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exp/regexp/syntax: more escapes, character classes

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Still TODO: parsing optimizations

make_perl_groups.pl is copied with minimal modifications
(just to generate Go syntax instead of C++) from RE2.
Google Inc is "The RE2 Author" of that file and is one of
the Go Authors, so copyright changed to the Go Authors instead.

R=sam.thorogood, r, fvbommel, robert.hencke
CC=golang-dev
https://golang.org/cl/4612041
This commit is contained in:
Russ Cox 2011-06-14 14:30:10 -04:00
parent 340251e43d
commit 1a4681ed74
5 changed files with 1006 additions and 104 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/pkg/exp/regexp/syntax/Makefile
View File

@ -7,6 +7,7 @@ include ../../../../Make.inc
TARG=exp/regexp/syntax
GOFILES=\
parse.go\
perl_groups.go\
regexp.go\
include ../../../../Make.pkg

103
src/pkg/exp/regexp/syntax/make_perl_groups.pl Executable file
View File

@ -0,0 +1,103 @@
#!/usr/bin/perl
# Copyright 2008 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.
# Modified version of RE2's make_perl_groups.pl.
# Generate table entries giving character ranges
# for POSIX/Perl character classes. Rather than
# figure out what the definition is, it is easier to ask
# Perl about each letter from 0-128 and write down
# its answer.
@posixclasses = (
"[:alnum:]",
"[:alpha:]",
"[:ascii:]",
"[:blank:]",
"[:cntrl:]",
"[:digit:]",
"[:graph:]",
"[:lower:]",
"[:print:]",
"[:punct:]",
"[:space:]",
"[:upper:]",
"[:word:]",
"[:xdigit:]",
);
@perlclasses = (
"\\d",
"\\s",
"\\w",
);
sub ComputeClass($) {
my @ranges;
my ($class) = @_;
my $regexp = "[$class]";
my $start = -1;
for (my $i=0; $i<=129; $i++) {
if ($i == 129) { $i = 256; }
if ($i <= 128 && chr($i) =~ $regexp) {
if ($start < 0) {
$start = $i;
}
} else {
if ($start >= 0) {
push @ranges, [$start, $i-1];
}
$start = -1;
}
}
return @ranges;
}
sub PrintClass($$@) {
my ($cname, $name, @ranges) = @_;
print "var code$cname = []int{ /* $name */\n";
for (my $i=0; $i<@ranges; $i++) {
my @a = @{$ranges[$i]};
printf "\t0x%x, 0x%x,\n", $a[0], $a[1];
}
print "}\n\n";
my $n = @ranges;
$negname = $name;
if ($negname =~ /:/) {
$negname =~ s/:/:^/;
} else {
$negname =~ y/a-z/A-Z/;
}
return "\t`$name`: {+1, code$cname},\n" .
"\t`$negname`: {-1, code$cname},\n";
}
my $gen = 0;
sub PrintClasses($@) {
my ($cname, @classes) = @_;
my @entries;
foreach my $cl (@classes) {
my @ranges = ComputeClass($cl);
push @entries, PrintClass(++$gen, $cl, @ranges);
}
print "var ${cname}Group = map[string]charGroup{\n";
foreach my $e (@entries) {
print $e;
}
print "}\n";
my $count = @entries;
}
print <<EOF;
// GENERATED BY make_perl_groups.pl; DO NOT EDIT.
// make_perl_groups.pl >perl_groups.go
package syntax
EOF
PrintClasses("perl", @perlclasses);
PrintClasses("posix", @posixclasses);

744
src/pkg/exp/regexp/syntax/parse.go
View File

@ -7,6 +7,7 @@ package syntax
import (
"os"
"sort"
"strings"
"unicode"
"utf8"
)
@ -119,7 +120,7 @@ func (p *parser) op(op Op) *Regexp {
// repeat replaces the top stack element with itself repeated
// according to op.
func (p *parser) repeat(op Op, opstr string) os.Error {
func (p *parser) repeat(op Op, min, max int, flags Flags, opstr string) os.Error {
n := len(p.stack)
if n == 0 {
return &Error{ErrMissingRepeatArgument, opstr}
@ -127,6 +128,9 @@ func (p *parser) repeat(op Op, opstr string) os.Error {
sub := p.stack[n-1]
re := &Regexp{
Op: op,
Min: min,
Max: max,
Flags: flags,
}
re.Sub = re.Sub0[:1]
re.Sub[0] = sub
@ -185,14 +189,7 @@ func (p *parser) alternate() *Regexp {
return p.push(re)
}
// Parsing.
func Parse(s string, flags Flags) (*Regexp, os.Error) {
if flags&Literal != 0 {
// Trivial parser for literal string.
if err := checkUTF8(s); err != nil {
return nil, err
}
func literalRegexp(s string, flags Flags) *Regexp {
re := &Regexp{
Op: OpLiteral,
Flags: flags,
@ -206,7 +203,18 @@ func Parse(s string, flags Flags) (*Regexp, os.Error) {
}
re.Rune = append(re.Rune, c)
}
return re, nil
return re
}
// Parsing.
func Parse(s string, flags Flags) (*Regexp, os.Error) {
if flags&Literal != 0 {
// Trivial parser for literal string.
if err := checkUTF8(s); err != nil {
return nil, err
}
return literalRegexp(s, flags), nil
}
// Otherwise, must do real work.
