+++ /dev/null
-// 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.
-
-// The testing package implements a simple regular expression library.
-// It is a reduced version of the regular expression package suitable
-// for use in tests; it avoids many dependencies.
-//
-// The syntax of the regular expressions accepted is:
-//
-// regexp:
-// concatenation { '|' concatenation }
-// concatenation:
-// { closure }
-// closure:
-// term [ '*' | '+' | '?' ]
-// term:
-// '^'
-// '$'
-// '.'
-// character
-// '[' [ '^' ] character-ranges ']'
-// '(' regexp ')'
-//
-
-package testing
-
-import (
- "utf8"
-)
-
-var debug = false
-
-// Error codes returned by failures to parse an expression.
-var (
- ErrInternal = "internal error"
- ErrUnmatchedLpar = "unmatched '('"
- ErrUnmatchedRpar = "unmatched ')'"
- ErrUnmatchedLbkt = "unmatched '['"
- ErrUnmatchedRbkt = "unmatched ']'"
- ErrBadRange = "bad range in character class"
- ErrExtraneousBackslash = "extraneous backslash"
- ErrBadClosure = "repeated closure (**, ++, etc.)"
- ErrBareClosure = "closure applies to nothing"
- ErrBadBackslash = "illegal backslash escape"
-)
-
-// An instruction executed by the NFA
-type instr interface {
- kind() int // the type of this instruction: _CHAR, _ANY, etc.
- next() instr // the instruction to execute after this one
- setNext(i instr)
- index() int
- setIndex(i int)
- print()
-}
-
-// Fields and methods common to all instructions
-type common struct {
- _next instr
- _index int
-}
-
-func (c *common) next() instr { return c._next }
-func (c *common) setNext(i instr) { c._next = i }
-func (c *common) index() int { return c._index }
-func (c *common) setIndex(i int) { c._index = i }
-
-// The representation of a compiled regular expression.
-// The public interface is entirely through methods.
-type Regexp struct {
- expr string // the original expression
- inst []instr
- start instr
- nbra int // number of brackets in expression, for subexpressions
-}
-
-const (
- _START = iota // beginning of program
- _END // end of program: success
- _BOT // '^' beginning of text
- _EOT // '$' end of text
- _CHAR // 'a' regular character
- _CHARCLASS // [a-z] character class
- _ANY // '.' any character including newline
- _NOTNL // [^\n] special case: any character but newline
- _BRA // '(' parenthesized expression
- _EBRA // ')'; end of '(' parenthesized expression
- _ALT // '|' alternation
- _NOP // do nothing; makes it easy to link without patching
-)
-
-// --- START start of program
-type _Start struct {
- common
-}
-
-func (start *_Start) kind() int { return _START }
-func (start *_Start) print() { print("start") }
-
-// --- END end of program
-type _End struct {
- common
-}
-
-func (end *_End) kind() int { return _END }
-func (end *_End) print() { print("end") }
-
-// --- BOT beginning of text
-type _Bot struct {
- common
-}
-
-func (bot *_Bot) kind() int { return _BOT }
-func (bot *_Bot) print() { print("bot") }
-
-// --- EOT end of text
-type _Eot struct {
- common
-}
-
-func (eot *_Eot) kind() int { return _EOT }
-func (eot *_Eot) print() { print("eot") }
-
-// --- CHAR a regular character
-type _Char struct {
- common
- char int
-}
-
-func (char *_Char) kind() int { return _CHAR }
-func (char *_Char) print() { print("char ", string(char.char)) }
-
-func newChar(char int) *_Char {
- c := new(_Char)
- c.char = char
