' ': + p.fmt.space = true + default: + // Fast path for common case of ascii lower case simple verbs + // without precision or width or argument indices. + if 'a' <= c && c <= 'z' && argNum < len(a) { + switch c { + case 'w': + p.wrappedErrs = append(p.wrappedErrs, argNum) + fallthrough + case 'v': + // Go syntax + p.fmt.sharpV = p.fmt.sharp + p.fmt.sharp = false + // Struct-field syntax + p.fmt.plusV = p.fmt.plus + p.fmt.plus = false + } + p.printArg(a[argNum], rune(c)) + argNum++ + i++ + continue formatLoop + } + // Format is more complex than simple flags and a verb or is malformed. + break simpleFormat + } + } + + // Do we have an explicit argument index? + argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a)) + + // Do we have width? + if i < end && format[i] == '*' { + i++ + p.fmt.wid, p.fmt.widPresent, argNum = intFromArg(a, argNum) + + if !p.fmt.widPresent { + p.buf.writeString(badWidthString) + } + + // We have a negative width, so take its value and ensure + // that the minus flag is set + if p.fmt.wid < 0 { + p.fmt.wid = -p.fmt.wid + p.fmt.minus = true + p.fmt.zero = false // Do not pad with zeros to the right. + } + afterIndex = false + } else { + p.fmt.wid, p.fmt.widPresent, i = parsenum(format, i, end) + if afterIndex && p.fmt.widPresent { // "%[3]2d" + p.goodArgNum = false + } + } + + // Do we have precision? + if i+1 < end && format[i] == '.' { + i++ + if afterIndex { // "%[3].2d" + p.goodArgNum = false + } + argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a)) + if i < end && format[i] == '*' { + i++ + p.fmt.prec, p.fmt.precPresent, argNum = intFromArg(a, argNum) + // Negative precision arguments don't make sense + if p.fmt.prec < 0 { + p.fmt.prec = 0 + p.fmt.precPresent = false + } + if !p.fmt.precPresent { + p.buf.writeString(badPrecString) + } + afterIndex = false + } else { + p.fmt.prec, p.fmt.precPresent, i = parsenum(format, i, end) + if !p.fmt.precPresent { + p.fmt.prec = 0 + p.fmt.precPresent = true + } + } + } + + if !afterIndex { + argNum, i, afterIndex = p.argNumber(argNum, format, i, len(a)) + } + + if i >= end { + p.buf.writeString(noVerbString) + break + } + + verb, size := rune(format[i]), 1 + if verb >= utf8.RuneSelf { + verb, size = utf8.DecodeRuneInString(format[i:]) + } + i += size + + switch { + case verb == '%': // Percent does not absorb operands and ignores f.wid and f.prec. + p.buf.writeByte('%') + case !p.goodArgNum: + p.badArgNum(verb) + case argNum >= len(a): // No argument left over to print for the current verb. + p.missingArg(verb) + case verb == 'w': + p.wrappedErrs = append(p.wrappedErrs, argNum) + fallthrough + case verb == 'v': + // Go syntax + p.fmt.sharpV = p.fmt.sharp + p.fmt.sharp = false + // Struct-field syntax + p.fmt.plusV = p.fmt.plus + p.fmt.plus = false + fallthrough + default: + p.printArg(a[argNum], verb) + argNum++ + } + } + + // Check for extra arguments unless the call accessed the arguments + // out of order, in which case it's too expensive to detect if they've all + // been used and arguably OK if they're not. + if !p.reordered && argNum < len(a) { + p.fmt.clearflags() + p.buf.writeString(extraString) + for i, arg := range a[argNum:] { + if i > 0 { + p.buf.writeString(commaSpaceString) + } + if arg == nil { + p.buf.writeString(nilAngleString) + } else { + p.buf.writeString(reflect.TypeOf(arg).String()) + p.buf.writeByte('=') + p.printArg(arg, 'v') + } + } + p.buf.writeByte(')') + } +} + +func (p *pp) doPrint(a []any) { + prevString := false + for argNum, arg := range a { + isString := arg != nil && reflect.TypeOf(arg).Kind() == reflect.String + // Add a space between two non-string arguments. + if argNum > 0 && !isString && !prevString { + p.buf.writeByte(' ') + } + p.printArg(arg, 'v') + prevString = isString + } +} + +// doPrintln is like doPrint but always adds a space between arguments +// and a newline after the last argument. +func (p *pp) doPrintln(a []any) { + for argNum, arg := range a { + if argNum > 0 { + p.buf.writeByte(' ') + } + p.printArg(arg, 'v') + } + p.buf.writeByte('\n') +} diff --git a/contrib/go/_std_1.22/src/fmt/scan.go b/contrib/go/_std_1.22/src/fmt/scan.go new file mode 100644 index 0000000000..5dd0971642 --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/scan.go @@ -0,0 +1,1238 @@ +// Copyright 2010 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package fmt + +import ( + "errors" + "io" + "math" + "os" + "reflect" + "strconv" + "sync" + "unicode/utf8" +) + +// ScanState represents the scanner state passed to custom scanners. +// Scanners may do rune-at-a-time scanning or ask the ScanState +// to discover the next space-delimited token. +type ScanState interface { + // ReadRune