Add ParseParameter. Also fell down the rabbithole improving content and consistency of parse errors

error_formatter.go

@@ -69,7 +69,7 @@ func (ef *termErrorFormatter) Format(err error) string {
 	case RuntimeError:
 		return ef.formatRuntime(&err)
 	case errors.StaticError:
-		return ef.formatStatic(&err)
+		return ef.formatStatic(err)
 	default:
 		return ef.formatInternal(err)
 	}
@@ -79,10 +79,10 @@ func (ef *termErrorFormatter) formatRuntime(err *RuntimeError) string {
 	return err.Error() + "\n" + ef.buildStackTrace(err.StackTrace)
 }
 
-func (ef *termErrorFormatter) formatStatic(err *errors.StaticError) string {
+func (ef *termErrorFormatter) formatStatic(err errors.StaticError) string {
 	var buf bytes.Buffer
 	buf.WriteString(err.Error() + "\n")
-	ef.showCode(&buf, err.Loc)
+	ef.showCode(&buf, err.Loc())
 	return buf.String()
 }
 

internal/errors/static_error.go

@@ -27,26 +27,45 @@ import (
 
 // StaticError represents an error during parsing/lexing or static analysis.
 // TODO(sbarzowski) Make it possible to have multiple static errors and warnings
-type StaticError struct {
-	Loc ast.LocationRange
-	Msg string
+type StaticError interface {
+	// WithContext returns a new StaticError with additional context before the error message.
+	WithContext(string) StaticError
+	// Error returns the string representation of a StaticError.
+	Error() string
+	// Loc returns the place in the source code that triggerred the error.
+	Loc() ast.LocationRange
 }
 
-// MakeStaticErrorMsg returns a StaticError with a message.
+type staticError struct {
+	loc ast.LocationRange
+	msg string
+}
+
+func (err staticError) WithContext(context string) StaticError {
+	return staticError{
+		loc: err.loc,
+		msg: fmt.Sprintf("%v while %s", err.msg, context),
+	}
+}
+
+func (err staticError) Error() string {
+	loc := ""
+	if err.loc.IsSet() {
+		loc = err.loc.String()
+	}
+	return fmt.Sprintf("%v %v", loc, err.msg)
+}
+
+func (err staticError) Loc() ast.LocationRange {
+	return err.loc
+}
+
+// MakeStaticErrorMsg returns a staticError with a message.
 func MakeStaticErrorMsg(msg string) StaticError {
-	return StaticError{Msg: msg}
+	return staticError{msg: msg}
 }
 
 // MakeStaticError returns a StaticError with a message and a LocationRange.
 func MakeStaticError(msg string, lr ast.LocationRange) StaticError {
-	return StaticError{Msg: msg, Loc: lr}
-}
-
-// Error returns the string representation of a StaticError.
-func (err StaticError) Error() string {
-	loc := ""
-	if err.Loc.IsSet() {
-		loc = err.Loc.String()
-	}
-	return fmt.Sprintf("%v %v", loc, err.Msg)
+	return staticError{msg: msg, loc: lr}
 }

internal/parser/lexer.go

@@ -126,6 +126,17 @@ var tokenKindStrings = []string{
 	tokenEndOfFile: "end of file",
 }
 
+var tokenHasContent = map[tokenKind]bool{
+	tokenIdentifier:           true,
+	tokenNumber:               true,
+	tokenOperator:             true,
+	tokenStringBlock:          true,
+	tokenStringDouble:         true,
+	tokenStringSingle:         true,
+	tokenVerbatimStringDouble: true,
+	tokenVerbatimStringSingle: true,
+}
+
 func (tk tokenKind) String() string {
 	if tk < 0 || int(tk) >= len(tokenKindStrings) {
 		panic(fmt.Sprintf("INTERNAL ERROR: Unknown token kind:: %d", tk))
@@ -151,10 +162,10 @@ type Tokens []token
 func (t *token) String() string {
 	if t.data == "" {
 		return t.kind.String()
-	} else if t.kind == tokenOperator {
-		return fmt.Sprintf("\"%v\"", t.data)
-	} else {
+	} else if tokenHasContent[t.kind] {
 		return fmt.Sprintf("(%v, \"%v\")", t.kind, t.data)
+	} else {
+		return fmt.Sprintf("\"%v\"", t.data)
 	}
 }
 