@ -215,11 +223,15 @@ func Parse(s string, flags Flags) (*Regexp, os.Error) {
err os.Error
c int
op Op
lastRepeat string
min, max int
)
p.flags = flags
p.wholeRegexp = s
t := s
for t != "" {
repeat := ""
BigSwitch:
switch t[0] {
default:
if c, t, err = nextRune(t); err != nil {
@ -228,11 +240,11 @@ func Parse(s string, flags Flags) (*Regexp, os.Error) {
p.literal(c)
case '(':
// TODO: Actual Perl flag parsing.
if len(t) >= 3 && t[1] == '?' && t[2] == ':' {
// non-capturing paren
p.op(opLeftParen)
t = t[3:]
if p.flags&PerlX != 0 && len(t) >= 2 && t[1] == '?' {
// Flag changes and non-capturing groups.
if t, err = p.parsePerlFlags(t); err != nil {
return nil, err
}
break
}
p.numCap++
@ -283,16 +295,109 @@ func Parse(s string, flags Flags) (*Regexp, os.Error) {
case '?':
op = OpQuest
}
// TODO: greedy
if err = p.repeat(op, t[0:1]); err != nil {
repeat = t
t = t[1:]
goto Repeat
case '{':
op = OpRepeat
n, m, tt, ok := p.parseRepeat(t)
if !ok {
// If the repeat cannot be parsed, { is a literal.
p.literal('{')
t = t[1:]
break
}
repeat, t = t, tt
min, max = n, m
Repeat:
flags := p.flags
if p.flags&PerlX != 0 {
if len(t) > 0 && t[0] == '?' {
t = t[1:]
flags ^= NonGreedy
}
if lastRepeat != "" {
// In Perl it is not allowed to stack repetition operators:
// a** is a syntax error, not a doubled star, and a++ means
// something else entirely, which we don't support!
return nil, &Error{ErrInvalidRepeatOp, lastRepeat[:len(lastRepeat)-len(t)]}
}
}
if err = p.repeat(op, min, max, flags, repeat[:len(repeat)-len(t)]); err != nil {
return nil, err
}
t = t[1:]
case '{':
return nil, os.NewError("repeat not implemented")
case '\\':
return nil, os.NewError("escape not implemented")
if p.flags&PerlX != 0 && len(t) >= 2 {
switch t[1] {
case 'A':
p.op(OpBeginText)
t = t[2:]
break BigSwitch
case 'b':
p.op(OpWordBoundary)
t = t[2:]
break BigSwitch
case 'B':
p.op(OpNoWordBoundary)
t = t[2:]
break BigSwitch
case 'C':
// any byte; not supported
return nil, &Error{ErrInvalidEscape, t[:2]}
case 'Q':
// \Q ... \E: the ... is always literals
var lit string
if i := strings.Index(t, `\E`); i < 0 {
lit = t[2:]
t = ""
} else {
lit = t[2:i]
t = t[i+2:]
}
p.push(literalRegexp(lit, p.flags))
break BigSwitch
case 'z':
p.op(OpEndText)
t = t[2:]
break BigSwitch
}
}
re := &Regexp{Op: OpCharClass, Flags: p.flags}
// Look for Unicode character group like \p{Han}
if len(t) >= 2 && (t[1] == 'p' || t[1] == 'P') {
r, rest, err := p.parseUnicodeClass(t, re.Rune0[:0])
if err != nil {
return nil, err
}
if r != nil {
re.Rune = r
t = rest
// TODO: Handle FoldCase flag.
p.push(re)
break BigSwitch
}
}
// Perl character class escape.
if r, rest := p.parsePerlClassEscape(t, re.Rune0[:0]); r != nil {
re.Rune = r
t = rest
// TODO: Handle FoldCase flag.
p.push(re)
break BigSwitch
}
// TODO: Give re back to parser's pool.
// Ordinary single-character escape.
if c, t, err = p.parseEscape(t); err != nil {
return nil, err
}
p.literal(c)
}
lastRepeat = repeat
}
p.concat()
@ -309,6 +414,187 @@ func Parse(s string, flags Flags) (*Regexp, os.Error) {
return p.stack[0], nil
}
// parseRepeat parses {min} (max=min) or {min,} (max=-1) or {min,max}.
// If s is not of that form, it returns ok == false.
func (p *parser) parseRepeat(s string) (min, max int, rest string, ok bool) {
if s == "" || s[0] != '{' {
return
}
s = s[1:]
if min, s, ok = p.parseInt(s); !ok {
return
}
if s == "" {
return
}
if s[0] != ',' {
max = min
} else {
s = s[1:]
if s == "" {
return
}
if s[0] == '}' {
max = -1
} else if max, s, ok = p.parseInt(s); !ok {
return
}
}
if s == "" || s[0] != '}' {
return
}
rest = s[1:]
ok = true
return
}
// parsePerlFlags parses a Perl flag setting or non-capturing group or both,
// like (?i) or (?: or (?i:. It removes the prefix from s and updates the parse state.
