mirror of
https://github.com/golang/go
synced 2024-11-22 23:50:03 -07:00
- added Filename field to token.Position
- handle //line filename:line comments in scanner - moved error handling code used by various scanner clients to errors.go - added extra tests R=rsc DELTA=385 (343 added, 18 deleted, 24 changed) OCL=31551 CL=31601
This commit is contained in:
Robert Griesemer
parent
10e995fba8
commit
14228f3898
@ -2,8 +2,9 @@
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# Use of this source code is governed by a BSD-style
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# license that can be found in the LICENSE file.
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# DO NOT EDIT. Automatically generated by gobuild.
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# gobuild -m >Makefile
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# gobuild -m scanner.go errors.go >Makefile
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D=/go/
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@ -20,7 +21,7 @@ test: packages
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coverage: packages
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gotest
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6cov -g `pwd` | grep -v '_test\.go:'
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6cov -g $$(pwd) | grep -v '_test\.go:'
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%.$O: %.go
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$(GC) -I_obj $*.go
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@ -32,16 +33,23 @@ coverage: packages
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$(AS) $*.s
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O1=\
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errors.$O\
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O2=\
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scanner.$O\
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phases: a1
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phases: a1 a2
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_obj$D/scanner.a: phases
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a1: $(O1)
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$(AR) grc _obj$D/scanner.a scanner.$O
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$(AR) grc _obj$D/scanner.a errors.$O
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rm -f $(O1)
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a2: $(O2)
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$(AR) grc _obj$D/scanner.a scanner.$O
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rm -f $(O2)
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newpkg: clean
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mkdir -p _obj$D
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@ -49,6 +57,7 @@ newpkg: clean
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$(O1): newpkg
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$(O2): a1
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$(O3): a2
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nuke: clean
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rm -f $(GOROOT)/pkg/$(GOOS)_$(GOARCH)$D/scanner.a
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203
src/pkg/go/scanner/errors.go
Normal file
203
src/pkg/go/scanner/errors.go
Normal file
@ -0,0 +1,203 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package scanner
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import (
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"container/vector";
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"fmt";
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"go/token";
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"io";
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"os";
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"sort";
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)
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// An implementation of an ErrorHandler may be provided to the Scanner.
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// If a syntax error is encountered and a handler was installed, Error
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// is called with a position and an error message. The position points
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// to the beginning of the offending token.
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//
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type ErrorHandler interface {
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Error(pos token.Position, msg string);
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}
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// ErrorVector implements the ErrorHandler interface. It must be
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// initialized with Init(). It maintains a list of errors which can
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// be retrieved with GetErrorList and GetError.
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//
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// A common usage pattern is to embed an ErrorVector alongside a
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// scanner in a data structure that uses the scanner. By passing a
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// reference to an ErrorVector to the scanner's Init call, default
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// error handling is obtained.
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//
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type ErrorVector struct {
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errors vector.Vector;
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}
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// Init initializes an ErrorVector.
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func (h *ErrorVector) Init() {
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h.errors.Init(0);
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}
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// NewErrorVector creates a new ErrorVector.
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func NewErrorVector() *ErrorVector {
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h := new(ErrorVector);
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h.Init();
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return h;
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}
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// ErrorCount returns the number of errors collected.
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func (h *ErrorVector) ErrorCount() int {
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return h.errors.Len();
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}
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// Within ErrorVector, an error is represented by an Error node. The
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// position Pos, if valid, points to the beginning of the offending
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// token, and the error condition is described by Msg.
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//
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type Error struct {
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Pos token.Position;
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Msg string;
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}
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func (e *Error) String() string {
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s := e.Pos.Filename;
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if s != "" {
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s += ":";
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}
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if e.Pos.IsValid() {
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s += fmt.Sprintf("%d:%d:", e.Pos.Line, e.Pos.Column);
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}
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if s != "" {
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s += " ";
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}
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return s + e.Msg;
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}
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// An ErrorList is a (possibly sorted) list of Errors.
