diff options
Diffstat (limited to 'src/pkg/go/token')
| -rw-r--r-- | src/pkg/go/token/Makefile | 12 | ||||
| -rw-r--r-- | src/pkg/go/token/position.go | 457 | ||||
| -rw-r--r-- | src/pkg/go/token/position_test.go | 189 | ||||
| -rw-r--r-- | src/pkg/go/token/token.go | 318 |
4 files changed, 0 insertions, 976 deletions
diff --git a/src/pkg/go/token/Makefile b/src/pkg/go/token/Makefile deleted file mode 100644 index 4a4e64dc8..000000000 --- a/src/pkg/go/token/Makefile +++ /dev/null @@ -1,12 +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. - -include ../../../Make.inc - -TARG=go/token -GOFILES=\ - position.go\ - token.go\ - -include ../../../Make.pkg diff --git a/src/pkg/go/token/position.go b/src/pkg/go/token/position.go deleted file mode 100644 index 23a3cc00f..000000000 --- a/src/pkg/go/token/position.go +++ /dev/null @@ -1,457 +0,0 @@ -// 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. - -// TODO(gri) consider making this a separate package outside the go directory. - -package token - -import ( - "fmt" - "sort" - "sync" -) - - -// Position describes an arbitrary source position -// including the file, line, and column location. -// A Position is valid if the line number is > 0. -// -type Position struct { - Filename string // filename, if any - Offset int // offset, starting at 0 - Line int // line number, starting at 1 - Column int // column number, starting at 1 (character count) -} - - -// IsValid returns true if the position is valid. -func (pos *Position) IsValid() bool { return pos.Line > 0 } - - -// String returns a string in one of several forms: -// -// file:line:column valid position with file name -// line:column valid position without file name -// file invalid position with file name -// - invalid position without file name -// -func (pos Position) String() string { - s := pos.Filename - if pos.IsValid() { - if s != "" { - s += ":" - } - s += fmt.Sprintf("%d:%d", pos.Line, pos.Column) - } - if s == "" { - s = "-" - } - return s -} - - -// Pos is a compact encoding of a source position within a file set. -// It can be converted into a Position for a more convenient, but much -// larger, representation. -// -// The Pos value for a given file is a number in the range [base, base+size], -// where base and size are specified when adding the file to the file set via -// AddFile. -// -// To create the Pos value for a specific source offset, first add -// the respective file to the current file set (via FileSet.AddFile) -// and then call File.Pos(offset) for that file. Given a Pos value p -// for a specific file set fset, the corresponding Position value is -// obtained by calling fset.Position(p). -// -// Pos values can be compared directly with the usual comparison operators: -// If two Pos values p and q are in the same file, comparing p and q is -// equivalent to comparing the respective source file offsets. If p and q -// are in different files, p < q is true if the file implied by p was added -// to the respective file set before the file implied by q. -// -type Pos int - - -// The zero value for Pos is NoPos; there is no file and line information -// associated with it, and NoPos().IsValid() is false. NoPos is always -// smaller than any other Pos value. The corresponding Position value -// for NoPos is the zero value for Position. -// -const NoPos Pos = 0 - - -// IsValid returns true if the position is valid. -func (p Pos) IsValid() bool { - return p != NoPos -} - - -func searchFiles(a []*File, x int) int { - return sort.Search(len(a), func(i int) bool { return a[i].base > x }) - 1 -} - - -func (s *FileSet) file(p Pos) *File { - if f := s.last; f != nil && f.base <= int(p) && int(p) <= f.base+f.size { - return f - } - if i := searchFiles(s.files, int(p)); i >= 0 { - f := s.files[i] - // f.base <= int(p) by definition of searchFiles - if int(p) <= f.base+f.size { - s.last = f - return f - } - } - return nil -} - - -// File returns the file which contains the position p. -// If no such file is found (for instance for p == NoPos), -// the result is nil. -// -func (s *FileSet) File(p Pos) (f *File) { - if p != NoPos { - s.mutex.RLock() - f = s.file(p) - s.mutex.RUnlock() - } - return -} - - -func (f *File) position(p Pos) (pos Position) { - offset := int(p) - f.base - pos.Offset = offset - pos.Filename, pos.Line, pos.Column = f.info(offset) - return -} - - -// Position converts a Pos in the fileset into a general Position. -func (s *FileSet) Position(p Pos) (pos Position) { - if p != NoPos { - // TODO(gri) consider optimizing the case where p - // is in the last file added, or perhaps - // looked at - will eliminate one level - // of search - s.mutex.RLock() - if f := s.file(p); f != nil { - pos = f.position(p) - } - s.mutex.RUnlock() - } - return -} - - -type lineInfo struct { - offset int - filename string - line int -} - - -// AddLineInfo adds alternative file and line number information for -// a given file offset. The offset must be larger than the offset for -// the previously added alternative line info and smaller than the -// file size; otherwise the information is ignored. -// -// AddLineInfo is typically used to register alternative position -// information for //line filename:line comments in source files. -// -func (f *File) AddLineInfo(offset int, filename string, line int) { - f.set.mutex.Lock() - if i := len(f.infos); i == 0 || f.infos[i-1].offset < offset && offset < f.size { - f.infos = append(f.infos, lineInfo{offset, filename, line}) - } - f.set.mutex.Unlock() -} - - -// A File is a handle for a file belonging to a FileSet. -// A File has a name, size, and line offset table. -// -type File struct { - set *FileSet - name string // file name as provided to AddFile - base int // Pos value range for this file is [base...base+size] - size int // file size as provided to AddFile - - // lines and infos are protected by set.mutex - lines []int - infos []lineInfo -} - - -// Name returns the file name of file f as registered with AddFile. -func (f *File) Name() string { - return f.name -} - - -// Base returns the base offset of file f as registered with AddFile. -func (f *File) Base() int { - return f.base -} - - -// Size returns the size of file f as registered with AddFile. -func (f *File) Size() int { - return f.size -} - - -// LineCount returns the number of lines in file f. -func (f *File) LineCount() int { - f.set.mutex.RLock() - n := len(f.lines) - f.set.mutex.RUnlock() - return n -} - - -// AddLine adds the line offset for a new line. -// The line offset must be larger than the offset for the previous line -// and smaller than the file size; otherwise the line offset is ignored. -// -func (f *File) AddLine(offset int) { - f.set.mutex.Lock() - if i := len(f.lines); (i == 0 || f.lines[i-1] < offset) && offset < f.size { - f.lines = append(f.lines, offset) - } - f.set.mutex.Unlock() -} - - -// SetLines sets the line offsets for a file and returns true if successful. -// The line offsets are the offsets of the first character of each line; -// for instance for the content "ab\nc\n" the line offsets are {0, 3}. -// An empty file has an empty line offset table. -// Each line offset must be larger than the offset for the previous line -// and smaller than the file size; otherwise SetLines fails and returns -// false. -// -func (f *File) SetLines(lines []int) bool { - // verify validity of lines table - size := f.size - for i, offset := range lines { - if i > 0 && offset <= lines[i-1] || size <= offset { - return false - } - } - - // set lines table - f.set.mutex.Lock() - f.lines = lines - f.set.mutex.Unlock() - return true -} - - -// SetLinesForContent sets the line offsets for the given file content. -func (f *File) SetLinesForContent(content []byte) { - var lines []int - line := 0 - for offset, b := range content { - if line >= 0 { - lines = append(lines, line) - } - line = -1 - if b == '\n' { - line = offset + 1 - } - } - - // set lines table - f.set.mutex.Lock() - f.lines = lines - f.set.mutex.Unlock() -} - - -// Pos returns the Pos value for the given file