reads the next rune (Unicode code point) from the input. + // If invoked during Scanln, Fscanln, or Sscanln, ReadRune() will + // return EOF after returning the first '\n' or when reading beyond + // the specified width. + ReadRune() (r rune, size int, err error) + // UnreadRune causes the next call to ReadRune to return the same rune. + UnreadRune() error + // SkipSpace skips space in the input. Newlines are treated appropriately + // for the operation being performed; see the package documentation + // for more information. + SkipSpace() + // Token skips space in the input if skipSpace is true, then returns the + // run of Unicode code points c satisfying f(c). If f is nil, + // !unicode.IsSpace(c) is used; that is, the token will hold non-space + // characters. Newlines are treated appropriately for the operation being + // performed; see the package documentation for more information. + // The returned slice points to shared data that may be overwritten + // by the next call to Token, a call to a Scan function using the ScanState + // as input, or when the calling Scan method returns. + Token(skipSpace bool, f func(rune) bool) (token []byte, err error) + // Width returns the value of the width option and whether it has been set. + // The unit is Unicode code points. + Width() (wid int, ok bool) + // Because ReadRune is implemented by the interface, Read should never be + // called by the scanning routines and a valid implementation of + // ScanState may choose always to return an error from Read. + Read(buf []byte) (n int, err error) +} + +// Scanner is implemented by any value that has a Scan method, which scans +// the input for the representation of a value and stores the result in the +// receiver, which must be a pointer to be useful. The Scan method is called +// for any argument to Scan, Scanf, or Scanln that implements it. +type Scanner interface { + Scan(state ScanState, verb rune) error +} + +// Scan scans text read from standard input, storing successive +// space-separated values into successive arguments. Newlines count +// as space. It returns the number of items successfully scanned. +// If that is less than the number of arguments, err will report why. +func Scan(a ...any) (n int, err error) { + return Fscan(os.Stdin, a...) +} + +// Scanln is similar to Scan, but stops scanning at a newline and +// after the final item there must be a newline or EOF. +func Scanln(a ...any) (n int, err error) { + return Fscanln(os.Stdin, a...) +} + +// Scanf scans text read from standard input, storing successive +// space-separated values into successive arguments as determined by +// the format. It returns the number of items successfully scanned. +// If that is less than the number of arguments, err will report why. +// Newlines in the input must match newlines in the format. +// The one exception: the verb %c always scans the next rune in the +// input, even if it is a space (or tab etc.) or newline. +func Scanf(format string, a ...any) (n int, err error) { + return Fscanf(os.Stdin, format, a...) +} + +type stringReader string + +func (r *stringReader) Read(b []byte) (n int, err error) { + n = copy(b, *r) + *r = (*r)[n:] + if n == 0 { + err = io.EOF + } + return +} + +// Sscan scans the argument string, storing successive space-separated +// values into successive arguments. Newlines count as space. It +// returns the number of items successfully scanned. If that is less +// than the number of arguments, err will report why. +func Sscan(str string, a ...any) (n int, err error) { + return Fscan((*stringReader)(&str), a...) +} + +// Sscanln is similar to Sscan, but stops scanning at a newline and +// after the final item there must be a newline or EOF. +func Sscanln(str string, a ...any) (n int, err error) { + return Fscanln((*stringReader)(&str), a...) +} + +// Sscanf scans the argument string, storing successive space-separated +// values into successive arguments as determined by the format. It +// returns the number of items successfully parsed. +// Newlines in the input must match newlines in the format. +func Sscanf(str string, format string, a ...any) (n int, err error) { + return Fscanf((*stringReader)(&str), format, a...) +} + +// Fscan scans text read from r, storing successive space-separated +// values into successive arguments. Newlines count as space. It +// returns the number of items successfully scanned. If that is less +// than the number of arguments, err will report why. +func Fscan(r io.Reader, a ...any) (n int, err error) { + s, old := newScanState(r, true, false) + n, err = s.doScan(a) + s.free(old) + return +} + +// Fscanln is similar to Fscan, but stops scanning at a newline