Expressions now support function definition

token.go

@@ -11,6 +11,8 @@ import (
 )
 
 type Token struct {
+	row    int
+	col    int
 	Sym    Symbol
 	source string
 	Value  any
@@ -30,19 +32,19 @@ func (tk *Token) String() string {
 	return fmt.Sprintf("%s", tk.source)
 }
 
-func NewToken(sym Symbol, source string) *Token {
-	return &Token{Sym: sym, source: source}
+func NewToken(row, col int, sym Symbol, source string) *Token {
+	return &Token{row: row, col: col, Sym: sym, source: source}
 }
 
-func NewValueToken(sym Symbol, source string, value any) *Token {
-	return &Token{Sym: sym, source: source, Value: value}
+func NewValueToken(row, col int, sym Symbol, source string, value any) *Token {
+	return &Token{row: row, col: col, Sym: sym, source: source, Value: value}
 }
 
 func NewErrorToken(row, col int, err error) *Token {
 	if err == io.EOF {
-		return NewToken(SymEos, "")
+		return NewToken(row, col, SymEos, "")
 	}
-	return NewValueToken(SymError, fmt.Sprintf("[%d:%d]", row, col), err)
+	return NewValueToken(row, col, SymError, fmt.Sprintf("[%d:%d]", row, col), err)
 }
 
 func (tk *Token) IsEos() bool {
@@ -56,3 +58,8 @@ func (tk *Token) IsError() bool {
 func (tk *Token) IsTerm(termSymbols []Symbol) bool {
 	return tk.IsEos() || tk.IsError() || (termSymbols != nil && slices.Index(termSymbols, tk.Sym) >= 0)
 }
+
+func (self *Token) Errorf(template string, args ...any) (err error) {
+	err = fmt.Errorf(fmt.Sprintf("[%d:%d] ", self.row, self.col)+template, args...)
+	return
+}