offset; -// the offset must be <= f.Size(). -// f.Pos(f.Offset(p)) == p. -// -func (f *File) Pos(offset int) Pos { - if offset > f.size { - panic("illegal file offset") - } - return Pos(f.base + offset) -} - - -// Offset returns the offset for the given file position p; -// p must be a valid Pos value in that file. -// f.Offset(f.Pos(offset)) == offset. -// -func (f *File) Offset(p Pos) int { - if int(p) < f.base || int(p) > f.base+f.size { - panic("illegal Pos value") - } - return int(p) - f.base -} - - -// Line returns the line number for the given file position p; -// p must be a Pos value in that file or NoPos. -// -func (f *File) Line(p Pos) int { - // TODO(gri) this can be implemented much more efficiently - return f.Position(p).Line -} - - -// Position returns the Position value for the given file position p; -// p must be a Pos value in that file or NoPos. -// -func (f *File) Position(p Pos) (pos Position) { - if p != NoPos { - if int(p) < f.base || int(p) > f.base+f.size { - panic("illegal Pos value") - } - pos = f.position(p) - } - return -} - - -func searchInts(a []int, x int) int { - // This function body is a manually inlined version of: - // - // return sort.Search(len(a), func(i int) bool { return a[i] > x }) - 1 - // - // With better compiler optimizations, this may not be needed in the - // future, but at the moment this change improves the go/printer - // benchmark performance by ~30%. This has a direct impact on the - // speed of gofmt and thus seems worthwhile (2011-04-29). - i, j := 0, len(a) - for i < j { - h := i + (j-i)/2 // avoid overflow when computing h - // i ≤ h < j - if a[h] <= x { - i = h + 1 - } else { - j = h - } - } - return i - 1 -} - - -func searchLineInfos(a []lineInfo, x int) int { - return sort.Search(len(a), func(i int) bool { return a[i].offset > x }) - 1 -} - - -// info returns the file name, line, and column number for a file offset. -func (f *File) info(offset int) (filename string, line, column int) { - filename = f.name - if i := searchInts(f.lines, offset); i >= 0 { - line, column = i+1, offset-f.lines[i]+1 - } - if len(f.infos) > 0 { - // almost no files have extra line infos - if i := searchLineInfos(f.infos, offset); i >= 0 { - alt := &f.infos[i] - filename = alt.filename - if i := searchInts(f.lines, alt.offset); i >= 0 { - line += alt.line - i - 1 - } - } - } - return -} - - -// A FileSet represents a set of source files. -// Methods of file sets are synchronized; multiple goroutines -// may invoke them concurrently. -// -type FileSet struct { - mutex sync.RWMutex // protects the file set - base int // base offset for the next file - files []*File // list of files in the order added to the set - last *File // cache of last file looked up -} - - -// NewFileSet creates a new file set. -func NewFileSet() *FileSet { - s := new(FileSet) - s.base = 1 // 0 == NoPos - return s -} - - -// Base returns the minimum base offset that must be provided to -// AddFile when adding the next file. -// -func (s *FileSet) Base() int { - s.mutex.RLock() - b := s.base - s.mutex.RUnlock() - return b - -} - - -// AddFile adds a new file with a given filename, base offset, and file size -// to the file set s and returns the file. Multiple files may have the same -// name. The base offset must not be smaller than the FileSet's Base(), and -// size must not be negative. -// -// Adding the file will set the file set's Base() value to base + size + 1 -// as the minimum base value for the next file. The following relationship -// exists between a Pos value p for a given file offset offs: -// -// int(p) = base + offs -// -// with offs in the range [0, size] and thus p in the range [base, base+size]. -// For convenience, File.Pos may be used to create file-specific position -// values from a file offset. -// -func (s *FileSet) AddFile(filename string, base, size int) *File { - s.mutex.Lock() - defer s.mutex.Unlock() - if base < s.base || size < 0 { - panic("illegal base or size") - } - // base >= s.base && size >= 0 - f := &File{s, filename, base, size, []int{0}, nil} - base += size + 1 // +1 because EOF also has a position - if base < 0 { - panic("token.Pos offset overflow (> 2G of source code in file set)") - } - // add the file to the file set - s.base = base - s.files = append(s.files, f) - s.last = f - return f -} - - -// Files returns the files added to the file set. -func (s *FileSet) Files() <-chan *File { - ch := make(chan *File) - go func() { - for i := 0; ; i++ { - var f *File - s.mutex.RLock() - if i < len(s.files) { - f = s.files[i] - } - s.mutex.RUnlock() - if f == nil { - break - } - ch <- f - } - close(ch) - }() - return ch -} diff --git a/src/pkg/go/token/position_test.go b/src/pkg/go/token/position_test.go deleted file mode 100644 index 979c9b1e8..000000000 --- a/src/pkg/go/token/position_test.go +++ /dev/null @@ -1,189 +0,0 @@ -// 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 token - -import ( - "fmt" - "testing" -) - - -func checkPos(t *testing.T, msg string, p, q Position) { - if p.Filename != q.Filename { - t.Errorf("%s: expected filename = %q; got %q", msg, q.Filename, p.Filename) - } - if p.Offset != q.Offset { - t.Errorf("%s: expected offset = %d; got %d", msg, q.Offset, p.Offset) - } - if p.Line != q.Line { - t.Errorf("%s: expected line = %d; got %d", msg, q.Line, p.Line) - } - if p.Column != q.Column { - t.Errorf("%s: expected column = %d; got %d", msg, q.Column, p.Column) - } -} - - -func TestNoPos(t *testing.T) { - if NoPos.IsValid() { - t.Errorf("NoPos should not be valid") - } - var fset *FileSet - checkPos(t, "nil NoPos", fset.Position(NoPos), Position{}) - fset = NewFileSet() - checkPos(t, "fset NoPos", fset.Position(NoPos), Position{}) -} - - -var tests = []struct { - filename string - source []byte // may be nil - size int - lines []int -}{ - {"a", []byte{}, 0, []int{}}, - {"b", []byte("01234"), 5, []int{0}}, - {"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}}, - {"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}}, - {"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}}, - {"f", []byte("package p\n\nimport \"fmt\""), 23, []int{0, 10, 11}}, - {"g", []byte("package p\n\nimport \"fmt\"\n"), 24, []int{0, 10, 11}}, - {"h", []byte("package p\n\nimport \"fmt\"\n "), 25, []int{0, 10, 11, 24}}, -} - - -func linecol(lines []int, offs int) (int, int) { - prevLineOffs := 0 - for line, lineOffs := range lines { - if offs < lineOffs { - return line, offs - prevLineOffs + 1 - } - prevLineOffs = lineOffs - } - return len(lines), offs - prevLineOffs + 1 -} - - -func verifyPositions(t *testing.T, fset *FileSet, f *File, lines []int) { - for offs := 0; offs < f.Size(); offs++ { - p := f.Pos(offs) - offs2 := f.Offset(p) - if offs2 != offs { - t.Errorf("%s, Offset: expected offset %d; got %d", f.Name(), offs, offs2) - } - line, col := linecol(lines, offs) - msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p) - checkPos(t, msg, f.Position(f.Pos(offs)), Position{f.Name(), offs, line, col}) - checkPos(t, msg, fset.Position(p), Position{f.Name(), offs, line, col}) - } -} - - -func makeTestSource(size int, lines []int) []byte { - src := make([]byte, size) - for _, offs := range lines { - if offs > 0 { - src[offs-1] = '\n' - } - } - return src -} - - -func TestPositions(t *testing.T) { - const delta = 7 // a non-zero base offset increment - fset := NewFileSet() - for _, test := range tests { - // verify consistency of test case - if test.source != nil && len(test.source) != test.size { - t.Errorf("%s: inconsistent test case: expected file size %d; got %d", test.filename, test.size, len(test.source)) - } - - // add file and verify name and size - f := fset.AddFile(test.filename, fset.Base()+delta, test.size) - if f.Name() != test.filename { - t.Errorf("expected filename %q; got %q", test.filename, f.Name()) - } - if f.Size() != test.size { - t.Errorf("%s: expected file size %d; got %d", f.Name(), test.size, f.Size()) - } - if fset.File(f.Pos(0)) != f { - t.Errorf("%s: f.Pos(0) was not found in f", f.Name()) - } - - // add lines individually