// The caller must have ensured that s begins with "(?".
func (p *parser) parsePerlFlags(s string) (rest string, err os.Error) {
t := s
// Check for named captures, first introduced in Python's regexp library.
// As usual, there are three slightly different syntaxes:
//
// (?P<name>expr) the original, introduced by Python
// (?<name>expr) the .NET alteration, adopted by Perl 5.10
// (?'name'expr) another .NET alteration, adopted by Perl 5.10
//
// Perl 5.10 gave in and implemented the Python version too,
// but they claim that the last two are the preferred forms.
// PCRE and languages based on it (specifically, PHP and Ruby)
// support all three as well. EcmaScript 4 uses only the Python form.
//
// In both the open source world (via Code Search) and the
// Google source tree, (?P<expr>name) is the dominant form,
// so that's the one we implement. One is enough.
if len(t) > 4 && t[2] == 'P' && t[3] == '<' {
// Pull out name.
end := strings.IndexRune(t, '>')
if end < 0 {
if err = checkUTF8(t); err != nil {
return "", err
}
return "", &Error{ErrInvalidNamedCapture, s}
}
capture := t[:end+1] // "(?P<name>"
name := t[4:end] // "name"
if err = checkUTF8(name); err != nil {
return "", err
}
if !isValidCaptureName(name) {
return "", &Error{ErrInvalidNamedCapture, capture}
}
// Like ordinary capture, but named.
p.numCap++
re := p.op(opLeftParen)
re.Cap = p.numCap
re.Name = name
return t[end+1:], nil
}
// Non-capturing group. Might also twiddle Perl flags.
var c int
t = t[2:] // skip (?
flags := p.flags
sign := +1
sawFlag := false
Loop:
for t != "" {
if c, t, err = nextRune(t); err != nil {
return "", err
}
switch c {
default:
break Loop
// Flags.
case 'i':
flags |= FoldCase
sawFlag = true
case 'm':
flags &^= OneLine
sawFlag = true
case 's':
flags |= DotNL
sawFlag = true
case 'U':
flags |= NonGreedy
sawFlag = true
// Switch to negation.
case '-':
if sign < 0 {
break Loop
}
sign = -1
// Invert flags so that | above turn into &^ and vice versa.
// We'll invert flags again before using it below.
flags = ^flags
sawFlag = false
// End of flags, starting group or not.
case ':', ')':
if sign < 0 {
if !sawFlag {
break Loop
}
flags = ^flags
}
if c == ':' {
// Open new group
p.op(opLeftParen)
}
p.flags = flags
return t, nil
}
}
return "", &Error{ErrInvalidPerlOp, s[:len(s)-len(t)]}
}
// isValidCaptureName reports whether name
// is a valid capture name: [A-Za-z0-9_]+.
// PCRE limits names to 32 bytes.
// Python rejects names starting with digits.
// We don't enforce either of those.
func isValidCaptureName(name string) bool {
if name == "" {
return false
}
for _, c := range name {
if c != '_' && !isalnum(c) {
return false
}
}
return true
}
// parseInt parses a decimal integer.
func (p *parser) parseInt(s string) (n int, rest string, ok bool) {
if s == "" || s[0] < '0' || '9' < s[0] {
return
}
// Disallow leading zeros.
if len(s) >= 2 && s[0] == '0' && '0' <= s[1] && s[1] <= '9' {
return
}
for s != "" && '0' <= s[0] && s[0] <= '9' {
// Avoid overflow.
if n >= 1e8 {
return
}
n = n*10 + int(s[0]) - '0'
s = s[1:]
}
rest = s
ok = true
return
}
// parseVerticalBar handles a | in the input.
func (p *parser) parseVerticalBar() os.Error {
p.concat()
@ -371,6 +657,121 @@ func (p *parser) parseRightParen() os.Error {
return nil
}
// parseEscape parses an escape sequence at the beginning of s
// and returns the rune.
func (p *parser) parseEscape(s string) (r int, rest string, err os.Error) {
t := s[1:]
if t == "" {
return 0, "", &Error{ErrTrailingBackslash, ""}
}
c, t, err := nextRune(t)
if err != nil {
return 0, "", err
}
Switch:
switch c {
default:
if c < utf8.RuneSelf && !isalnum(c) {
// Escaped non-word characters are always themselves.
// PCRE is not quite so rigorous: it accepts things like
// \q, but we don't. We once rejected \_, but too many
// programs and people insist on using it, so allow \_.
return c, t, nil
}
// Octal escapes.
case '1', '2', '3', '4', '5', '6', '7':
// Single non-zero digit is a backreference; not supported
if t == "" || t[0] < '0' || t[0] > '7' {
break
}
fallthrough
case '0':
// Consume up to three octal digits; already have one.
r = c - '0'
for i := 1; i < 3; i++ {
if t == "" || t[0] < '0' || t[0] > '7' {
break
}
r = r*8 + int(t[0]) - '0'
t = t[1:]
}
return r, t, nil
// Hexadecimal escapes.
case 'x':
if t == "" {
break
}
if c, t, err = nextRune(t); err != nil {
return 0, "", err
}
if c == '{' {
// Any number of digits in braces.