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type ErrorList []*Error
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// ErrorList implements the SortInterface.
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func (p ErrorList) Len() int { return len(p); }
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func (p ErrorList) Swap(i, j int) { p[i], p[j] = p[j], p[i]; }
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func (p ErrorList) Less(i, j int) bool {
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e := &p[i].Pos;
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f := &p[j].Pos;
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// Note that it is not sufficient to simply compare file offsets because
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// the offsets do not reflect modified line information (through //line
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// comments).
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if e.Filename < f.Filename {
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return true;
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}
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if e.Filename == f.Filename {
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if e.Line < f.Line {
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return true;
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}
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if e.Line == f.Line {
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return e.Column < f.Column;
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}
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}
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return false;
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}
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func (p ErrorList) String() string {
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switch len(p) {
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case 0:
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return "unspecified error";
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case 1:
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return p[0].String();
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}
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return fmt.Sprintf("%s (and %d more errors)", p[0].String(), len(p) - 1);
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}
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// These constants control the construction of the ErrorList
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// returned by GetErrors.
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//
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const (
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Raw = iota; // leave error list unchanged
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Sorted; // sort error list by file, line, and column number
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NoMultiples; // sort error list and leave only the first error per line
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)
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// GetErrorList returns the list of errors collected by an ErrorVector.
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// The construction of the ErrorList returned is controlled by the mode
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// parameter. If there are no errors, the result is nil.
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//
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func (h *ErrorVector) GetErrorList(mode int) ErrorList {
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if h.errors.Len() == 0 {
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return nil;
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}
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list := make(ErrorList, h.errors.Len());
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for i := 0; i < h.errors.Len(); i++ {
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list[i] = h.errors.At(i).(*Error);
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}
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if mode >= Sorted {
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sort.Sort(list);
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}
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if mode >= NoMultiples {
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var last token.Position; // initial last.Line is != any legal error line
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i := 0;
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for _, e := range list {
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if e.Pos.Filename != last.Filename || e.Pos.Line != last.Line {
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last = e.Pos;
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list[i] = e;
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i++;
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}
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}
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list = list[0 : i];
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}
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return list;
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}
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// GetError is like GetErrorList, but it returns an os.Error instead
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// so that a nil result can be assigned to an os.Error variable and
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// remains nil.
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//
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func (h *ErrorVector) GetError(mode int) os.Error {
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if h.errors.Len() == 0 {
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return nil;
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}
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return h.GetErrorList(mode);
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}
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// ErrorVector implements the ErrorHandler interface.
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func (h *ErrorVector) Error(pos token.Position, msg string) {
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h.errors.Push(&Error{pos, msg});
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}
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// PrintError is a utility function that prints a list of errors to w,
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// one error per line, if the err parameter is an ErrorList. Otherwise
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// it prints the err string.
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//
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func PrintError(w io.Writer, err os.Error) {
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if list, ok := err.(ErrorList); ok {
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for _, e := range list {
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fmt.Fprintf(w, "%s\n", e);
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}
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} else {
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fmt.Fprintf(w, "%s\n", err);
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}
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}
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@ -9,23 +9,15 @@
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package scanner
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import (
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"bytes";
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"go/token";
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"go/scanner";
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"strconv";
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"unicode";
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"utf8";
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)
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// An implementation of an ErrorHandler may be provided to the Scanner.
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// If a syntax error is encountered and a handler was installed, Error
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// is called with a position and an error message. The position points
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// to the beginning of the offending token.
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//
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type ErrorHandler interface {
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Error(pos token.Position, msg string);
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}
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// A Scanner holds the scanner's internal state while processing
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// a given text. It can be allocated as part of another data
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// structure but must be initialized via Init before use. For
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@ -84,15 +76,17 @@ const (
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// Init prepares the scanner S to tokenize the text src. Calls to Scan
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// will use the error handler err if they encounter a syntax error and
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// err is not nil. Also, for each error encountered, the Scanner field
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// ErrorCount is incremented by one. The mode parameter determines how
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// comments and illegal characters are handled.