and verify all positions - for i, offset := range test.lines { - f.AddLine(offset) - if f.LineCount() != i+1 { - t.Errorf("%s, AddLine: expected line count %d; got %d", f.Name(), i+1, f.LineCount()) - } - // adding the same offset again should be ignored - f.AddLine(offset) - if f.LineCount() != i+1 { - t.Errorf("%s, AddLine: expected unchanged line count %d; got %d", f.Name(), i+1, f.LineCount()) - } - verifyPositions(t, fset, f, test.lines[0:i+1]) - } - - // add lines with SetLines and verify all positions - if ok := f.SetLines(test.lines); !ok { - t.Errorf("%s: SetLines failed", f.Name()) - } - if f.LineCount() != len(test.lines) { - t.Errorf("%s, SetLines: expected line count %d; got %d", f.Name(), len(test.lines), f.LineCount()) - } - verifyPositions(t, fset, f, test.lines) - - // add lines with SetLinesForContent and verify all positions - src := test.source - if src == nil { - // no test source available - create one from scratch - src = makeTestSource(test.size, test.lines) - } - f.SetLinesForContent(src) - if f.LineCount() != len(test.lines) { - t.Errorf("%s, SetLinesForContent: expected line count %d; got %d", f.Name(), len(test.lines), f.LineCount()) - } - verifyPositions(t, fset, f, test.lines) - } -} - - -func TestLineInfo(t *testing.T) { - fset := NewFileSet() - f := fset.AddFile("foo", fset.Base(), 500) - lines := []int{0, 42, 77, 100, 210, 220, 277, 300, 333, 401} - // add lines individually and provide alternative line information - for _, offs := range lines { - f.AddLine(offs) - f.AddLineInfo(offs, "bar", 42) - } - // verify positions for all offsets - for offs := 0; offs <= f.Size(); offs++ { - p := f.Pos(offs) - _, col := linecol(lines, offs) - msg := fmt.Sprintf("%s (offs = %d, p = %d)", f.Name(), offs, p) - checkPos(t, msg, f.Position(f.Pos(offs)), Position{"bar", offs, 42, col}) - checkPos(t, msg, fset.Position(p), Position{"bar", offs, 42, col}) - } -} - - -func TestFiles(t *testing.T) { - fset := NewFileSet() - for i, test := range tests { - fset.AddFile(test.filename, fset.Base(), test.size) - j := 0 - for g := range fset.Files() { - if g.Name() != tests[j].filename { - t.Errorf("expected filename = %s; got %s", tests[j].filename, g.Name()) - } - j++ - } - if j != i+1 { - t.Errorf("expected %d files; got %d", i+1, j) - } - } -} diff --git a/src/pkg/go/token/token.go b/src/pkg/go/token/token.go deleted file mode 100644 index c2ec80ae1..000000000 --- a/src/pkg/go/token/token.go +++ /dev/null @@ -1,318 +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 token defines constants representing the lexical tokens of the Go -// programming language and basic operations on tokens (printing, predicates). -// -package token - -import "strconv" - - -// Token is the set of lexical tokens of the Go programming language. -type Token int - -// The list of tokens. -const ( - // Special tokens - ILLEGAL Token = iota - EOF - COMMENT - - literal_beg - // Identifiers and basic type literals - // (these tokens stand for classes of literals) - IDENT // main - INT // 12345 - FLOAT // 123.45 - IMAG // 123.45i - CHAR // 'a' - STRING // "abc" - literal_end - - operator_beg - // Operators and delimiters - ADD // + - SUB // - - MUL // * - QUO // / - REM // % - - AND // & - OR // | - XOR // ^ - SHL // << - SHR // >> - AND_NOT // &^ - - ADD_ASSIGN // += - SUB_ASSIGN // -= - MUL_ASSIGN // *= - QUO_ASSIGN // /= - REM_ASSIGN // %= - - AND_ASSIGN // &= - OR_ASSIGN // |= - XOR_ASSIGN // ^= - SHL_ASSIGN // <<= - SHR_ASSIGN // >>= - AND_NOT_ASSIGN // &^= - - LAND // && - LOR // || - ARROW // <- - INC // ++ - DEC // -- - - EQL // == - LSS // < - GTR // > - ASSIGN // = - NOT // ! - - NEQ // != - LEQ // <= - GEQ // >= - DEFINE // := - ELLIPSIS // ... - - LPAREN // ( - LBRACK // [ - LBRACE // { - COMMA // , - PERIOD // . - - RPAREN // ) - RBRACK // ] - RBRACE // } - SEMICOLON // ; - COLON // : - operator_end - - keyword_beg - // Keywords - BREAK - CASE - CHAN - CONST - CONTINUE - - DEFAULT - DEFER - ELSE - FALLTHROUGH - FOR - - FUNC - GO - GOTO - IF - IMPORT - - INTERFACE - MAP - PACKAGE - RANGE - RETURN - - SELECT - STRUCT - SWITCH - TYPE - VAR - keyword_end -) - - -var tokens = [...]string{ - ILLEGAL: "ILLEGAL", - - EOF: "EOF", - COMMENT: "COMMENT", - - IDENT: "IDENT", - INT: "INT", - FLOAT: "FLOAT", - IMAG: "IMAG", - CHAR: "CHAR", - STRING: "STRING", - - ADD: "+", - SUB: "-", - MUL: "*", - QUO: "/", - REM: "%", - - AND: "&", - OR: "|", - XOR: "^", - SHL: "<<", - SHR: ">>", - AND_NOT: "&^", - - ADD_ASSIGN: "+=", - SUB_ASSIGN: "-=", - MUL_ASSIGN: "*=", - QUO_ASSIGN: "/=", - REM_ASSIGN: "%=", - - AND_ASSIGN: "&=", - OR_ASSIGN: "|=", - XOR_ASSIGN: "^=", - SHL_ASSIGN: "<<=", - SHR_ASSIGN: ">>=", - AND_NOT_ASSIGN: "&^=", - - LAND: "&&", - LOR: "||", - ARROW: "<-", - INC: "++", - DEC: "--", - - EQL: "==", - LSS: "<", - GTR: ">", - ASSIGN: "=", - NOT: "!", - - NEQ: "!=", - LEQ: "<=", - GEQ: ">=", - DEFINE: ":=", - ELLIPSIS: "...", - - LPAREN: "(", - LBRACK: "[", - LBRACE: "{", - COMMA: ",", - PERIOD: ".", - - RPAREN: ")", - RBRACK: "]", - RBRACE: "}", - SEMICOLON: ";", - COLON: ":", - - BREAK: "break", - CASE: "case", - CHAN: "chan", - CONST: "const", - CONTINUE: "continue", - - DEFAULT: "default", - DEFER: "defer", - ELSE: "else", - FALLTHROUGH: "fallthrough", - FOR: "for", - - FUNC: "func", - GO: "go", - GOTO: "goto", - IF: "if", - IMPORT: "import", - - INTERFACE: "interface", - MAP: "map", - PACKAGE: "package", - RANGE: "range", - RETURN: "return", - - SELECT: "select", - STRUCT: "struct", - SWITCH: "switch", - TYPE: "type", - VAR: "var", -} - - -// String returns the string corresponding to the token tok. -// For operators, delimiters, and keywords the string is the actual -// token character sequence (e.g., for the token ADD, the string is -// "+"). For all other tokens the string corresponds to the token -// constant name (e.g. for the token IDENT, the string is "IDENT"). -// -func (tok Token) String() string { - s := "" - if 0 <= tok && tok < Token(len(tokens)) { - s = tokens[tok] - } - if s == "" { - s = "token(" + strconv.Itoa(int(tok)) + ")" - } - return s -} - - -// A set of constants for precedence-based expression parsing. -// Non-operators have lowest precedence, followed by operators -// starting with precedence 1 up to unary operators. The highest -// precedence corresponds serves as "catch-all" precedence for -// selector, indexing, and other operator and delimiter tokens. -// -const ( - LowestPrec = 0 // non-operators - UnaryPrec = 6 - HighestPrec = 7 -) - - -// Precedence returns the operator precedence of the binary -// operator op. If op is not a binary operator, the result -// is LowestPrecedence. -// -func (op Token) Precedence() int { - switch op { - case LOR: - return 1 - case LAND: - return 2 - case EQL, NEQ, LSS, LEQ, GTR, GEQ: - return 3 - case ADD, SUB, OR, XOR: - return 4 - case MUL, QUO, REM, SHL, SHR, AND, AND_NOT: - return 5 - } - return LowestPrec -} - - -var keywords map[string]Token - -func init() { - keywords = make(map[string]Token) - for i := keyword_beg + 1; i < keyword_end; i++ { - keywords[tokens[i]] = i - } -} - - -// Lookup maps an identifier to its keyword token or IDENT (if not a keyword). -// -func Lookup(ident []byte) Token { - // TODO Maps with []byte key are illegal because []byte does not - // support == . Should find a more efficient solution eventually. - if tok, is_keyword := keywords[string(ident)]; is_keyword { - return tok - } - return IDENT -} - - -// Predicates - -// IsLiteral returns true for tokens corresponding to identifiers -// and basic type literals; returns false otherwise. -// -func (tok Token) IsLiteral() bool { return literal_beg < tok && tok < literal_end } - -// IsOperator returns true for tokens corresponding to operators and -// delimiters; returns false otherwise. -// -func (tok Token) IsOperator() bool { return operator_beg < tok && tok < operator_end } - -// IsKeyword returns true for tokens corresponding to keywords; -// returns false otherwise. -// -func (tok Token) IsKeyword() bool { return keyword_beg < tok && tok < keyword_end } |