1 files changed, 0 insertions, 245 deletions
diff --git a/src/pkg/ebnf/ebnf.go b/src/pkg/ebnf/ebnf.go
deleted file mode 100644
index 69da11767..000000000
--- a/src/pkg/ebnf/ebnf.go
+++ /dev/null
@@ -1,245 +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 ebnf is a library for EBNF grammars. The input is text ([]byte)
-// satisfying the following grammar (represented itself in EBNF):
-//
-//	Production  = name "=" [ Expression ] "." .
-//	Expression  = Alternative { "|" Alternative } .
-//	Alternative = Term { Term } .
-//	Term        = name | token [ "…" token ] | Group | Option | Repetition .
-//	Group       = "(" Expression ")" .
-//	Option      = "[" Expression "]" .
-//	Repetition  = "{" Expression "}" .
-//
-// A name is a Go identifier, a token is a Go string, and comments
-// and white space follow the same rules as for the Go language.
-// Production names starting with an uppercase Unicode letter denote
-// non-terminal productions (i.e., productions which allow white-space
-// and comments between tokens); all other production names denote
-// lexical productions.
-//
-package ebnf
-
-import (
-	"go/scanner"
-	"go/token"
-	"os"
-	"unicode"
-	"utf8"
-)
-
-// ----------------------------------------------------------------------------
-// Internal representation
-
-type (
-	// An Expression node represents a production expression.
-	Expression interface {
-		// Pos is the position of the first character of the syntactic construct
-		Pos() token.Pos
-	}
-
-	// An Alternative node represents a non-empty list of alternative expressions.
-	Alternative []Expression // x | y | z
-
-	// A Sequence node represents a non-empty list of sequential expressions.
-	Sequence []Expression // x y z
-
-	// A Name node represents a production name.
-	Name struct {
-		StringPos token.Pos
-		String    string
-	}
-
-	// A Token node represents a literal.
-	Token struct {
-		StringPos token.Pos
-		String    string
-	}
-
-	// A List node represents a range of characters.
-	Range struct {
-		Begin, End *Token // begin ... end
-	}
-
-	// A Group node represents a grouped expression.
-	Group struct {
-		Lparen token.Pos
-		Body   Expression // (body)
-	}
-
-	// An Option node represents an optional expression.
-	Option struct {
-		Lbrack token.Pos
-		Body   Expression // [body]
-	}
-
-	// A Repetition node represents a repeated expression.
-	Repetition struct {
-		Lbrace token.Pos
-		Body   Expression // {body}
-	}
-
-	// A Bad node stands for pieces of source code that lead to a parse error.
-	Bad struct {
-		TokPos token.Pos
-		Error  string // parser error message
-	}
-
-	// A Production node represents an EBNF production.
-	Production struct {
-		Name *Name
-		Expr Expression
-	}
-
-	// A Grammar is a set of EBNF productions. The map
-	// is indexed by production name.