// Perl accepts any text at all; it ignores all text
// after the first non-hex digit. We require only hex digits,
// and at least one.
nhex := 0
r = 0
for {
if t == "" {
break Switch
}
if c, t, err = nextRune(t); err != nil {
return 0, "", err
}
if c == '}' {
break
}
v := unhex(c)
if v < 0 {
break Switch
}
r = r*16 + v
if r > unicode.MaxRune {
break Switch
}
}
if nhex == 0 {
break Switch
}
return r, t, nil
}
// Easy case: two hex digits.
x := unhex(c)
if c, t, err = nextRune(t); err != nil {
return 0, "", err
}
y := unhex(c)
if x < 0 || y < 0 {
break
}
return x*16 + y, t, nil
// C escapes. There is no case 'b', to avoid misparsing
// the Perl word-boundary \b as the C backspace \b
// when in POSIX mode. In Perl, /\b/ means word-boundary
// but /[\b]/ means backspace. We don't support that.
// If you want a backspace, embed a literal backspace
// character or use \x08.
case 'a':
return '\a', t, err
case 'f':
return '\f', t, err
case 'n':
return '\n', t, err
case 'r':
return '\r', t, err
case 't':
return '\t', t, err
case 'v':
return '\v', t, err
}
return 0, "", &Error{ErrInvalidEscape, s[:len(s)-len(t)]}
}
// parseClassChar parses a character class character at the beginning of s
// and returns it.
func (p *parser) parseClassChar(s, wholeClass string) (r int, rest string, err os.Error) {
@ -378,11 +779,133 @@ func (p *parser) parseClassChar(s, wholeClass string) (r int, rest string, err o
return 0, "", &Error{Code: ErrMissingBracket, Expr: wholeClass}
}
// TODO: Escapes
// Allow regular escape sequences even though
// many need not be escaped in this context.
if s[0] == '\\' {
return p.parseEscape(s)
}
return nextRune(s)
}
type charGroup struct {
sign int
class []int
}
// parsePerlClassEscape parses a leading Perl character class escape like \d
// from the beginning of s. If one is present, it appends the characters to r
// and returns the new slice r and the remainder of the string.
func (p *parser) parsePerlClassEscape(s string, r []int) (out []int, rest string) {
if p.flags&PerlX == 0 || len(s) < 2 || s[0] != '\\' {
return
}
g := perlGroup[s[0:2]]
if g.sign == 0 {
return
}
if g.sign < 0 {
r = appendNegatedClass(r, g.class)
} else {
r = appendClass(r, g.class)
}
return r, s[2:]
}
// parseNamedClass parses a leading POSIX named character class like [:alnum:]
// from the beginning of s. If one is present, it appends the characters to r
// and returns the new slice r and the remainder of the string.
func (p *parser) parseNamedClass(s string, r []int) (out []int, rest string, err os.Error) {
if len(s) < 2 || s[0] != '[' || s[1] != ':' {
return
}
i := strings.Index(s[2:], ":]")
if i < 0 {
return
}
i += 2
name, s := s[0:i+2], s[i+2:]
g := posixGroup[name]
if g.sign == 0 {
return nil, "", &Error{ErrInvalidCharRange, name}
}
if g.sign < 0 {
r = appendNegatedClass(r, g.class)
} else {
r = appendClass(r, g.class)
}
return r, s, nil
}
// unicodeTable returns the unicode.RangeTable identified by name.
func unicodeTable(name string) *unicode.RangeTable {
if t := unicode.Categories[name]; t != nil {
return t
}
if t := unicode.Scripts[name]; t != nil {
return t
}
return nil
}
// parseUnicodeClass parses a leading Unicode character class like \p{Han}
// from the beginning of s. If one is present, it appends the characters to r
// and returns the new slice r and the remainder of the string.
func (p *parser) parseUnicodeClass(s string, r []int) (out []int, rest string, err os.Error) {
if p.flags&UnicodeGroups == 0 || len(s) < 2 || s[0] != '\\' || s[1] != 'p' && s[1] != 'P' {
return
}
// Committed to parse or return error.
sign := +1
if s[1] == 'P' {
sign = -1
}
t := s[2:]
c, t, err := nextRune(t)
if err != nil {
return
}
var seq, name string
if c != '{' {
// Single-letter name.
seq = s[:len(s)-len(t)]
name = seq[2:]
} else {
// Name is in braces.
end := strings.IndexRune(s, '}')
if end < 0 {
if err = checkUTF8(s); err != nil {
return
}
return nil, "", &Error{ErrInvalidCharRange, s}
}
seq, t = s[:end+1], s[end+1:]
name = s[3:end]
if err = checkUTF8(name); err != nil {
return
}
}
// Group can have leading negation too. \p{^Han} == \P{Han}, \P{^Han} == \p{Han}.