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// ErrorCount is incremented by one. The filename parameter is used as
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// filename in the token.Position returned by Scan for each token. The
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// mode parameter determines how comments and illegal characters are
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// handled.
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//
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func (S *Scanner) Init(src []byte, err ErrorHandler, mode uint) {
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func (S *Scanner) Init(filename string, src []byte, err ErrorHandler, mode uint) {
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// Explicitly initialize all fields since a scanner may be reused.
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S.src = src;
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S.err = err;
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S.mode = mode;
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S.pos = token.Position{0, 1, 0};
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S.pos = token.Position{filename, 0, 1, 0};
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S.offset = 0;
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S.ErrorCount = 0;
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S.next();
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@ -133,6 +127,8 @@ func (S *Scanner) expect(ch int) {
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}
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var prefix = []byte{'l', 'i', 'n', 'e', ' '}; // "line "
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func (S *Scanner) scanComment(pos token.Position) {
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// first '/' already consumed
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@ -143,6 +139,22 @@ func (S *Scanner) scanComment(pos token.Position) {
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if S.ch == '\n' {
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// '\n' is not part of the comment
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// (the comment ends on the same line where it started)
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if pos.Column == 1 {
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text := S.src[pos.Offset+2 : S.pos.Offset];
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if bytes.HasPrefix(text, prefix) {
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// comment starts at beginning of line with "//line ";
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// get filename and line number, if any
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i := bytes.Index(text, []byte{':'});
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if i >= 0 {
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if line, err := strconv.Atoi(string(text[i+1 : len(text)])); err == nil && line > 0 {
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// valid //line filename:line comment;
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// update scanner position
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S.pos.Filename = string(text[len(prefix) : i]);
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S.pos.Line = line;
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}
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}
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}
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}
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return;
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}
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}
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@ -492,9 +504,9 @@ scan_again:
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// false (usually when the token value is token.EOF). The result is the number
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// of errors encountered.
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//
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func Tokenize(src []byte, err ErrorHandler, mode uint, f func (pos token.Position, tok token.Token, lit []byte) bool) int {
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func Tokenize(filename string, src []byte, err ErrorHandler, mode uint, f func (pos token.Position, tok token.Token, lit []byte) bool) int {
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var s Scanner;
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s.Init(src, err, mode);
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s.Init(filename, src, err, mode);
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for f(s.Scan()) {
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// action happens in f
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}
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@ -7,6 +7,7 @@ package scanner
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import (
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"go/scanner";
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"go/token";
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"os";
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"strings";
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"testing";
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)
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@ -178,19 +179,35 @@ func NewlineCount(s string) int {
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}
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func checkPos(t *testing.T, lit string, pos, expected token.Position) {
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if pos.Filename != expected.Filename {
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t.Errorf("bad filename for %s: got %s, expected %s", lit, pos.Filename, expected.Filename);
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}
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if pos.Offset != expected.Offset {
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t.Errorf("bad position for %s: got %d, expected %d", lit, pos.Offset, expected.Offset);
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}
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if pos.Line != expected.Line {
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t.Errorf("bad line for %s: got %d, expected %d", lit, pos.Line, expected.Line);
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}
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if pos.Column!= expected.Column {
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t.Errorf("bad column for %s: got %d, expected %d", lit, pos.Column, expected.Column);
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}
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}
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// Verify that calling Scan() provides the correct results.