and +// after the final item there must be a newline or EOF. +func Fscanln(r io.Reader, a ...any) (n int, err error) { + s, old := newScanState(r, false, true) + n, err = s.doScan(a) + s.free(old) + return +} + +// Fscanf scans text read from r, storing successive space-separated +// values into successive arguments as determined by the format. It +// returns the number of items successfully parsed. +// Newlines in the input must match newlines in the format. +func Fscanf(r io.Reader, format string, a ...any) (n int, err error) { + s, old := newScanState(r, false, false) + n, err = s.doScanf(format, a) + s.free(old) + return +} + +// scanError represents an error generated by the scanning software. +// It's used as a unique signature to identify such errors when recovering. +type scanError struct { + err error +} + +const eof = -1 + +// ss is the internal implementation of ScanState. +type ss struct { + rs io.RuneScanner // where to read input + buf buffer // token accumulator + count int // runes consumed so far. + atEOF bool // already read EOF + ssave +} + +// ssave holds the parts of ss that need to be +// saved and restored on recursive scans. +type ssave struct { + validSave bool // is or was a part of an actual ss. + nlIsEnd bool // whether newline terminates scan + nlIsSpace bool // whether newline counts as white space + argLimit int // max value of ss.count for this arg; argLimit <= limit + limit int // max value of ss.count. + maxWid int // width of this arg. +} + +// The Read method is only in ScanState so that ScanState +// satisfies io.Reader. It will never be called when used as +// intended, so there is no need to make it actually work. +func (s *ss) Read(buf []byte) (n int, err error) { + return 0, errors.New("ScanState's Read should not be called. Use ReadRune") +} + +func (s *ss) ReadRune() (r rune, size int, err error) { + if s.atEOF || s.count >= s.argLimit { + err = io.EOF + return + } + + r, size, err = s.rs.ReadRune() + if err == nil { + s.count++ + if s.nlIsEnd && r == '\n' { + s.atEOF = true + } + } else if err == io.EOF { + s.atEOF = true + } + return +} + +func (s *ss) Width() (wid int, ok bool) { + if s.maxWid == hugeWid { + return 0, false + } + return s.maxWid, true +} + +// The public method returns an error; this private one panics. +// If getRune reaches EOF, the return value is EOF (-1). +func (s *ss) getRune() (r rune) { + r, _, err := s.ReadRune() + if err != nil { + if err == io.EOF { + return eof + } + s.error(err) + } + return +} + +// mustReadRune turns io.EOF into a panic(io.ErrUnexpectedEOF). +// It is called in cases such as string scanning where an EOF is a +// syntax error. +func (s *ss) mustReadRune() (r rune) { + r = s.getRune() + if r == eof { + s.error(io.ErrUnexpectedEOF) + } + return +} + +func (s *ss) UnreadRune() error { + s.rs.UnreadRune() + s.atEOF = false + s.count-- + return nil +} + +func (s *ss) error(err error) { + panic(scanError{err}) +} + +func (s *ss) errorString(err string) { + panic(scanError{errors.New(err)}) +} + +func (s *ss) Token(skipSpace bool, f func(rune) bool) (tok []byte, err error) { + defer func() { + if e := recover(); e != nil { + if se, ok := e.(scanError); ok { + err = se.err + } else { + panic(e) + } + } + }() + if f == nil { + f = notSpace + } + s.buf = s.buf[:0] + tok = s.token(skipSpace, f) + return +} + +// space is a copy of the unicode.White_Space ranges, +// to avoid depending on package unicode. +var space = [][2]uint16{ + {0x0009, 0x000d}, + {0x0020, 0x0020}, + {0x0085, 0x0085}, + {0x00a0, 0x00a0}, + {0x1680, 0x1680}, + {0x2000, 0x200a}, + {0x2028, 0x2029}, + {0x202f, 0x202f}, + {0x205f, 0x205f}, + {0x3000, 0x3000}, +} + +func isSpace(r rune) bool { + if r >= 1<<16 { + return false + } + rx := uint16(r) + for _, rng := range space { + if rx < rng[0] { + return false + } + if rx <= rng[1] { + return true + } + } + return false +} + +// notSpace is the default scanning function used in Token. +func notSpace(r rune) bool { + return !isSpace(r) +} + +// readRune is a structure to enable reading UTF-8 encoded code points +// from an io.Reader. It is used if the Reader given to the scanner does +// not already implement io.RuneScanner. +type readRune struct { + reader io.Reader + buf [utf8.UTFMax]byte // used only inside ReadRune + pending int // number of bytes in pendBuf; only >0 for bad UTF-8 + pendBuf [utf8.UTFMax]byte // bytes left over + peekRune rune // if >=0 next rune; when <0 is ^(previous Rune) +} + +// readByte returns the next byte from the input, which may be +// left over from a previous read if the UTF-8 was ill-formed. +func (r *readRune) readByte() (b byte, err error) { + if r.pending > 0 { + b = r.pendBuf[0] + copy(r.pendBuf[0:], r.pendBuf[1:]) + r.pending-- + return + } + n, err := io.ReadFull(r.reader, r.pendBuf[:1]) + if n != 1 { + return 0, err + } + return r.pendBuf[0], err +} + +// ReadRune returns the next UTF-8 encoded code point from the +// io.Reader inside r. +func (r *readRune) ReadRune() (rr rune, size int, err error) { + if r.peekRune >= 0 { + rr = r.peekRune + r.peekRune = ^r.peekRune + size = utf8.RuneLen(rr) + return + } + r.buf[0], err = r.readByte() + if err != nil { + return + } + if r.buf[0] < utf8.RuneSelf { // fast check for common ASCII case + rr = rune(r.buf[0]) + size = 1 // Known to be 1. + // Flip the bits of the rune so it's available to UnreadRune. + r.peekRune = ^rr + return + } + var n int + for n = 1; !utf8.FullRune(r.buf[:n]); n++ { + r.buf[n], err = r.readByte() + if err != nil { + if err == io.EOF { + err = nil + break + } + return + } + } + rr, size = utf8.DecodeRune(r.buf[:n]) + if size < n { // an error, save the bytes for the next read + copy(r.pendBuf[r.pending:], r.buf[size:n]) + r.pending += n - size + } + // Flip the bits of the rune so it's available to UnreadRune. + r.peekRune = ^rr + return +} + +func (r *readRune) UnreadRune() error { + if r.peekRune >= 0 { + return errors.New("fmt: scanning called UnreadRune with no rune available") + } + // Reverse bit flip of previously read rune to obtain valid >=0 state. + r.peekRune = ^r.peekRune + return nil +} + +var ssFree = sync.Pool{ + New: func() any { return new(ss) }, +} + +// newScanState allocates a new ss struct or grab a cached one. +func newScanState(r io.Reader, nlIsSpace, nlIsEnd bool) (s *ss, old ssave) { + s = ssFree.Get().(*ss) + if rs, ok := r.(io.RuneScanner); ok { + s.rs = rs + } else { + s.rs = &readRune{reader: r, peekRune: -1} + } + s.nlIsSpace = nlIsSpace + s.nlIsEnd = nlIsEnd + s.atEOF = false + s.limit = hugeWid + s.argLimit = hugeWid + s.maxWid = hugeWid + s.validSave = true + s.count = 0 + return +} + +// free saves used ss structs in ssFree; avoid an allocation per invocation. +func (s *ss) free(old ssave) { + // If it was used recursively, just restore the old state. + if old.validSave { + s.ssave = old + return + } + // Don't hold on to ss structs with large buffers. + if cap(s.buf) > 1024 { + return + } + s.buf = s.buf[:0] + s.rs = nil + ssFree.Put(s) +} + +// SkipSpace provides Scan methods the ability to skip space and newline +// characters in keeping with the current scanning mode set by format strings +// and Scan/Scanln. +func (s *ss) SkipSpace() { + for { + r := s.getRune() + if r == eof { + return + } + if r == '\r' && s.peek("\n") { + continue + } + if r == '\n' { + if s.nlIsSpace { + continue + } + s.errorString("unexpected newline") + return + } + if !isSpace(r) { + s.UnreadRune() + break + } + } +} + +// token returns the next space-delimited string from the input. It +// skips white space. For Scanln, it stops at newlines. For Scan, +// newlines are treated as spaces. +func (s *ss) token(skipSpace bool, f func(rune) bool) []byte { + if skipSpace { + s.SkipSpace() + } + // read until white space or newline + for { + r := s.getRune() + if r == eof { + break + } + if !f(r) { + s.UnreadRune() + break + } + s.buf.writeRune(r) + } + return s.buf +} + +var errComplex = errors.New("syntax error scanning complex number") +var errBool = errors.New("syntax error scanning boolean") + +func indexRune(s string, r rune) int { + for i, c := range s { + if c == r { + return i + } + } + return -1 +} + +// consume reads the next rune in the input and reports whether it is in the ok string. +// If accept is true, it puts the character into the input token. +func (s *ss) consume(ok string, accept bool) bool { + r := s.getRune() + if r == eof { + return false + } + if indexRune(ok, r) >= 0 { + if accept { + s.buf.writeRune(r) + } + return true + } + if r != eof && accept { + s.UnreadRune() + } + return false +} + +// peek reports whether the next character is in the ok string, without consuming it. +func (s *ss) peek(ok string) bool { + r := s.getRune() + if r != eof { + s.UnreadRune() + } + return indexRune(ok, r) >= 0 +} + +func (s *ss) notEOF() { + // Guarantee there is data to be read. + if r := s.getRune(); r == eof { + panic(io.EOF) + } + s.UnreadRune() +} + +// accept checks the next rune in the input. If it's a byte (sic) in the string, it puts it in the +// buffer and returns true. Otherwise it return false. +func (s *ss) accept(ok string) bool { + return s.consume(ok, true) +} + +// okVerb verifies that the verb is present in the list, setting s.err appropriately if not. +func (s *ss) okVerb(verb rune, okVerbs, typ string) bool { + for _, v := range okVerbs { + if