if name != "" && name[0] == '^' {
sign = -sign
name = name[1:]
}
tab := unicodeTable(name)
if tab == nil {
return nil, "", &Error{ErrInvalidCharRange, seq}
}
if sign > 0 {
r = appendTable(r, tab)
} else {
r = appendNegatedTable(r, tab)
}
return r, t, nil
}
// parseClass parses a character class at the beginning of s
// and pushes it onto the parse stack.
func (p *parser) parseClass(s string) (rest string, err os.Error) {
@ -413,9 +936,33 @@ func (p *parser) parseClass(s string) (rest string, err os.Error) {
}
first = false
// TODO: Look for [:alnum:]
// TODO: Look for Unicode group.
// TODO: Look for Perl group.
// Look for POSIX [:alnum:] etc.
if len(t) > 2 && t[0] == '[' && t[1] == ':' {
nclass, nt, err := p.parseNamedClass(t, class)
if err != nil {
return "", err
}
if nclass != nil {
class, t = nclass, nt
continue
}
}
// Look for Unicode character group like \p{Han}.
nclass, nt, err := p.parseUnicodeClass(t, class)
if err != nil {
return "", err
}
if nclass != nil {
class, t = nclass, nt
continue
}
// Look for Perl character class symbols (extension).
if nclass, nt := p.parsePerlClassEscape(t, class); nclass != nil {
class, t = nclass, nt
continue
}
// Single character or simple range.
rng := t
@ -435,25 +982,12 @@ func (p *parser) parseClass(s string) (rest string, err os.Error) {
return "", &Error{Code: ErrInvalidCharRange, Expr: rng}
}
}
// Expand last range if overlaps or abuts.
if n := len(class); n > 0 {
clo, chi := class[n-2], class[n-1]
if lo <= chi+1 && clo <= hi+1 {
if lo < clo {
class[n-2] = lo
}
if hi > chi {
class[n-1] = hi
}
continue
}
}
class = append(class, lo, hi)
class = appendRange(class, lo, hi)
}
t = t[1:] // chop ]
// TODO: Handle FoldCase flag.
// Use &re.Rune instead of &class to avoid allocation.
re.Rune = class
class = cleanClass(&re.Rune)
@ -492,6 +1026,117 @@ func cleanClass(rp *[]int) []int {
return r[:w]
}
// appendRange returns the result of appending the range lo-hi to the class r.
func appendRange(r []int, lo, hi int) []int {
// Expand last range if overlaps or abuts.
if n := len(r); n > 0 {
rlo, rhi := r[n-2], r[n-1]
if lo <= rhi+1 && rlo <= hi+1 {
if lo < rlo {
r[n-2] = lo
}
if hi > rhi {
r[n-1] = hi
}
return r
}
}
return append(r, lo, hi)
}
// appendClass returns the result of appending the class x to the class r.
// It assume x is clean.
func appendClass(r []int, x []int) []int {
for i := 0; i < len(x); i += 2 {
r = appendRange(r, x[i], x[i+1])
}
return r
}
// appendNegatedClass returns the result of appending the negation of the class x to the class r.
// It assumes x is clean.
func appendNegatedClass(r []int, x []int) []int {
nextLo := 0
for i := 0; i < len(x); i += 2 {
lo, hi := x[i], x[i+1]
if nextLo <= lo-1 {
r = appendRange(r, nextLo, lo-1)
}
nextLo = hi + 1
}
if nextLo <= unicode.MaxRune {
r = appendRange(r, nextLo, unicode.MaxRune)
}
return r
}
// appendTable returns the result of appending x to the class r.
func appendTable(r []int, x *unicode.RangeTable) []int {
for _, xr := range x.R16 {
lo, hi, stride := int(xr.Lo), int(xr.Hi), int(xr.Stride)
if stride == 1 {
r = appendRange(r, lo, hi)
continue
}
for c := lo; c <= hi; c += stride {
r = appendRange(r, c, c)
}
}
for _, xr := range x.R32 {
lo, hi, stride := int(xr.Lo), int(xr.Hi), int(xr.Stride)
if stride == 1 {
r = appendRange(r, lo, hi)
continue
}
for c := lo; c <= hi; c += stride {
r = appendRange(r, c, c)
}
}
return r
}
// appendNegatedTable returns the result of appending the negation of x to the class r.
func appendNegatedTable(r []int, x *unicode.RangeTable) []int {
nextLo := 0 // lo end of next class to add
for _, xr := range x.R16 {
lo, hi, stride := int(xr.Lo), int(xr.Hi), int(xr.Stride)
if stride == 1 {
if nextLo <= lo-1 {
r = appendRange(r, nextLo, lo-1)
}
nextLo = hi + 1
continue
}
for c := lo; c <= hi; c += stride {
if nextLo <= c-1 {
r = appendRange(r, nextLo, c-1)
}
nextLo = c + 1
}
}
for _, xr := range x.R32 {
lo, hi, stride := int(xr.Lo), int(xr.Hi), int(xr.Stride)
if stride == 1 {
if nextLo <= lo-1 {
r = appendRange(r, nextLo, lo-1)
}
nextLo = hi + 1
continue
}
for c := lo; c <= hi; c += stride {
if nextLo <= c-1 {
r = appendRange(r, nextLo, c-1)
}
nextLo = c + 1
}
}
if nextLo <= unicode.MaxRune {
r = appendRange(r, nextLo, unicode.MaxRune)
}
return r
}
// negateClass overwrites r and returns r's negation.
