extract parser error rendering and token labels

Author: mgomes

vibes/parser.go

@@ -1,26 +1,5 @@
 package vibes
 
-import (
-	"fmt"
-	"strings"
-)
-
-type parseError struct {
-	pos    Position
-	msg    string
-	source string
-}
-
-func (e *parseError) Error() string {
-	var b strings.Builder
-	fmt.Fprintf(&b, "parse error at %d:%d: %s", e.pos.Line, e.pos.Column, e.msg)
-	if frame := formatCodeFrame(e.source, e.pos); frame != "" {
-		b.WriteString("\n")
-		b.WriteString(frame)
-	}
-	return b.String()
-}
-
 type (
 	prefixParseFn func() Expression
 	infixParseFn  func(Expression) Expression
@@ -137,85 +116,3 @@ func (p *parser) expectPeek(tt TokenType) bool {
 	p.errorExpected(p.peekToken, tokenLabel(tt))
 	return false
 }
-
-func (p *parser) errorExpected(tok Token, expected string) {
-	p.addParseError(tok.Pos, fmt.Sprintf("expected %s, got %s", expected, tokenLabel(tok.Type)))
-}
-
-func (p *parser) errorUnexpected(tok Token) {
-	p.addParseError(tok.Pos, fmt.Sprintf("unexpected token %s", tokenLabel(tok.Type)))
-}
-
-func (p *parser) addParseError(pos Position, msg string) {
-	p.errors = append(p.errors, &parseError{pos: pos, msg: msg, source: p.l.input})
-}
-
-func tokenLabel(tt TokenType) string {
-	switch tt {
-	case tokenIllegal:
-		return "invalid token"
-	case tokenEOF:
-		return "end of input"
-	case tokenIdent:
-		return "identifier"
-	case tokenInt:
-		return "integer"
-	case tokenFloat:
-		return "float"
-	case tokenString:
-		return "string"
-	case tokenSymbol:
-		return "symbol"
-	case tokenIvar:
-		return "instance variable"
-	case tokenClassVar:
-		return "class variable"
-	case tokenDef:
-		return "'def'"
-	case tokenClass:
-		return "'class'"
-	case tokenExport:
-		return "'export'"
-	case tokenSelf:
-		return "'self'"
-	case tokenPrivate:
-		return "'private'"
-	case tokenProperty:
-		return "'property'"
-	case tokenGetter:
-		return "'getter'"
-	case tokenSetter:
-		return "'setter'"
-	case tokenEnd:
-		return "'end'"
-	case tokenRaise:
-		return "'raise'"
-	case tokenReturn:
-		return "'return'"
-	case tokenYield:
-		return "'yield'"
-	case tokenDo:
-		return "'do'"
-	case tokenFor:
-		return "'for'"
-	case tokenIn:
-		return "'in'"
-	case tokenIf:
-		return "'if'"
-	case tokenElsif:
-		return "'elsif'"
-	case tokenElse:
-		return "'else'"
-	case tokenTrue:
-		return "'true'"
-	case tokenFalse:
-		return "'false'"
-	case tokenNil:
-		return "'nil'"
-	default:
-		if len(tt) == 1 || strings.HasPrefix(string(tt), "<") || strings.HasPrefix(string(tt), ">") {
-			return fmt.Sprintf("%q", string(tt))
-		}
-		return fmt.Sprintf("%q", strings.ToLower(string(tt)))
-	}
-}

vibes/parser_errors.go

@@ -0,0 +1,104 @@
+package vibes
+
+import (
+	"fmt"
+	"strings"
+)
+
+type parseError struct {
+	pos    Position
+	msg    string
+	source string
+}
+
+func (e *parseError) Error() string {
+	var b strings.Builder
+	fmt.Fprintf(&b, "parse error at %d:%d: %s", e.pos.Line, e.pos.Column, e.msg)
+	if frame := formatCodeFrame(e.source, e.pos); frame != "" {
+		b.WriteString("\n")
+		b.WriteString(frame)
+	}
+	return b.String()
+}
+
+func (p *parser) errorExpected(tok Token, expected string) {
+	p.addParseError(tok.Pos, fmt.Sprintf("expected %s, got %s", expected, tokenLabel(tok.Type)))
+}
+
+func (p *parser) errorUnexpected(tok Token) {
+	p.addParseError(tok.Pos, fmt.Sprintf("unexpected token %s", tokenLabel(tok.Type)))
+}
+
+func (p *parser) addParseError(pos Position, msg string) {
+	p.errors = append(p.errors, &parseError{pos: pos, msg: msg, source: p.l.input})
+}
+
+func tokenLabel(tt TokenType) string {
+	switch tt {
+	case tokenIllegal:
+		return "invalid token"
+	case tokenEOF:
+		return "end of input"
+	case tokenIdent:
+		return "identifier"
+	case tokenInt:
+		return "integer"
+	case tokenFloat:
+		return "float"
+	case tokenString:
+		return "string"
+	case tokenSymbol:
+		return "symbol"
+	case tokenIvar:
+		return "instance variable"
+	case tokenClassVar:
+		return "class variable"
+	case tokenDef:
+		return "'def'"
+	case tokenClass:
+		return "'class'"
+	case tokenExport:
+		return "'export'"
+	case tokenSelf:
+		return "'self'"
+	case tokenPrivate:
+		return "'private'"
+	case tokenProperty:
+		return "'property'"
+	case tokenGetter:
+		return "'getter'"
+	case tokenSetter:
+		return "'setter'"
+	case tokenEnd:
+		return "'end'"
+	case tokenRaise:
+		return "'raise'"
+	case tokenReturn:
+		return "'return'"
+	case tokenYield:
+		return "'yield'"
+	case tokenDo:
+		return "'do'"
+	case tokenFor:
+		return "'for'"
+	case tokenIn:
+		return "'in'"
+	case tokenIf:
+		return "'if'"
+	case tokenElsif:
+		return "'elsif'"
+	case tokenElse:
+		return "'else'"
+	case tokenTrue:
+		return "'true'"
+	case tokenFalse:
+		return "'false'"
+	case tokenNil:
+		return "'nil'"
+	default:
+		if len(tt) == 1 || strings.HasPrefix(string(tt), "<") || strings.HasPrefix(string(tt), ">") {
+			return fmt.Sprintf("%q", string(tt))
+		}
+		return fmt.Sprintf("%q", strings.ToLower(string(tt)))
+	}
+}