func verifyPositions(t *testing.T, fset *token.FileSet, f *token.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)), token.Position{f.Name(), offs, line, col})
checkPos(t, msg, fset.Position(p), token.Position{f.Name(), offs, line, col})
}
}
// Init prepares the scanner S to tokenize the text src by setting the
// scanner at the beginning of src. The scanner uses the file set file
// for position information and it adds line information for each line.
// It is ok to re-use the same file when re-scanning the same file as
// line information which is already present is ignored. Init causes a
// panic if the file size does not match the src size.
//
// Calls to Scan will use the error handler err if they encounter a
// syntax error and err is not nil. Also, for each error encountered,
// the Scanner field ErrorCount is incremented by one. The mode parameter
// determines how comments, illegal characters, and semicolons are handled.
//
// Note that Init may call err if there is an error in the first character
// of the file.
//
func (S *Scanner) Init(file *token.File, src []byte, err ErrorHandler, mode uint) {
// Explicitly initialize all fields since a scanner may be reused.
if file.Size() != len(src) {
panic("file size does not match src len")
}
S.file = file
S.dir, _ = filepath.Split(file.Name())
S.src = src
S.err = err
S.mode = mode
S.ch = ' '
S.offset = 0
S.rdOffset = 0
S.lineOffset = 0
S.insertSemi = false
S.ErrorCount = 0
S.next()
}