- return c
-}
-
-// --- CHARCLASS [a-z]
-
-type _CharClass struct {
- common
- char int
- negate bool // is character class negated? ([^a-z])
- // stored pairwise: [a-z] is (a,z); x is (x,x):
- ranges []int
-}
-
-func (cclass *_CharClass) kind() int { return _CHARCLASS }
-
-func (cclass *_CharClass) print() {
- print("charclass")
- if cclass.negate {
- print(" (negated)")
- }
- for i := 0; i < len(cclass.ranges); i += 2 {
- l := cclass.ranges[i]
- r := cclass.ranges[i+1]
- if l == r {
- print(" [", string(l), "]")
- } else {
- print(" [", string(l), "-", string(r), "]")
- }
- }
-}
-
-func (cclass *_CharClass) addRange(a, b int) {
- // range is a through b inclusive
- cclass.ranges = append(cclass.ranges, a, b)
-}
-
-func (cclass *_CharClass) matches(c int) bool {
- for i := 0; i < len(cclass.ranges); i = i + 2 {
- min := cclass.ranges[i]
- max := cclass.ranges[i+1]
- if min <= c && c <= max {
- return !cclass.negate
- }
- }
- return cclass.negate
-}
-
-func newCharClass() *_CharClass {
- c := new(_CharClass)
- c.ranges = make([]int, 0, 20)
- return c
-}
-
-// --- ANY any character
-type _Any struct {
- common
-}
-
-func (any *_Any) kind() int { return _ANY }
-func (any *_Any) print() { print("any") }
-
-// --- NOTNL any character but newline
-type _NotNl struct {
- common
-}
-
-func (notnl *_NotNl) kind() int { return _NOTNL }
-func (notnl *_NotNl) print() { print("notnl") }
-
-// --- BRA parenthesized expression
-type _Bra struct {
- common
- n int // subexpression number
-}
-
-func (bra *_Bra) kind() int { return _BRA }
-func (bra *_Bra) print() { print("bra", bra.n) }
-
-// --- EBRA end of parenthesized expression
-type _Ebra struct {
- common
- n int // subexpression number
-}
-
-func (ebra *_Ebra) kind() int { return _EBRA }
-func (ebra *_Ebra) print() { print("ebra ", ebra.n) }
-
-// --- ALT alternation
-type _Alt struct {
- common
- left instr // other branch
-}
-
-func (alt *_Alt) kind() int { return _ALT }
-func (alt *_Alt) print() { print("alt(", alt.left.index(), ")") }
-
-// --- NOP no operation
-type _Nop struct {
- common
-}
-
-func (nop *_Nop) kind() int { return _NOP }
-func (nop *_Nop) print() { print("nop") }
-
-func (re *Regexp) add(i instr) instr {
- i.setIndex(len(re.inst))
- re.inst = append(re.inst, i)
- return i
-}
-
-type parser struct {
- re *Regexp
- nlpar int // number of unclosed lpars
- pos int
- ch int
-}
-
-func (p *parser) error(err string) {
- panic(err)
-}
-
-const endOfFile = -1
-
-func (p *parser) c() int { return p.ch }
-
-func (p *parser) nextc() int {
- if p.pos >= len(p.re.expr) {
- p.ch = endOfFile
- } else {
- c, w := utf8.DecodeRuneInString(p.re.expr[p.pos:])
- p.ch = c
- p.pos += w
- }
- return p.ch
-}
-
-func newParser(re *Regexp) *parser {
- p := new(parser)
- p.re = re
- p.nextc() // load p.ch
- return p
-}
-
-func special(c int) bool {
- s := `\.+*?()|[]^$`
- for i := 0; i < len(s); i++ {
- if c == int(s[i]) {
- return true
- }
- }
- return false
-}
-
-func specialcclass(c int) bool {
- s := `\-[]`
- for i := 0; i < len(s); i++ {
- if c == int(s[i]) {
- return true
- }
- }
- return false
-}
-
-func (p *parser) charClass() instr {
- cc := newCharClass()
- if p.c() == '^' {
- cc.negate = true
- p.nextc()
- }
- left := -1
- for {
- switch c := p.c(); c {
- case ']', endOfFile:
- if left >= 0 {
- p.error(ErrBadRange)
- }
- // Is it [^\n]?