// It assumes the class r is already clean.
func negateClass(r []int) []int {
@ -559,3 +1204,20 @@ func nextRune(s string) (c int, t string, err os.Error) {
}
return c, s[size:], nil
}
func isalnum(c int) bool {
return '0' <= c && c <= '9' || 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'
}
func unhex(c int) int {
if '0' <= c && c <= '9' {
return c - '0'
}
if 'a' <= c && c <= 'f' {
return c - 'a' + 10
}
if 'A' <= c && c <= 'F' {
return c - 'A' + 10
}
return -1
}

112
src/pkg/exp/regexp/syntax/parse_test.go
View File

@ -32,68 +32,74 @@ var parseTests = []struct {
{"a*", "star{lit{a}}"},
{"a+", "plus{lit{a}}"},
{"a?", "que{lit{a}}"},
// { "a{2}", "rep{2,2 lit{a}}" },
// { "a{2,3}", "rep{2,3 lit{a}}" },
// { "a{2,}", "rep{2,-1 lit{a}}" },
// { "a*?", "nstar{lit{a}}" },
// { "a+?", "nplus{lit{a}}" },
// { "a??", "nque{lit{a}}" },
// { "a{2}?", "nrep{2,2 lit{a}}" },
// { "a{2,3}?", "nrep{2,3 lit{a}}" },
// { "a{2,}?", "nrep{2,-1 lit{a}}" },
{"a{2}", "rep{2,2 lit{a}}"},
{"a{2,3}", "rep{2,3 lit{a}}"},
{"a{2,}", "rep{2,-1 lit{a}}"},
{"a*?", "nstar{lit{a}}"},
{"a+?", "nplus{lit{a}}"},
{"a??", "nque{lit{a}}"},
{"a{2}?", "nrep{2,2 lit{a}}"},
{"a{2,3}?", "nrep{2,3 lit{a}}"},
{"a{2,}?", "nrep{2,-1 lit{a}}"},
{"", "emp{}"},
// { "|", "emp{}" }, // alt{emp{}emp{}} but got factored
// { "|", "alt{emp{}emp{}}" },
{"|", "alt{emp{}emp{}}"},
{"|x|", "alt{emp{}lit{x}emp{}}"},
{".", "dot{}"},
{"^", "bol{}"},
{"$", "eol{}"},
// { "\\|", "lit{|}" },
// { "\\(", "lit{(}" },
// { "\\)", "lit{)}" },
// { "\\*", "lit{*}" },
// { "\\+", "lit{+}" },
// { "\\?", "lit{?}" },
// { "{", "lit{{}" },
{"\\|", "lit{|}"},
{"\\(", "lit{(}"},
{"\\)", "lit{)}"},
{"\\*", "lit{*}"},
{"\\+", "lit{+}"},
{"\\?", "lit{?}"},
{"{", "lit{{}"},
{"}", "lit{}}"},
// { "\\.", "lit{.}" },
// { "\\^", "lit{^}" },
// { "\\$", "lit{$}" },
// { "\\\\", "lit{\\}" },
{"\\.", "lit{.}"},
{"\\^", "lit{^}"},
{"\\$", "lit{$}"},
{"\\\\", "lit{\\}"},
{"[ace]", "cc{0x61 0x63 0x65}"},
{"[abc]", "cc{0x61-0x63}"},
{"[a-z]", "cc{0x61-0x7a}"},
// { "[a]", "lit{a}" },
{"[a]", "cc{0x61}"},
// { "\\-", "lit{-}" },
{"\\-", "lit{-}"},
{"-", "lit{-}"},
// { "\\_", "lit{_}" },
{"\\_", "lit{_}"},
// Posix and Perl extensions
// { "[[:lower:]]", "cc{0x61-0x7a}" },
// { "[a-z]", "cc{0x61-0x7a}" },
// { "[^[:lower:]]", "cc{0x0-0x60 0x7b-0x10ffff}" },
// { "[[:^lower:]]", "cc{0x0-0x60 0x7b-0x10ffff}" },
{"[[:lower:]]", "cc{0x61-0x7a}"},
{"[a-z]", "cc{0x61-0x7a}"},
{"[^[:lower:]]", "cc{0x0-0x60 0x7b-0x10ffff}"},
{"[[:^lower:]]", "cc{0x0-0x60 0x7b-0x10ffff}"},
