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path: root/src/pkg/exp/datafmt/parser.go
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Diffstat (limited to 'src/pkg/exp/datafmt/parser.go')
-rw-r--r--src/pkg/exp/datafmt/parser.go386
1 files changed, 0 insertions, 386 deletions
diff --git a/src/pkg/exp/datafmt/parser.go b/src/pkg/exp/datafmt/parser.go
deleted file mode 100644
index 7dedb531a5..0000000000
--- a/src/pkg/exp/datafmt/parser.go
+++ /dev/null
@@ -1,386 +0,0 @@
-// 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 datafmt
-
-import (
- "container/vector"
- "go/scanner"
- "go/token"
- "os"
- "strconv"
- "strings"
-)
-
-// ----------------------------------------------------------------------------
-// Parsing
-
-type parser struct {
- scanner.ErrorVector
- scanner scanner.Scanner
- file *token.File
- pos token.Pos // token position
- tok token.Token // one token look-ahead
- lit string // token literal
-
- packs map[string]string // PackageName -> ImportPath
- rules map[string]expr // RuleName -> Expression
-}
-
-
-func (p *parser) next() {
- p.pos, p.tok, p.lit = p.scanner.Scan()
- switch p.tok {
- case token.CHAN, token.FUNC, token.INTERFACE, token.MAP, token.STRUCT:
- // Go keywords for composite types are type names
- // returned by reflect. Accept them as identifiers.
- p.tok = token.IDENT // p.lit is already set correctly
- }
-}
-
-
-func (p *parser) init(fset *token.FileSet, filename string, src []byte) {
- p.ErrorVector.Reset()
- p.file = fset.AddFile(filename, fset.Base(), len(src))
- p.scanner.Init(p.file, src, p, scanner.AllowIllegalChars) // return '@' as token.ILLEGAL w/o error message
- p.next() // initializes pos, tok, lit
- p.packs = make(map[string]string)
- p.rules = make(map[string]expr)
-}
-
-
-func (p *parser) error(pos token.Pos, msg string) {
- p.Error(p.file.Position(pos), msg)
-}
-
-
-func (p *parser) errorExpected(pos token.Pos, msg string) {
- msg = "expected " + msg
- if pos == p.pos {
- // the error happened at the current position;
- // make the error message more specific
- msg += ", found '" + p.tok.String() + "'"
- if p.tok.IsLiteral() {
- msg += " " + p.lit
- }
- }
- p.error(pos, msg)
-}
-
-
-func (p *parser) expect(tok token.Token) token.Pos {
- pos := p.pos
- if p.tok != tok {
- p.errorExpected(pos, "'"+tok.String()+"'")
- }
- p.next() // make progress in any case
- return pos
-}
-
-
-func (p *parser) parseIdentifier() string {
- name := p.lit
- p.expect(token.IDENT)
- return name
-}
-
-
-func (p *parser) parseTypeName() (string, bool) {
- pos := p.pos
- name, isIdent := p.parseIdentifier(), true
- if p.tok == token.PERIOD {
- // got a package name, lookup package
- if importPath, found := p.packs[name]; found {
- name = importPath
- } else {
- p.error(pos, "package not declared: "+name)
- }
- p.next()
- name, isIdent = name+"."+p.parseIdentifier(), false
- }
- return name, isIdent
-}
-
-
-// Parses a rule name and returns it. If the rule name is
-// a package-qualified type name, the package name is resolved.
-// The 2nd result value is true iff the rule name consists of a
-// single identifier only (and thus could be a package name).
-//
-func (p *parser) parseRuleName() (string, bool) {
- name, isIdent := "", false
- switch p.tok {
- case token.IDENT:
- name, isIdent = p.parseTypeName()
- case token.DEFAULT:
- name = "default"
- p.next()
- case token.QUO:
- name = "/"
- p.next()
- default:
- p.errorExpected(p.pos, "rule name")
- p.next() // make progress in any case
- }
- return name, isIdent
-}
-
-
-func (p *parser) parseString() string {
- s := ""
- if p.tok == token.STRING {
- s, _ = strconv.Unquote(p.lit)
- // Unquote may fail with an error, but only if the scanner found
- // an illegal string in the first place. In this case the error
- // has already been reported.
- p.next()
- return s
- } else {
- p.expect(token.STRING)
- }
- return s
-}
-
-
-func (p *parser) parseLiteral() literal {
- s := []byte(p.parseString())
-
- // A string literal may contain %-format specifiers. To simplify
- // and speed up printing of the literal, split it into segments
- // that start with "%" possibly followed by a last segment that
- // starts with some other character.