- if cc.negate && len(cc.ranges) == 2 &&
- cc.ranges[0] == '\n' && cc.ranges[1] == '\n' {
- nl := new(_NotNl)
- p.re.add(nl)
- return nl
- }
- p.re.add(cc)
- return cc
- case '-': // do this before backslash processing
- p.error(ErrBadRange)
- case '\\':
- c = p.nextc()
- switch {
- case c == endOfFile:
- p.error(ErrExtraneousBackslash)
- case c == 'n':
- c = '\n'
- case specialcclass(c):
- // c is as delivered
- default:
- p.error(ErrBadBackslash)
- }
- fallthrough
- default:
- p.nextc()
- switch {
- case left < 0: // first of pair
- if p.c() == '-' { // range
- p.nextc()
- left = c
- } else { // single char
- cc.addRange(c, c)
- }
- case left <= c: // second of pair
- cc.addRange(left, c)
- left = -1
- default:
- p.error(ErrBadRange)
- }
- }
- }
- return nil
-}
-
-func (p *parser) term() (start, end instr) {
- switch c := p.c(); c {
- case '|', endOfFile:
- return nil, nil
- case '*', '+':
- p.error(ErrBareClosure)
- return
- case ')':
- if p.nlpar == 0 {
- p.error(ErrUnmatchedRpar)
- }
- return nil, nil
- case ']':
- p.error(ErrUnmatchedRbkt)
- case '^':
- p.nextc()
- start = p.re.add(new(_Bot))
- return start, start
- case '$':
- p.nextc()
- start = p.re.add(new(_Eot))
- return start, start
- case '.':
- p.nextc()
- start = p.re.add(new(_Any))
- return start, start
- case '[':
- p.nextc()
- start = p.charClass()
- if p.c() != ']' {
- p.error(ErrUnmatchedLbkt)
- }
- p.nextc()
- return start, start
- case '(':
- p.nextc()
- p.nlpar++
- p.re.nbra++ // increment first so first subexpr is \1
- nbra := p.re.nbra
- start, end = p.regexp()
- if p.c() != ')' {
- p.error(ErrUnmatchedLpar)
- }
- p.nlpar--
- p.nextc()
- bra := new(_Bra)
- p.re.add(bra)
- ebra := new(_Ebra)
- p.re.add(ebra)
- bra.n = nbra
- ebra.n = nbra
- if start == nil {
- if end == nil {
- p.error(ErrInternal)
- }
- start = ebra
- } else {
- end.setNext(ebra)
- }
- bra.setNext(start)
- return bra, ebra
- case '\\':
- c = p.nextc()
- switch {
- case c == endOfFile:
- p.error(ErrExtraneousBackslash)
- return
- case c == 'n':
- c = '\n'
- case special(c):
- // c is as delivered
- default:
- p.error(ErrBadBackslash)
- }
- fallthrough
- default:
- p.nextc()
- start = newChar(c)
- p.re.add(start)
- return start, start
- }
- panic("unreachable")
-}
-
-func (p *parser) closure() (start, end instr) {
- start, end = p.term()
- if start == nil {
- return
- }
- switch p.c() {
- case '*':
- // (start,end)*:
- alt := new(_Alt)
- p.re.add(alt)
- end.setNext(alt) // after end, do alt
- alt.left = start // alternate brach: return to start
- start = alt // alt becomes new (start, end)
- end = alt
- case '+':
- // (start,end)+:
- alt := new(_Alt)
- p.re.add(alt)
- end.setNext(alt) // after end, do alt
- alt.left = start // alternate brach: return to start
- end = alt // start is unchanged; end is alt
- case '?':
- // (start,end)?:
- alt := new(_Alt)
- p.re.add(alt)
- nop := new(_Nop)
- p.re.add(nop)
- alt.left = start // alternate branch is start
- alt.setNext(nop) // follow on to nop
- end.setNext(nop) // after end, go to nop
- start = alt // start is now alt
- end = nop // end is nop pointed to by both branches
- default:
- return
- }
- switch p.nextc() {
- case '*', '+', '?':
- p.error(ErrBadClosure)
- }
- return
-}
-