@@ -387,7 +398,7 @@ func (l *lexer) addFodder(kind ast.FodderKind, blanks int, indent int, comment [
 }
 
 func (l *lexer) makeStaticErrorPoint(msg string, loc ast.Location) errors.StaticError {
-	return errors.StaticError{Msg: msg, Loc: ast.MakeLocationRange(l.fileName, l.source, loc, loc)}
+	return errors.MakeStaticError(msg, ast.MakeLocationRange(l.fileName, l.source, loc, loc))
 }
 
 // lexWhitespace consumes all whitespace and returns the number of \n and number of

internal/parser/parser.go

@@ -56,9 +56,9 @@ var bopPrecedence = map[ast.BinaryOp]precedence{
 
 // ---------------------------------------------------------------------------
 
-func makeUnexpectedError(t *token, while string) error {
+func makeUnexpectedError(t *token, while string) errors.StaticError {
 	return errors.MakeStaticError(
-		fmt.Sprintf("Unexpected: %v while %v", t, while), t.loc)
+		fmt.Sprintf("Unexpected: %v", t), t.loc).WithContext(while)
 }
 
 func locFromTokens(begin, end *token) ast.LocationRange {
@@ -88,14 +88,14 @@ func (p *parser) pop() *token {
 	return t
 }
 
-func (p *parser) unexpectedTokenError(tk tokenKind, t *token) error {
+func (p *parser) unexpectedTokenError(tk tokenKind, t *token) errors.StaticError {
 	if tk == t.kind {
-		panic("Unexpectedly expected token kind.")
+		panic("Unexpectedly expected token kind")
 	}
 	return errors.MakeStaticError(fmt.Sprintf("Expected token %v but got %v", tk, t), t.loc)
 }
 
-func (p *parser) popExpect(tk tokenKind) (*token, error) {
+func (p *parser) popExpect(tk tokenKind) (*token, errors.StaticError) {
 	t := p.pop()
 	if t.kind != tk {
 		return nil, p.unexpectedTokenError(tk, t)
@@ -103,7 +103,7 @@ func (p *parser) popExpect(tk tokenKind) (*token, error) {
 	return t, nil
 }
 
-func (p *parser) popExpectOp(op string) (*token, error) {
+func (p *parser) popExpectOp(op string) (*token, errors.StaticError) {
 	t := p.pop()
 	if t.kind != tokenOperator || t.data != op {
 		return nil, errors.MakeStaticError(
@@ -133,7 +133,7 @@ func astVarToIdentifier(node ast.Node) (ast.Fodder, *ast.Identifier, bool) {
 // parseArgument parses either <f1> id <f2> = expr or just expr.
 // It returns either (<f1>, id, <f2>, expr) or (nil, nil, nil, expr)
 // respectively.
-func (p *parser) parseArgument() (ast.Fodder, *ast.Identifier, ast.Fodder, ast.Node, error) {
+func (p *parser) parseArgument() (ast.Fodder, *ast.Identifier, ast.Fodder, ast.Node, errors.StaticError) {
 	var idFodder ast.Fodder
 	var id *ast.Identifier
 	var eqFodder ast.Fodder
@@ -153,7 +153,7 @@ func (p *parser) parseArgument() (ast.Fodder, *ast.Identifier, ast.Fodder, ast.N
 }
 
 // TODO(sbarzowski) - this returned bool is weird
-func (p *parser) parseArguments(elementKind string) (*token, *ast.Arguments, bool, error) {
+func (p *parser) parseArguments(elementKind string) (*token, *ast.Arguments, bool, errors.StaticError) {
 	args := &ast.Arguments{}
 	gotComma := false
 	commaFodder := ast.Fodder{}
@@ -168,7 +168,7 @@ func (p *parser) parseArguments(elementKind string) (*token, *ast.Arguments, boo
 		}
 
 		if !first && !gotComma {
-			return nil, nil, false, errors.MakeStaticError(fmt.Sprintf("Expected a comma before next %s, got %s.", elementKind, next), next.loc)
+			return nil, nil, false, errors.MakeStaticError(fmt.Sprintf("Expected a comma before next %s, got %s", elementKind, next), next.loc)
 		}
 
 		idFodder, id, eqFodder, expr, err := p.parseArgument()
@@ -208,8 +208,34 @@ func (p *parser) parseArguments(elementKind string) (*token, *ast.Arguments, boo
 	}
 }
 