v == verb { + return true + } + } + s.errorString("bad verb '%" + string(verb) + "' for " + typ) + return false +} + +// scanBool returns the value of the boolean represented by the next token. +func (s *ss) scanBool(verb rune) bool { + s.SkipSpace() + s.notEOF() + if !s.okVerb(verb, "tv", "boolean") { + return false + } + // Syntax-checking a boolean is annoying. We're not fastidious about case. + switch s.getRune() { + case '0': + return false + case '1': + return true + case 't', 'T': + if s.accept("rR") && (!s.accept("uU") || !s.accept("eE")) { + s.error(errBool) + } + return true + case 'f', 'F': + if s.accept("aA") && (!s.accept("lL") || !s.accept("sS") || !s.accept("eE")) { + s.error(errBool) + } + return false + } + return false +} + +// Numerical elements +const ( + binaryDigits = "01" + octalDigits = "01234567" + decimalDigits = "0123456789" + hexadecimalDigits = "0123456789aAbBcCdDeEfF" + sign = "+-" + period = "." + exponent = "eEpP" +) + +// getBase returns the numeric base represented by the verb and its digit string. +func (s *ss) getBase(verb rune) (base int, digits string) { + s.okVerb(verb, "bdoUxXv", "integer") // sets s.err + base = 10 + digits = decimalDigits + switch verb { + case 'b': + base = 2 + digits = binaryDigits + case 'o': + base = 8 + digits = octalDigits + case 'x', 'X', 'U': + base = 16 + digits = hexadecimalDigits + } + return +} + +// scanNumber returns the numerical string with specified digits starting here. +func (s *ss) scanNumber(digits string, haveDigits bool) string { + if !haveDigits { + s.notEOF() + if !s.accept(digits) { + s.errorString("expected integer") + } + } + for s.accept(digits) { + } + return string(s.buf) +} + +// scanRune returns the next rune value in the input. +func (s *ss) scanRune(bitSize int) int64 { + s.notEOF() + r := s.getRune() + n := uint(bitSize) + x := (int64(r) << (64 - n)) >> (64 - n) + if x != int64(r) { + s.errorString("overflow on character value " + string(r)) + } + return int64(r) +} + +// scanBasePrefix reports whether the integer begins with a base prefix +// and returns the base, digit string, and whether a zero was found. +// It is called only if the verb is %v. +func (s *ss) scanBasePrefix() (base int, digits string, zeroFound bool) { + if !s.peek("0") { + return 0, decimalDigits + "_", false + } + s.accept("0") + // Special cases for 0, 0b, 0o, 0x. + switch { + case s.peek("bB"): + s.consume("bB", true) + return 0, binaryDigits + "_", true + case s.peek("oO"): + s.consume("oO", true) + return 0, octalDigits + "_", true + case s.peek("xX"): + s.consume("xX", true) + return 0, hexadecimalDigits + "_", true + default: + return 0, octalDigits + "_", true + } +} + +// scanInt returns the value of the integer represented by the next +// token, checking for overflow. Any error is stored in s.err. +func (s *ss) scanInt(verb rune, bitSize int) int64 { + if verb == 'c' { + return s.scanRune(bitSize) + } + s.SkipSpace() + s.notEOF() + base, digits := s.getBase(verb) + haveDigits := false + if verb == 'U' { + if !s.consume("U", false) || !s.consume("+", false) { + s.errorString("bad unicode format ") + } + } else { + s.accept(sign) // If there's a sign, it will be left in the token buffer. + if verb == 'v' { + base, digits, haveDigits = s.scanBasePrefix() + } + } + tok := s.scanNumber(digits, haveDigits) + i, err := strconv.ParseInt(tok, base, 64) + if err != nil { + s.error(err) + } + n := uint(bitSize) + x := (i << (64 - n)) >> (64 - n) + if x != i { + s.errorString("integer overflow on token " + tok) + } + return i +} + +// scanUint returns the value of the unsigned integer represented +// by the next token, checking for overflow. Any error is stored in s.err. +func (s *ss) scanUint(verb rune, bitSize int) uint64 { + if verb == 'c' { + return uint64(s.scanRune(bitSize)) + } + s.SkipSpace() + s.notEOF() + base, digits := s.getBase(verb) + haveDigits := false + if verb == 'U' { + if !s.consume("U", false) || !s.consume("+", false) { + s.errorString("bad unicode format ") + } + } else if verb == 'v' { + base, digits, haveDigits = s.scanBasePrefix() + } + tok := s.scanNumber(digits, haveDigits) + i, err := strconv.ParseUint(tok, base, 64) + if err != nil { + s.error(err) + } + n := uint(bitSize) + x := (i << (64 - n)) >> (64 - n) + if x != i { + s.errorString("unsigned integer overflow on token " + tok) + } + return i +} + +// floatToken returns the floating-point number starting here, no longer than swid +// if the width is specified. It's not rigorous about syntax because it doesn't check that +// we have at least some digits, but Atof will do that. +func (s *ss) floatToken() string { + s.buf = s.buf[:0] + // NaN? + if