- var list vector.Vector
- i0 := 0
- for i := 0; i < len(s); i++ {
- if s[i] == '%' && i+1 < len(s) {
- // the next segment starts with a % format
- if i0 < i {
- // the current segment is not empty, split it off
- list.Push(s[i0:i])
- i0 = i
- }
- i++ // skip %; let loop skip over char after %
- }
- }
- // the final segment may start with any character
- // (it is empty iff the string is empty)
- list.Push(s[i0:])
-
- // convert list into a literal
- lit := make(literal, list.Len())
- for i := 0; i < list.Len(); i++ {
- lit[i] = list.At(i).([]byte)
- }
-
- return lit
-}
-
-
-func (p *parser) parseField() expr {
- var fname string
- switch p.tok {
- case token.ILLEGAL:
- if p.lit != "@" {
- return nil
- }
- fname = "@"
- p.next()
- case token.MUL:
- fname = "*"
- p.next()
- case token.IDENT:
- fname = p.parseIdentifier()
- default:
- return nil
- }
-
- var ruleName string
- if p.tok == token.COLON {
- p.next()
- ruleName, _ = p.parseRuleName()
- }
-
- return &field{fname, ruleName}
-}
-
-
-func (p *parser) parseOperand() (x expr) {
- switch p.tok {
- case token.STRING:
- x = p.parseLiteral()
-
- case token.LPAREN:
- p.next()
- x = p.parseExpression()
- if p.tok == token.SHR {
- p.next()
- x = &group{x, p.parseExpression()}
- }
- p.expect(token.RPAREN)
-
- case token.LBRACK:
- p.next()
- x = &option{p.parseExpression()}
- p.expect(token.RBRACK)
-
- case token.LBRACE:
- p.next()
- x = p.parseExpression()
- var div expr
- if p.tok == token.QUO {
- p.next()
- div = p.parseExpression()
- }
- x = &repetition{x, div}
- p.expect(token.RBRACE)
-
- default:
- x = p.parseField() // may be nil
- }
-
- return x
-}
-
-
-func (p *parser) parseSequence() expr {
- var list vector.Vector
-
- for x := p.parseOperand(); x != nil; x = p.parseOperand() {
- list.Push(x)
- }
-
- // no need for a sequence if list.Len() < 2
- switch list.Len() {
- case 0:
- return nil
- case 1:
- return list.At(0).(expr)
- }
-
- // convert list into a sequence
- seq := make(sequence, list.Len())
- for i := 0; i < list.Len(); i++ {
- seq[i] = list.At(i).(expr)
- }
- return seq
-}
-
-
-func (p *parser) parseExpression() expr {
- var list vector.Vector
-
- for {
- x := p.parseSequence()
- if x != nil {
- list.Push(x)
- }
- if p.tok != token.OR {
- break
- }
- p.next()
- }
-
- // no need for an alternatives if list.Len() < 2
- switch list.Len() {
- case 0:
- return nil
- case 1:
- return list.At(0).(expr)
- }
-
- // convert list into a alternatives
- alt := make(alternatives, list.Len())
- for i := 0; i < list.Len(); i++ {
- alt[i] = list.At(i).(expr)
- }
- return alt
-}
-
-
-func (p *parser) parseFormat() {
- for p.tok != token.EOF {
- pos := p.pos
-
- name, isIdent := p.parseRuleName()
- switch p.tok {
- case token.STRING:
- // package declaration
- importPath := p.parseString()
-
- // add package declaration
- if !isIdent {
- p.error(pos, "illegal package name: "+name)
- } else if _, found := p.packs[name]; !found {
- p.packs[name] = importPath
- } else {
- p.error(pos, "package already declared: "+name)
- }
-
- case token.ASSIGN:
- // format rule
- p.next()
- x := p.parseExpression()
-
- // add rule
- if _, found := p.rules[name]; !found {
- p.rules[name] = x
- } else {
- p.error(pos, "format rule already declared: "+name)
- }
-
- default:
- p.errorExpected(p.pos, "package declaration or format rule")
- p.next() // make progress in any case
- }
-
- if p.tok == token.SEMICOLON {
- p.next()
- } else {
- break
- }
- }
- p.expect(token.EOF)
-}
-
-
-func remap(p *parser, name string) string {
- i := strings.Index(name, ".")
- if i >= 0 {
- packageName, suffix := name[0:i], name[i:]
- // lookup package
- if importPath, found := p.packs[packageName]; found {
- name = importPath + suffix
- } else {
- var invalidPos token.Position
- p.Error(invalidPos, "package not declared: "+packageName)
- }
- }
- return name
-}
-
-
-// Parse parses a set of format productions from source src. Custom
-// formatters may be provided via a map of formatter functions. If
-// there are no errors, the result is a Format and the error is nil.
-// Otherwise the format is nil and a non-empty ErrorList is returned.
-//
-func Parse(fset *token.FileSet, filename string, src []byte, fmap FormatterMap) (Format, os.Error) {
- // parse source
- var p parser
- p.init(fset, filename, src)
- p.parseFormat()
-
- // add custom formatters, if any
- for name, form := range fmap {
- name = remap(&p, name)
- if _, found := p.rules[name]; !found {
- p.rules[name] = &custom{name, form}
- } else {
- var invalidPos token.Position
- p.Error(invalidPos, "formatter already declared: "+name)
- }
- }
-
- return p.rules, p.GetError(scanner.NoMultiples)
-}