-func (p *parser) concatenation() (start, end instr) {
- for {
- nstart, nend := p.closure()
- switch {
- case nstart == nil: // end of this concatenation
- if start == nil { // this is the empty string
- nop := p.re.add(new(_Nop))
- return nop, nop
- }
- return
- case start == nil: // this is first element of concatenation
- start, end = nstart, nend
- default:
- end.setNext(nstart)
- end = nend
- }
- }
- panic("unreachable")
-}
-
-func (p *parser) regexp() (start, end instr) {
- start, end = p.concatenation()
- for {
- switch p.c() {
- default:
- return
- case '|':
- p.nextc()
- nstart, nend := p.concatenation()
- alt := new(_Alt)
- p.re.add(alt)
- alt.left = start
- alt.setNext(nstart)
- nop := new(_Nop)
- p.re.add(nop)
- end.setNext(nop)
- nend.setNext(nop)
- start, end = alt, nop
- }
- }
- panic("unreachable")
-}
-
-func unNop(i instr) instr {
- for i.kind() == _NOP {
- i = i.next()
- }
- return i
-}
-
-func (re *Regexp) eliminateNops() {
- for i := 0; i < len(re.inst); i++ {
- inst := re.inst[i]
- if inst.kind() == _END {
- continue
- }
- inst.setNext(unNop(inst.next()))
- if inst.kind() == _ALT {
- alt := inst.(*_Alt)
- alt.left = unNop(alt.left)
- }
- }
-}
-
-func (re *Regexp) doParse() {
- p := newParser(re)
- start := new(_Start)
- re.add(start)
- s, e := p.regexp()
- start.setNext(s)
- re.start = start
- e.setNext(re.add(new(_End)))
- re.eliminateNops()
-}
-
-// CompileRegexp parses a regular expression and returns, if successful, a Regexp
-// object that can be used to match against text.
-func CompileRegexp(str string) (regexp *Regexp, error string) {
- regexp = new(Regexp)
- // doParse will panic if there is a parse error.
- defer func() {
- if e := recover(); e != nil {
- regexp = nil
- error = e.(string) // Will re-panic if error was not a string, e.g. nil-pointer exception
- }
- }()
- regexp.expr = str
- regexp.inst = make([]instr, 0, 20)
- regexp.doParse()
- return
-}
-
-// MustCompileRegexp is like CompileRegexp but panics if the expression cannot be parsed.
-// It simplifies safe initialization of global variables holding compiled regular
-// expressions.
-func MustCompile(str string) *Regexp {
- regexp, error := CompileRegexp(str)
- if error != "" {
- panic(`regexp: compiling "` + str + `": ` + error)
- }
- return regexp
-}
-
-type state struct {
- inst instr // next instruction to execute
- match []int // pairs of bracketing submatches. 0th is start,end
-}
-
-// Append new state to to-do list. Leftmost-longest wins so avoid
-// adding a state that's already active.
-func addState(s []state, inst instr, match []int) []state {
- index := inst.index()
- l := len(s)
- pos := match[0]
- // TODO: Once the state is a vector and we can do insert, have inputs always
- // go in order correctly and this "earlier" test is never necessary,
- for i := 0; i < l; i++ {
- if s[i].inst.index() == index && // same instruction
- s[i].match[0] < pos { // earlier match already going; lefmost wins
- return s
- }
- }
- if l == cap(s) {
- s1 := make([]state, 2*l)[0:l]
- for i := 0; i < l; i++ {
- s1[i] = s[i]
- }
- s = s1
- }
- s = s[0 : l+1]
- s[l].inst = inst
- s[l].match = match
- return s
-}
-
-// Accepts either string or bytes - the logic is identical either way.
-// If bytes == nil, scan str.