s.accept("nN") && s.accept("aA") && s.accept("nN") { + return string(s.buf) + } + // leading sign? + s.accept(sign) + // Inf? + if s.accept("iI") && s.accept("nN") && s.accept("fF") { + return string(s.buf) + } + digits := decimalDigits + "_" + exp := exponent + if s.accept("0") && s.accept("xX") { + digits = hexadecimalDigits + "_" + exp = "pP" + } + // digits? + for s.accept(digits) { + } + // decimal point? + if s.accept(period) { + // fraction? + for s.accept(digits) { + } + } + // exponent? + if s.accept(exp) { + // leading sign? + s.accept(sign) + // digits? + for s.accept(decimalDigits + "_") { + } + } + return string(s.buf) +} + +// complexTokens returns the real and imaginary parts of the complex number starting here. +// The number might be parenthesized and has the format (N+Ni) where N is a floating-point +// number and there are no spaces within. +func (s *ss) complexTokens() (real, imag string) { + // TODO: accept N and Ni independently? + parens := s.accept("(") + real = s.floatToken() + s.buf = s.buf[:0] + // Must now have a sign. + if !s.accept("+-") { + s.error(errComplex) + } + // Sign is now in buffer + imagSign := string(s.buf) + imag = s.floatToken() + if !s.accept("i") { + s.error(errComplex) + } + if parens && !s.accept(")") { + s.error(errComplex) + } + return real, imagSign + imag +} + +func hasX(s string) bool { + for i := 0; i < len(s); i++ { + if s[i] == 'x' || s[i] == 'X' { + return true + } + } + return false +} + +// convertFloat converts the string to a float64value. +func (s *ss) convertFloat(str string, n int) float64 { + // strconv.ParseFloat will handle "+0x1.fp+2", + // but we have to implement our non-standard + // decimal+binary exponent mix (1.2p4) ourselves. + if p := indexRune(str, 'p'); p >= 0 && !hasX(str) { + // Atof doesn't handle power-of-2 exponents, + // but they're easy to evaluate. + f, err := strconv.ParseFloat(str[:p], n) + if err != nil { + // Put full string into error. + if e, ok := err.(*strconv.NumError); ok { + e.Num = str + } + s.error(err) + } + m, err := strconv.Atoi(str[p+1:]) + if err != nil { + // Put full string into error. + if e, ok := err.(*strconv.NumError); ok { + e.Num = str + } + s.error(err) + } + return math.Ldexp(f, m) + } + f, err := strconv.ParseFloat(str, n) + if err != nil { + s.error(err) + } + return f +} + +// scanComplex converts the next token to a complex128 value. +// The atof argument is a type-specific reader for the underlying type. +// If we're reading complex64, atof will parse float32s and convert them +// to float64's to avoid reproducing this code for each complex type. +func (s *ss) scanComplex(verb rune, n int) complex128 { + if !s.okVerb(verb, floatVerbs, "complex") { + return 0 + } + s.SkipSpace() + s.notEOF() + sreal, simag := s.complexTokens() + real := s.convertFloat(sreal, n/2) + imag := s.convertFloat(simag, n/2) + return complex(real, imag) +} + +// convertString returns the string represented by the next input characters. +// The format of the input is determined by the verb. +func (s *ss) convertString(verb rune) (str string) { + if !s.okVerb(verb, "svqxX", "string") { + return "" + } + s.SkipSpace() + s.notEOF() + switch verb { + case 'q': + str = s.quotedString() + case 'x', 'X': + str = s.hexString() + default: + str = string(s.token(true, notSpace)) // %s and %v just return the next word + } + return +} + +// quotedString returns the double- or back-quoted string represented by the next input characters. +func (s *ss) quotedString() string { + s.notEOF() + quote := s.getRune() + switch quote { + case '`': + // Back-quoted: Anything goes until EOF or back quote. + for { + r := s.mustReadRune() + if r == quote { + break + } + s.buf.writeRune(r) + } + return string(s.buf) + case '"': + // Double-quoted: Include the quotes and let strconv.Unquote do the backslash escapes. + s.buf.writeByte('"') + for { + r := s.mustReadRune() + s.buf.writeRune(r) + if r == '\\' { + // In a legal backslash escape, no matter how long, only the character + // immediately after the escape can itself be a backslash or quote. + // Thus we only need to protect the first character after the backslash. + s.buf.writeRune(s.mustReadRune()) + } else if r == '"' { + break + } + } + result, err := strconv.Unquote(string(s.buf)) + if err != nil { + s.error(err) + } + return result + default: + s.errorString("expected quoted string") + } + return "" +} + +// hexDigit returns the value of the hexadecimal digit. +func hexDigit(d rune) (int, bool) { + digit := int(d) + switch digit { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + return digit - '0', true + case 'a', 'b', 'c', 'd', 'e', 'f': + return 10 + digit - 'a', true + case 