func newLexer(nm string, sz int, r io.RuneReader, report *xc.Report) (*lexer, error) { file := xc.FileSet.AddFile(nm, -1, sz+2) lx, err := lex.New( file, r, lex.ErrorFunc(func(pos token.Pos, msg string) { report.Err(pos, msg) }), lex.RuneClass(func(r rune) int { return int(r) }), ) if err != nil { return nil, err } l := &lexer{ Lexer: lx, report: report, } l.emit(&Call{Target: 2}) l.emit(&Halt{}) l.enter = &Enter{NVars: -1} l.jmp = &Jmp{Target: -1} l.emit(l.enter) l.emit(l.jmp) return l, nil }