// { "(?i)[[:lower:]]", "cc{0x41-0x5a 0x61-0x7a 0x17f 0x212a}" },
// { "(?i)[a-z]", "cc{0x41-0x5a 0x61-0x7a 0x17f 0x212a}" },
// { "(?i)[^[:lower:]]", "cc{0x0-0x40 0x5b-0x60 0x7b-0x17e 0x180-0x2129 0x212b-0x10ffff}" },
// { "(?i)[[:^lower:]]", "cc{0x0-0x40 0x5b-0x60 0x7b-0x17e 0x180-0x2129 0x212b-0x10ffff}" },
// { "\\d", "cc{0x30-0x39}" },
// { "\\D", "cc{0x0-0x2f 0x3a-0x10ffff}" },
// { "\\s", "cc{0x9-0xa 0xc-0xd 0x20}" },
// { "\\S", "cc{0x0-0x8 0xb 0xe-0x1f 0x21-0x10ffff}" },
// { "\\w", "cc{0x30-0x39 0x41-0x5a 0x5f 0x61-0x7a}" },
// { "\\W", "cc{0x0-0x2f 0x3a-0x40 0x5b-0x5e 0x60 0x7b-0x10ffff}" },
{"\\d", "cc{0x30-0x39}"},
{"\\D", "cc{0x0-0x2f 0x3a-0x10ffff}"},
{"\\s", "cc{0x9-0xa 0xc-0xd 0x20}"},
{"\\S", "cc{0x0-0x8 0xb 0xe-0x1f 0x21-0x10ffff}"},
{"\\w", "cc{0x30-0x39 0x41-0x5a 0x5f 0x61-0x7a}"},
{"\\W", "cc{0x0-0x2f 0x3a-0x40 0x5b-0x5e 0x60 0x7b-0x10ffff}"},
// { "(?i)\\w", "cc{0x30-0x39 0x41-0x5a 0x5f 0x61-0x7a 0x17f 0x212a}" },
// { "(?i)\\W", "cc{0x0-0x2f 0x3a-0x40 0x5b-0x5e 0x60 0x7b-0x17e 0x180-0x2129 0x212b-0x10ffff}" },
// { "[^\\\\]", "cc{0x0-0x5b 0x5d-0x10ffff}" },
{"[^\\\\]", "cc{0x0-0x5b 0x5d-0x10ffff}"},
// { "\\C", "byte{}" },
// Unicode, negatives, and a double negative.
// { "\\p{Braille}", "cc{0x2800-0x28ff}" },
// { "\\P{Braille}", "cc{0x0-0x27ff 0x2900-0x10ffff}" },
// { "\\p{^Braille}", "cc{0x0-0x27ff 0x2900-0x10ffff}" },
// { "\\P{^Braille}", "cc{0x2800-0x28ff}" },
{"\\p{Braille}", "cc{0x2800-0x28ff}"},
{"\\P{Braille}", "cc{0x0-0x27ff 0x2900-0x10ffff}"},
{"\\p{^Braille}", "cc{0x0-0x27ff 0x2900-0x10ffff}"},
{"\\P{^Braille}", "cc{0x2800-0x28ff}"},
{"\\pZ", "cc{0x20 0xa0 0x1680 0x180e 0x2000-0x200a 0x2028-0x2029 0x202f 0x205f 0x3000}"},
{"[\\p{Braille}]", "cc{0x2800-0x28ff}"},
{"[\\P{Braille}]", "cc{0x0-0x27ff 0x2900-0x10ffff}"},
{"[\\p{^Braille}]", "cc{0x0-0x27ff 0x2900-0x10ffff}"},
{"[\\P{^Braille}]", "cc{0x2800-0x28ff}"},
{"[\\pZ]", "cc{0x20 0xa0 0x1680 0x180e 0x2000-0x200a 0x2028-0x2029 0x202f 0x205f 0x3000}"},
// More interesting regular expressions.
// { "a{,2}", "str{a{,2}}" },
@ -101,7 +107,7 @@ var parseTests = []struct {
{"[a-zABC]", "cc{0x41-0x43 0x61-0x7a}"},
{"[^a]", "cc{0x0-0x60 0x62-0x10ffff}"},
{"[\xce\xb1-\xce\xb5\xe2\x98\xba]", "cc{0x3b1-0x3b5 0x263a}"}, // utf-8
// { "a*{", "cat{star{lit{a}}lit{{}}" },
{"a*{", "cat{star{lit{a}}lit{{}}"},
// Test precedences
// { "(?:ab)*", "star{str{ab}}" },
@ -114,30 +120,30 @@ var parseTests = []struct {
{"a(b|c)d", "cat{lit{a}cap{alt{lit{b}lit{c}}}lit{d}}"},
// Test flattening.