-func (re *Regexp) doExecute(str string, bytes []byte, pos int) []int {
- var s [2][]state // TODO: use a vector when state values (not ptrs) can be vector elements
- s[0] = make([]state, 10)[0:0]
- s[1] = make([]state, 10)[0:0]
- in, out := 0, 1
- var final state
- found := false
- end := len(str)
- if bytes != nil {
- end = len(bytes)
- }
- for pos <= end {
- if !found {
- // prime the pump if we haven't seen a match yet
- match := make([]int, 2*(re.nbra+1))
- for i := 0; i < len(match); i++ {
- match[i] = -1 // no match seen; catches cases like "a(b)?c" on "ac"
- }
- match[0] = pos
- s[out] = addState(s[out], re.start.next(), match)
- }
- in, out = out, in // old out state is new in state
- s[out] = s[out][0:0] // clear out state
- if len(s[in]) == 0 {
- // machine has completed
- break
- }
- charwidth := 1
- c := endOfFile
- if pos < end {
- if bytes == nil {
- c, charwidth = utf8.DecodeRuneInString(str[pos:end])
- } else {
- c, charwidth = utf8.DecodeRune(bytes[pos:end])
- }
- }
- for i := 0; i < len(s[in]); i++ {
- st := s[in][i]
- switch s[in][i].inst.kind() {
- case _BOT:
- if pos == 0 {
- s[in] = addState(s[in], st.inst.next(), st.match)
- }
- case _EOT:
- if pos == end {
- s[in] = addState(s[in], st.inst.next(), st.match)
- }
- case _CHAR:
- if c == st.inst.(*_Char).char {
- s[out] = addState(s[out], st.inst.next(), st.match)
- }
- case _CHARCLASS:
- if st.inst.(*_CharClass).matches(c) {
- s[out] = addState(s[out], st.inst.next(), st.match)
- }
- case _ANY:
- if c != endOfFile {
- s[out] = addState(s[out], st.inst.next(), st.match)
- }
- case _NOTNL:
- if c != endOfFile && c != '\n' {
- s[out] = addState(s[out], st.inst.next(), st.match)
- }
- case _BRA:
- n := st.inst.(*_Bra).n
- st.match[2*n] = pos
- s[in] = addState(s[in], st.inst.next(), st.match)
- case _EBRA:
- n := st.inst.(*_Ebra).n
- st.match[2*n+1] = pos
- s[in] = addState(s[in], st.inst.next(), st.match)
- case _ALT:
- s[in] = addState(s[in], st.inst.(*_Alt).left, st.match)
- // give other branch a copy of this match vector
- s1 := make([]int, 2*(re.nbra+1))
- for i := 0; i < len(s1); i++ {
- s1[i] = st.match[i]
- }
- s[in] = addState(s[in], st.inst.next(), s1)
- case _END:
- // choose leftmost longest
- if !found || // first
- st.match[0] < final.match[0] || // leftmost
- (st.match[0] == final.match[0] && pos > final.match[1]) { // longest
- final = st
- final.match[1] = pos
- }
- found = true
- default:
- st.inst.print()
- panic("unknown instruction in execute")
- }
- }
- pos += charwidth
- }
- return final.match
-}
-
-
-// MatchString returns whether the Regexp matches the string s.
-// The return value is a boolean: true for match, false for no match.
-func (re *Regexp) MatchString(s string) bool { return len(re.doExecute(s, nil, 0)) > 0 }
-
-
-// Match returns whether the Regexp matches the byte slice b.
-// The return value is a boolean: true for match, false for no match.
-func (re *Regexp) Match(b []byte) bool { return len(re.doExecute("", b, 0)) > 0 }
-
-
-// MatchString checks whether a textual regular expression
-// matches a string. More complicated queries need
-// to use Compile and the full Regexp interface.
-func MatchString(pattern string, s string) (matched bool, error string) {
- re, err := CompileRegexp(pattern)
- if err != "" {
- return false, err
- }
- return re.MatchString(s), ""
-}
-
-
-// Match checks whether a textual regular expression
-// matches a byte slice. More complicated queries need
-// to use Compile and the full Regexp interface.