'A', 'B', 'C', 'D', 'E', 'F': + return 10 + digit - 'A', true + } + return -1, false +} + +// hexByte returns the next hex-encoded (two-character) byte from the input. +// It returns ok==false if the next bytes in the input do not encode a hex byte. +// If the first byte is hex and the second is not, processing stops. +func (s *ss) hexByte() (b byte, ok bool) { + rune1 := s.getRune() + if rune1 == eof { + return + } + value1, ok := hexDigit(rune1) + if !ok { + s.UnreadRune() + return + } + value2, ok := hexDigit(s.mustReadRune()) + if !ok { + s.errorString("illegal hex digit") + return + } + return byte(value1<<4 | value2), true +} + +// hexString returns the space-delimited hexpair-encoded string. +func (s *ss) hexString() string { + s.notEOF() + for { + b, ok := s.hexByte() + if !ok { + break + } + s.buf.writeByte(b) + } + if len(s.buf) == 0 { + s.errorString("no hex data for %x string") + return "" + } + return string(s.buf) +} + +const ( + floatVerbs = "beEfFgGv" + + hugeWid = 1 << 30 + + intBits = 32 << (^uint(0) >> 63) + uintptrBits = 32 << (^uintptr(0) >> 63) +) + +// scanPercent scans a literal percent character. +func (s *ss) scanPercent() { + s.SkipSpace() + s.notEOF() + if !s.accept("%") { + s.errorString("missing literal %") + } +} + +// scanOne scans a single value, deriving the scanner from the type of the argument. +func (s *ss) scanOne(verb rune, arg any) { + s.buf = s.buf[:0] + var err error + // If the parameter has its own Scan method, use that. + if v, ok := arg.(Scanner); ok { + err = v.Scan(s, verb) + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + s.error(err) + } + return + } + + switch v := arg.(type) { + case *bool: + *v = s.scanBool(verb) + case *complex64: + *v = complex64(s.scanComplex(verb, 64)) + case *complex128: + *v = s.scanComplex(verb, 128) + case *int: + *v = int(s.scanInt(verb, intBits)) + case *int8: + *v = int8(s.scanInt(verb, 8)) + case *int16: + *v = int16(s.scanInt(verb, 16)) + case *int32: + *v = int32(s.scanInt(verb, 32)) + case *int64: + *v = s.scanInt(verb, 64) + case *uint: + *v = uint(s.scanUint(verb, intBits)) + case *uint8: + *v = uint8(s.scanUint(verb, 8)) + case *uint16: + *v = uint16(s.scanUint(verb, 16)) + case *uint32: + *v = uint32(s.scanUint(verb, 32)) + case *uint64: + *v = s.scanUint(verb, 64) + case *uintptr: + *v = uintptr(s.scanUint(verb, uintptrBits)) + // Floats are tricky because you want to scan in the precision of the result, not + // scan in high precision and convert, in order to preserve the correct error condition. + case *float32: + if s.okVerb(verb, floatVerbs, "float32") { + s.SkipSpace() + s.notEOF() + *v = float32(s.convertFloat(s.floatToken(), 32)) + } + case *float64: + if s.okVerb(verb, floatVerbs, "float64") { + s.SkipSpace() + s.notEOF() + *v = s.convertFloat(s.floatToken(), 64) + } + case *string: + *v = s.convertString(verb) + case *[]byte: + // We scan to string and convert so we get a copy of the data. + // If we scanned to bytes, the slice would point at the buffer. + *v = []byte(s.convertString(verb)) + default: + val := reflect.ValueOf(v) + ptr := val + if ptr.Kind() != reflect.Pointer { + s.errorString("type not a pointer: " + val.Type().String()) + return + } + switch v := ptr.Elem(); v.Kind() { + case reflect.Bool: + v.SetBool(s.scanBool(verb)) + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + v.SetInt(s.scanInt(verb, v.Type().Bits())) + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + v.SetUint(s.scanUint(verb, v.Type().Bits())) + case reflect.String: + v.SetString(s.convertString(verb)) + case reflect.Slice: + // For now, can only handle (renamed) []byte. + typ := v.Type() + if typ.Elem().Kind() != reflect.Uint8 { + s.errorString("can't scan type: " + val.Type().String()) + } + str := s.convertString(verb) + v.Set(reflect.MakeSlice(typ, len(str), len(str))) + for i := 0; i < len(str); i++ { + v.Index(i).SetUint(uint64(str[i])) + } + case reflect.Float32, reflect.Float64: + s.SkipSpace() + s.notEOF() + v.SetFloat(s.convertFloat(s.floatToken(), v.Type().Bits())) + case reflect.Complex64, reflect.Complex128: + v.SetComplex(s.scanComplex(verb, v.Type().Bits())) + default: + s.errorString("can't scan type: " + val.Type().String()) + } + } +} + +// errorHandler turns local panics into error returns. +func errorHandler(errp *error) { + if e := recover(); e != nil { + if se, ok := e.(scanError); ok { // catch local error + *errp = se.err + } else if eof, ok := e.