// { "(?:a)", "lit{a}" },
{"(?:a)", "lit{a}"},
// { "(?:ab)(?:cd)", "str{abcd}" },
// { "(?:a|b)|(?:c|d)", "cc{0x61-0x64}" },
// { "a|.", "dot{}" },
// { ".|a", "dot{}" },
// Test Perl quoted literals
// { "\\Q+|*?{[\\E", "str{+|*?{[}" },
// { "\\Q+\\E+", "plus{lit{+}}" },
// { "\\Q\\\\E", "lit{\\}" },
// { "\\Q\\\\\\E", "str{\\\\}" },
{"\\Q+|*?{[\\E", "str{+|*?{[}"},
{"\\Q+\\E+", "plus{lit{+}}"},
{"\\Q\\\\E", "lit{\\}"},
{"\\Q\\\\\\E", "str{\\\\}"},
// Test Perl \A and \z
// { "(?m)^", "bol{}" },
// { "(?m)$", "eol{}" },
// { "(?-m)^", "bot{}" },
// { "(?-m)$", "eot{}" },
// { "(?m)\\A", "bot{}" },
// { "(?m)\\z", "eot{\\z}" },
// { "(?-m)\\A", "bot{}" },
// { "(?-m)\\z", "eot{\\z}" },
{"(?m)^", "bol{}"},
{"(?m)$", "eol{}"},
{"(?-m)^", "bot{}"},
{"(?-m)$", "eot{}"},
{"(?m)\\A", "bot{}"},
{"(?m)\\z", "eot{\\z}"},
{"(?-m)\\A", "bot{}"},
{"(?-m)\\z", "eot{\\z}"},
// Test named captures
// { "(?P<name>a)", "cap{name:lit{a}}" },
{"(?P<name>a)", "cap{name:lit{a}}"},
// Case-folded literals
// { "[Aa]", "litfold{a}" },

130
src/pkg/exp/regexp/syntax/perl_groups.go Normal file
View File

@ -0,0 +1,130 @@
// GENERATED BY make_perl_groups.pl; DO NOT EDIT.
// make_perl_groups.pl >perl_groups.go
package syntax
var code1 = []int{ /* \d */
0x30, 0x39,
}
var code2 = []int{ /* \s */
0x9, 0xa,
0xc, 0xd,
0x20, 0x20,
}
var code3 = []int{ /* \w */
0x30, 0x39,
0x41, 0x5a,
0x5f, 0x5f,
0x61, 0x7a,
}
var perlGroup = map[string]charGroup{
`\d`: {+1, code1},
`\D`: {-1, code1},
`\s`: {+1, code2},
`\S`: {-1, code2},
`\w`: {+1, code3},
`\W`: {-1, code3},
}
var code4 = []int{ /* [:alnum:] */
0x30, 0x39,
0x41, 0x5a,
0x61, 0x7a,
}
var code5 = []int{ /* [:alpha:] */
0x41, 0x5a,
0x61, 0x7a,
}
var code6 = []int{ /* [:ascii:] */
0x0, 0x7f,
}
var code7 = []int{ /* [:blank:] */
0x9, 0x9,
0x20, 0x20,
}
var code8 = []int{ /* [:cntrl:] */
0x0, 0x1f,
0x7f, 0x7f,
}
var code9 = []int{ /* [:digit:] */
0x30, 0x39,
}
var code10 = []int{ /* [:graph:] */
0x21, 0x7e,
}
var code11 = []int{ /* [:lower:] */
0x61, 0x7a,
}
var code12 = []int{ /* [:print:] */
0x20, 0x7e,
}
var code13 = []int{ /* [:punct:] */
0x21, 0x2f,
0x3a, 0x40,
0x5b, 0x60,
0x7b, 0x7e,
}
var code14 = []int{ /* [:space:] */
0x9, 0xd,
0x20, 0x20,
}
var code15 = []int{ /* [:upper:] */
0x41, 0x5a,
}
var code16 = []int{ /* [:word:] */
0x30, 0x39,
0x41, 0x5a,
0x5f, 0x5f,
0x61, 0x7a,
}
var code17 = []int{ /* [:xdigit:] */
0x30, 0x39,
0x41, 0x46,
0x61, 0x66,
}
var posixGroup = map[string]charGroup{
`[:alnum:]`: {+1, code4},
`[:^alnum:]`: {-1, code4},
`[:alpha:]`: {+1, code5},
`[:^alpha:]`: {-1, code5},
`[:ascii:]`: {+1, code6},
`[:^ascii:]`: {-1, code6},
`[:blank:]`: {+1, code7},
`[:^blank:]`: {-1, code7},
`[:cntrl:]`: {+1, code8},
`[:^cntrl:]`: {-1, code8},
`[:digit:]`: {+1, code9},
`[:^digit:]`: {-1, code9},
`[:graph:]`: {+1, code10},
`[:^graph:]`: {-1, code10},
`[:lower:]`: {+1, code11},
`[:^lower:]`: {-1, code11},
`[:print:]`: {+1, code12},
`[:^print:]`: {-1, code12},
`[:punct:]`: {+1, code13},
`[:^punct:]`: {-1, code13},
`[:space:]`: {+1, code14},
`[:^space:]`: {-1, code14},
`[:upper:]`: {+1, code15},
`[:^upper:]`: {-1, code15},
`[:word:]`: {+1, code16},
`[:^word:]`: {-1, code16},
`[:xdigit:]`: {+1, code17},
`[:^xdigit:]`: {-1, code17},
}