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func TestScan(t *testing.T) {
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// make source
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var src string;
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for i, e := range tokens {
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for _, e := range tokens {
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src += e.lit + whitespace;
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}
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whitespace_linecount := NewlineCount(whitespace);
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// verify scan
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index := 0;
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eloc := token.Position{0, 1, 1};
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nerrors := scanner.Tokenize(strings.Bytes(src), &TestErrorHandler{t}, scanner.ScanComments,
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epos := token.Position{"", 0, 1, 1};
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nerrors := scanner.Tokenize("", strings.Bytes(src), &TestErrorHandler{t}, scanner.ScanComments,
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func (pos token.Position, tok token.Token, litb []byte) bool {
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e := elt{token.EOF, "", special};
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if index < len(tokens) {
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@ -199,17 +216,9 @@ func TestScan(t *testing.T) {
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lit := string(litb);
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if tok == token.EOF {
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lit = "<EOF>";
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eloc.Column = 0;
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}
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if pos.Offset != eloc.Offset {
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t.Errorf("bad position for %s: got %d, expected %d", lit, pos.Offset, eloc.Offset);
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}
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if pos.Line != eloc.Line {
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t.Errorf("bad line for %s: got %d, expected %d", lit, pos.Line, eloc.Line);
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}
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if pos.Column!= eloc.Column {
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t.Errorf("bad column for %s: got %d, expected %d", lit, pos.Column, eloc.Column);
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epos.Column = 0;
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}
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checkPos(t, lit, pos, epos);
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if tok != e.tok {
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t.Errorf("bad token for %s: got %s, expected %s", lit, tok.String(), e.tok.String());
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}
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@ -219,12 +228,12 @@ func TestScan(t *testing.T) {
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if tokenclass(tok) != e.class {
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t.Errorf("bad class for %s: got %d, expected %d", lit, tokenclass(tok), e.class);
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}
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eloc.Offset += len(lit) + len(whitespace);
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eloc.Line += NewlineCount(lit) + whitespace_linecount;
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epos.Offset += len(lit) + len(whitespace);
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epos.Line += NewlineCount(lit) + whitespace_linecount;
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if tok == token.COMMENT && litb[1] == '/' {
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// correct for unaccounted '/n' in //-style comment
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eloc.Offset++;
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eloc.Line++;
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epos.Offset++;
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epos.Line++;
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}
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index++;
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return tok != token.EOF;
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@ -236,12 +245,60 @@ func TestScan(t *testing.T) {
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}
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type seg struct {
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srcline string; // a line of source text
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filename string; // filename for current token
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line int; // line number for current token
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}
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|
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|
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var segments = []seg{
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// exactly one token per line since the test consumes one token per segment
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seg{ " line1", "TestLineComments", 1 },
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seg{ "\nline2", "TestLineComments", 2 },
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seg{ "\nline3 //line File1.go:100", "TestLineComments", 3 }, // bad line comment, ignored
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seg{ "\nline4", "TestLineComments", 4 },
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seg{ "\n//line File1.go:100\n line100", "File1.go", 100 },
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seg{ "\n//line File2.go:200\n line200", "File2.go", 200 },
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seg{ "\n//line :1\n line1", "", 1 },
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seg{ "\n//line foo:42\n line42", "foo", 42 },
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seg{ "\n //line foo:42\n line44", "foo", 44 }, // bad line comment, ignored
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seg{ "\n//line foo 42\n line46", "foo", 46 }, // bad line comment, ignored
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seg{ "\n//line foo:42 extra text\n line48", "foo", 48 }, // bad line comment, ignored
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seg{ "\n//line foo:42\n line42", "foo", 42 },
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seg{ "\n//line foo:42\n line42", "foo", 42 },
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seg{ "\n//line File1.go:100\n line100", "File1.go", 100 },
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}
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|
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// Verify that comments of the form "//line filename:line" are interpreted correctly.
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func TestLineComments(t *testing.T) {
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// make source
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var src string;
|
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for _, e := range segments {
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src += e.srcline;
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}
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|
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// verify scan
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var S scanner.Scanner;
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S.Init("TestLineComments", strings.Bytes(src), nil, 0);
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for _, s := range segments {
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pos, tok, lit := S.Scan();
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checkPos(t, string(lit), pos, token.Position{s.filename, pos.Offset, s.line, pos.Column});
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}
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|
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if S.ErrorCount != 0 {
|
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t.Errorf("found %d errors", S.ErrorCount);
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}
|
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}
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|
||||
// Verify that initializing the same scanner more then once works correctly.