(error); ok && eof == io.EOF { // out of input + *errp = eof + } else { + panic(e) + } + } +} + +// doScan does the real work for scanning without a format string. +func (s *ss) doScan(a []any) (numProcessed int, err error) { + defer errorHandler(&err) + for _, arg := range a { + s.scanOne('v', arg) + numProcessed++ + } + // Check for newline (or EOF) if required (Scanln etc.). + if s.nlIsEnd { + for { + r := s.getRune() + if r == '\n' || r == eof { + break + } + if !isSpace(r) { + s.errorString("expected newline") + break + } + } + } + return +} + +// advance determines whether the next characters in the input match +// those of the format. It returns the number of bytes (sic) consumed +// in the format. All runs of space characters in either input or +// format behave as a single space. Newlines are special, though: +// newlines in the format must match those in the input and vice versa. +// This routine also handles the %% case. If the return value is zero, +// either format starts with a % (with no following %) or the input +// is empty. If it is negative, the input did not match the string. +func (s *ss) advance(format string) (i int) { + for i < len(format) { + fmtc, w := utf8.DecodeRuneInString(format[i:]) + + // Space processing. + // In the rest of this comment "space" means spaces other than newline. + // Newline in the format matches input of zero or more spaces and then newline or end-of-input. + // Spaces in the format before the newline are collapsed into the newline. + // Spaces in the format after the newline match zero or more spaces after the corresponding input newline. + // Other spaces in the format match input of one or more spaces or end-of-input. + if isSpace(fmtc) { + newlines := 0 + trailingSpace := false + for isSpace(fmtc) && i < len(format) { + if fmtc == '\n' { + newlines++ + trailingSpace = false + } else { + trailingSpace = true + } + i += w + fmtc, w = utf8.DecodeRuneInString(format[i:]) + } + for j := 0; j < newlines; j++ { + inputc := s.getRune() + for isSpace(inputc) && inputc != '\n' { + inputc = s.getRune() + } + if inputc != '\n' && inputc != eof { + s.errorString("newline in format does not match input") + } + } + if trailingSpace { + inputc := s.getRune() + if newlines == 0 { + // If the trailing space stood alone (did not follow a newline), + // it must find at least one space to consume. + if !isSpace(inputc) && inputc != eof { + s.errorString("expected space in input to match format") + } + if inputc == '\n' { + s.errorString("newline in input does not match format") + } + } + for isSpace(inputc) && inputc != '\n' { + inputc = s.getRune() + } + if inputc != eof { + s.UnreadRune() + } + } + continue + } + + // Verbs. + if fmtc == '%' { + // % at end of string is an error. + if i+w == len(format) { + s.errorString("missing verb: % at end of format string") + } + // %% acts like a real percent + nextc, _ := utf8.DecodeRuneInString(format[i+w:]) // will not match % if string is empty + if nextc != '%' { + return + } + i += w // skip the first % + } + + // Literals. + inputc := s.mustReadRune() + if fmtc != inputc { + s.UnreadRune() + return -1 + } + i += w + } + return +} + +// doScanf does the real work when scanning with a format string. +// At the moment, it handles only pointers to basic types. +func (s *ss) doScanf(format string, a []any) (numProcessed int, err error) { + defer errorHandler(&err) + end := len(format) - 1 + // We process one item per non-trivial format + for i := 0; i <= end; { + w := s.advance(format[i:]) + if w > 0 { + i += w + continue + } + // Either we failed to advance, we have a percent character, or we ran out of input. + if format[i] != '%' { + // Can't advance format. Why not? + if w < 0 { + s.errorString("input does not match format") + } + // Otherwise at EOF; "too many operands" error handled below + break + } + i++ // % is one byte + + // do we have 20 (width)? + var widPresent bool + s.maxWid, widPresent, i = parsenum(format, i, end) + if !widPresent { + s.maxWid = hugeWid + } + + c, w := utf8.DecodeRuneInString(format[i:]) + i += w + + if c != 'c' { + s.SkipSpace() + } + if c == '%' { + s.scanPercent() + continue // Do not consume an argument. + } + s.argLimit = s.limit + if f := s.count + s.maxWid; f < s.argLimit { + s.argLimit = f + } + + if numProcessed >= len(a) { // out of operands + s.errorString("too few operands for format '%" + format[i-w:] + "'") + break + } + arg := a[numProcessed] + + s.scanOne(c, arg) + numProcessed++ + s.argLimit = s.limit + } + if numProcessed < len(a) { + s.errorString("too many operands") + } + return +} diff --git a/contrib/go/_std_1.22/src/fmt/ya.make b/contrib/go/_std_1.22/src/fmt/ya.make new file mode 100644 index 0000000000..d8cb686b0d --- /dev/null +++ b/contrib/go/_std_1.22/src/fmt/ya.make @@ -0,0 +1,11 @@ +GO_LIBRARY() +IF (TRUE) + SRCS( + doc.go + errors.go + format.go + print.go + scan.go + ) +ENDIF() +END() |