-func Match(pattern string, b []byte) (matched bool, error string) {
- re, err := CompileRegexp(pattern)
- if err != "" {
- return false, err
- }
- return re.Match(b), ""
-}
+++ /dev/null
-// 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 testing
-
-var good_re = []string{
- ``,
- `.`,
- `^.$`,
- `a`,
- `a*`,
- `a+`,
- `a?`,
- `a|b`,
- `a*|b*`,
- `(a*|b)(c*|d)`,
- `[a-z]`,
- `[a-abc-c\-\]\[]`,
- `[a-z]+`,
- `[]`,
- `[abc]`,
- `[^1234]`,
- `[^\n]`,
-}
-
-// TODO: nice to do this with a map
-type stringError struct {
- re string
- err string
-}
-
-var bad_re = []stringError{
- {`*`, ErrBareClosure},
- {`(abc`, ErrUnmatchedLpar},
- {`abc)`, ErrUnmatchedRpar},
- {`x[a-z`, ErrUnmatchedLbkt},
- {`abc]`, ErrUnmatchedRbkt},
- {`[z-a]`, ErrBadRange},
- {`abc\`, ErrExtraneousBackslash},
- {`a**`, ErrBadClosure},
- {`a*+`, ErrBadClosure},
- {`a??`, ErrBadClosure},
- {`*`, ErrBareClosure},
- {`\x`, ErrBadBackslash},
-}
-
-type vec []int
-
-type tester struct {
- re string
- text string
- match vec
-}
-
-var matches = []tester{
- {``, "", vec{0, 0}},
- {`a`, "a", vec{0, 1}},
- {`x`, "y", vec{}},
- {`b`, "abc", vec{1, 2}},
- {`.`, "a", vec{0, 1}},
- {`.*`, "abcdef", vec{0, 6}},
- {`^abcd$`, "abcd", vec{0, 4}},
- {`^bcd'`, "abcdef", vec{}},
- {`^abcd$`, "abcde", vec{}},
- {`a+`, "baaab", vec{1, 4}},
- {`a*`, "baaab", vec{0, 0}},
- {`[a-z]+`, "abcd", vec{0, 4}},
- {`[^a-z]+`, "ab1234cd", vec{2, 6}},
- {`[a\-\]z]+`, "az]-bcz", vec{0, 4}},
- {`[^\n]+`, "abcd\n", vec{0, 4}},
- {`[日本語]+`, "日本語日本語", vec{0, 18}},
- {`()`, "", vec{0, 0, 0, 0}},
- {`(a)`, "a", vec{0, 1, 0, 1}},
- {`(.)(.)`, "日a", vec{0, 4, 0, 3, 3, 4}},
- {`(.*)`, "", vec{0, 0, 0, 0}},
- {`(.*)`, "abcd", vec{0, 4, 0, 4}},
- {`(..)(..)`, "abcd", vec{0, 4, 0, 2, 2, 4}},
- {`(([^xyz]*)(d))`, "abcd", vec{0, 4, 0, 4, 0, 3, 3, 4}},
- {`((a|b|c)*(d))`, "abcd", vec{0, 4, 0, 4, 2, 3, 3, 4}},
- {`(((a|b|c)*)(d))`, "abcd", vec{0, 4, 0, 4, 0, 3, 2, 3, 3, 4}},
- {`a*(|(b))c*`, "aacc", vec{0, 4, 2, 2, -1, -1}},
-}
-
-func compileTest(t *T, expr string, error string) *Regexp {
- re, err := CompileRegexp(expr)
- if err != error {
- t.Error("compiling `", expr, "`; unexpected error: ", err)
- }
- return re
-}
-
-func TestGoodCompile(t *T) {
- for i := 0; i < len(good_re); i++ {
- compileTest(t, good_re[i], "")
- }
-}
-
-func TestBadCompile(t *T) {
- for i := 0; i < len(bad_re); i++ {
- compileTest(t, bad_re[i].re, bad_re[i].err)
- }
-}
-
-func matchTest(t *T, expr string, str string, match []int) {
- re := compileTest(t, expr, "")
- if re == nil {
- return
- }
- m := re.MatchString(str)
- if m != (len(match) > 0) {
- t.Error("MatchString failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
- }
- // now try bytes
- m = re.Match([]byte(str))
- if m != (len(match) > 0) {
- t.Error("Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
- }
-}
-
-func TestMatch(t *T) {
- for i := 0; i < len(matches); i++ {
- test := &matches[i]
- matchTest(t, test.re, test.text, test.match)
- }
-}
-
-func matchFunctionTest(t *T, expr string, str string, match []int) {
- m, err := MatchString(expr, str)
- if err == "" {
- return
- }
- if m != (len(match) > 0) {
- t.Error("function Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
- }
-}
-
-func TestMatchFunction(t *T) {
- for i := 0; i < len(matches); i++ {
- test := &matches[i]
- matchFunctionTest(t, test.re, test.text, test.match)
- }
-}