|
||||
func TestInit(t *testing.T) {
|
||||
var s scanner.Scanner;
|
||||
|
||||
// 1st init
|
||||
s.Init(strings.Bytes("if true { }"), nil, 0);
|
||||
s.Init("", strings.Bytes("if true { }"), nil, 0);
|
||||
s.Scan(); // if
|
||||
s.Scan(); // true
|
||||
pos, tok, lit := s.Scan(); // {
|
||||
@ -250,7 +307,7 @@ func TestInit(t *testing.T) {
|
||||
}
|
||||
|
||||
// 2nd init
|
||||
s.Init(strings.Bytes("go true { ]"), nil, 0);
|
||||
s.Init("", strings.Bytes("go true { ]"), nil, 0);
|
||||
pos, tok, lit = s.Scan(); // go
|
||||
if tok != token.GO {
|
||||
t.Errorf("bad token: got %s, expected %s", tok.String(), token.GO);
|
||||
@ -266,7 +323,7 @@ func TestIllegalChars(t *testing.T) {
|
||||
var s scanner.Scanner;
|
||||
|
||||
const src = "*?*$*@*";
|
||||
s.Init(strings.Bytes(src), &TestErrorHandler{t}, scanner.AllowIllegalChars);
|
||||
s.Init("", strings.Bytes(src), &TestErrorHandler{t}, scanner.AllowIllegalChars);
|
||||
for offs, ch := range src {
|
||||
pos, tok, lit := s.Scan();
|
||||
if pos.Offset != offs {
|
||||
@ -281,3 +338,47 @@ func TestIllegalChars(t *testing.T) {
|
||||
t.Errorf("found %d errors", s.ErrorCount);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
func TestStdErrorHander(t *testing.T) {
|
||||
const src =
|
||||
"@\n" // illegal character, cause an error
|
||||
"@ @\n" // two errors on the same line
|
||||
"//line File2:20\n"
|
||||
"@\n" // different file, but same line
|
||||
"//line File2:1\n"
|
||||
"@ @\n" // same file, decreasing line number
|
||||
"//line File1:1\n"
|
||||
"@ @ @" // original file, line 1 again
|
||||
;
|
||||
|
||||
var s scanner.Scanner;
|
||||
v := NewErrorVector();
|
||||
nerrors := scanner.Tokenize("File1", strings.Bytes(src), v, 0,
|
||||
func (pos token.Position, tok token.Token, litb []byte) bool {
|
||||
return tok != token.EOF;
|
||||
}
|
||||
);
|
||||
|
||||
list := v.GetErrorList(Raw);
|
||||
if len(list) != 9 {
|
||||
t.Errorf("found %d raw errors, expected 9", len(list));
|
||||
PrintError(os.Stderr, list);
|
||||
}
|
||||
|
||||
list = v.GetErrorList(Sorted);
|
||||
if len(list) != 9 {
|
||||
t.Errorf("found %d sorted errors, expected 9", len(list));
|
||||
PrintError(os.Stderr, list);
|
||||
}
|
||||
|
||||
list = v.GetErrorList(NoMultiples);
|
||||
if len(list) != 4 {
|
||||
t.Errorf("found %d one-per-line errors, expected 4", len(list));
|
||||
PrintError(os.Stderr, list);
|
||||
}
|
||||
|
||||
if v.ErrorCount() != nerrors {
|
||||
t.Errorf("found %d errors, expected %d", v.ErrorCount(), nerrors);
|
||||
}
|
||||
}
|
||||
|
||||
@ -327,6 +327,7 @@ func (tok Token) IsKeyword() bool {
|
||||
// A Position is valid if the line number is > 0.
|
||||
//
|
||||
type Position struct {
|
||||
Filename string; // filename, if any
|
||||
Offset int; // byte offset, starting at 0
|
||||
Line int; // line number, starting at 1
|
||||
Column int; // column number, starting at 1 (character count)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user