-	//
-	Grammar map[string]*Production
-)
-
-func (x Alternative) Pos() token.Pos { return x[0].Pos() } // the parser always generates non-empty Alternative
-func (x Sequence) Pos() token.Pos    { return x[0].Pos() } // the parser always generates non-empty Sequences
-func (x *Name) Pos() token.Pos       { return x.StringPos }
-func (x *Token) Pos() token.Pos      { return x.StringPos }
-func (x *Range) Pos() token.Pos      { return x.Begin.Pos() }
-func (x *Group) Pos() token.Pos      { return x.Lparen }
-func (x *Option) Pos() token.Pos     { return x.Lbrack }
-func (x *Repetition) Pos() token.Pos { return x.Lbrace }
-func (x *Bad) Pos() token.Pos        { return x.TokPos }
-func (x *Production) Pos() token.Pos { return x.Name.Pos() }
-
-// ----------------------------------------------------------------------------
-// Grammar verification
-
-func isLexical(name string) bool {
-	ch, _ := utf8.DecodeRuneInString(name)
-	return !unicode.IsUpper(ch)
-}
-
-type verifier struct {
-	fset *token.FileSet
-	scanner.ErrorVector
-	worklist []*Production
-	reached  Grammar // set of productions reached from (and including) the root production
-	grammar  Grammar
-}
-
-func (v *verifier) error(pos token.Pos, msg string) {
-	v.Error(v.fset.Position(pos), msg)
-}
-
-func (v *verifier) push(prod *Production) {
-	name := prod.Name.String
-	if _, found := v.reached[name]; !found {
-		v.worklist = append(v.worklist, prod)
-		v.reached[name] = prod
-	}
-}
-
-func (v *verifier) verifyChar(x *Token) int {
-	s := x.String
-	if utf8.RuneCountInString(s) != 1 {
-		v.error(x.Pos(), "single char expected, found "+s)
-		return 0
-	}
-	ch, _ := utf8.DecodeRuneInString(s)
-	return ch
-}
-
-func (v *verifier) verifyExpr(expr Expression, lexical bool) {
-	switch x := expr.(type) {
-	case nil:
-		// empty expression
-	case Alternative:
-		for _, e := range x {
-			v.verifyExpr(e, lexical)
-		}
-	case Sequence:
-		for _, e := range x {
-			v.verifyExpr(e, lexical)
-		}
-	case *Name:
-		// a production with this name must exist;
-		// add it to the worklist if not yet processed
-		if prod, found := v.grammar[x.String]; found {
-			v.push(prod)
-		} else {
-			v.error(x.Pos(), "missing production "+x.String)
-		}
-		// within a lexical production references
-		// to non-lexical productions are invalid
-		if lexical && !isLexical(x.String) {
-			v.error(x.Pos(), "reference to non-lexical production "+x.String)
-		}
-	case *Token:
-		// nothing to do for now
-	case *Range:
-		i := v.verifyChar(x.Begin)
-		j := v.verifyChar(x.End)
-		if i >= j {
-			v.error(x.Pos(), "decreasing character range")
-		}
-	case *Group:
-		v.verifyExpr(x.Body, lexical)
-	case *Option:
-		v.verifyExpr(x.Body, lexical)
-	case *Repetition:
-		v.verifyExpr(x.Body, lexical)
-	default:
-		panic("unreachable")
-	}
-}
-
-func (v *verifier) verify(fset *token.FileSet, grammar Grammar, start string) {
-	// find root production
-	root, found := grammar[start]
-	if !found {
-		// token.NoPos doesn't require a file set;
-		// ok to set v.fset only afterwards
-		v.error(token.NoPos, "no start production "+start)
-		return
-	}
-
-	// initialize verifier
-	v.fset = fset
-	v.ErrorVector.Reset()
-	v.worklist = v.worklist[0:0]
-	v.reached = make(Grammar)
-	v.grammar = grammar
-
-	// work through the worklist
-	v.push(root)
-	for {
-		n := len(v.worklist) - 1
-		if n < 0 {
-			break
-		}
-		prod := v.worklist[n]
-		v.worklist = v.worklist[0:n]
-		v.verifyExpr(prod.Expr, isLexical(prod.Name.String))
-	}
-
-	// check if all productions were reached
-	if len(v.reached) < len(v.grammar) {
-		for name, prod := range v.grammar {
-			if _, found := v.reached[name]; !found {
-				v.error(prod.Pos(), name+" is unreachable")
-			}
-		}
-	}
-}
-
-// Verify checks that:
-//	- all productions used are defined
-//	- all productions defined are used when beginning at start
-//	- lexical productions refer only to other lexical productions
-//
-// Position information is interpreted relative to the file set fset.
-//
-func Verify(fset *token.FileSet, grammar Grammar, start string) os.Error {
-	var v verifier
-	v.verify(fset, grammar, start)
-	return v.GetError(scanner.Sorted)
-}