+// parseParameter parses either <f1> id <f2> = expr or just <f1> id.
+// It returns either (<f1>, id, <f2>, expr) or (<f1>, id, nil, nil)
+// respectively.
+func (p *parser) parseParameter() (ast.Fodder, *ast.Identifier, ast.Fodder, ast.Node, errors.StaticError) {
+	var idFodder ast.Fodder
+	var id *ast.Identifier
+	var eqFodder ast.Fodder
+	ident, err := p.popExpect(tokenIdentifier)
+	if err != nil {
+		return nil, nil, nil, nil, err.WithContext("parsing parameter")
+	}
+	var tmpID = ast.Identifier(ident.data)
+	id = &tmpID
+	idFodder = ident.fodder
+	if p.peek().kind == tokenOperator && p.peek().data == "=" {
+		eq := p.pop()
+		eqFodder = eq.fodder
+		expr, err := p.parse(maxPrecedence)
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		return idFodder, id, eqFodder, expr, nil
+	}
+	return idFodder, id, nil, nil, nil
+}
+
 // TODO(sbarzowski) - this returned bool is weird
-func (p *parser) parseParameters(elementKind string) (*token, []ast.Parameter, bool, error) {
+func (p *parser) parseParameters(elementKind string) (*token, []ast.Parameter, bool, errors.StaticError) {
 
 	var parenR *token
 	var params []ast.Parameter
@@ -226,10 +252,10 @@ func (p *parser) parseParameters(elementKind string) (*token, []ast.Parameter, b
 		}
 
 		if !first && !gotComma {
-			return nil, nil, false, errors.MakeStaticError(fmt.Sprintf("Expected a comma before next %s, got %s.", elementKind, next), next.loc)
+			return nil, nil, false, errors.MakeStaticError(fmt.Sprintf("Expected a comma before next %s, got %s", elementKind, next), next.loc)
 		}
 
-		idFodder, id, eqFodder, expr, err := p.parseArgument()
+		idFodder, id, eqFodder, expr, err := p.parseParameter()
 		if err != nil {
 			return nil, nil, false, err
 		}
@@ -242,15 +268,11 @@ func (p *parser) parseParameters(elementKind string) (*token, []ast.Parameter, b
 			gotComma = false
 		}
 
-		if id == nil {
-			// Param has no default, is just 'id2'
-			idFodder2, id2, ok := astVarToIdentifier(expr)
-			if !ok {
-				return nil, nil, false, errors.MakeStaticError(fmt.Sprintf("Expected simple identifier but got a complex expression."), *expr.Loc())
-			}
+		if expr == nil {
+			// Param has no default
 			param := ast.Parameter{
-				NameFodder: idFodder2,
-				Name:       *id2,
+				NameFodder: idFodder,
+				Name:       *id,
 			}
 			if gotComma {
 				param.CommaFodder = commaFodder
@@ -274,10 +296,10 @@ func (p *parser) parseParameters(elementKind string) (*token, []ast.Parameter, b
 }
 
 // TODO(sbarzowski) add location to all individual binds
-func (p *parser) parseBind(binds *ast.LocalBinds) (*token, error) {
-	varID, err := p.popExpect(tokenIdentifier)
-	if err != nil {
-		return nil, err
+func (p *parser) parseBind(binds *ast.LocalBinds) (*token, errors.StaticError) {
+	varID, popErr := p.popExpect(tokenIdentifier)
+	if popErr != nil {
+		return nil, popErr
 	}
 	for _, b := range *binds {
 		if b.Variable == ast.Identifier(varID.data) {
@@ -301,9 +323,9 @@ func (p *parser) parseBind(binds *ast.LocalBinds) (*token, error) {
 		}
 	}
 
-	eqToken, err := p.popExpectOp("=")
-	if err != nil {
-		return nil, err
+	eqToken, popErr := p.popExpectOp("=")
+	if popErr != nil {
+		return nil, popErr
 	}
 	body, err := p.parse(maxPrecedence)
 	if err != nil {
@@ -339,7 +361,7 @@ func (p *parser) parseBind(binds *ast.LocalBinds) (*token, error) {
 	return delim, nil
 }
 
-func (p *parser) parseObjectAssignmentOp() (opFodder ast.Fodder, plusSugar bool, hide ast.ObjectFieldHide, err error) {
+func (p *parser) parseObjectAssignmentOp() (opFodder ast.Fodder, plusSugar bool, hide ast.ObjectFieldHide, err errors.StaticError) {
 	op, err := p.popExpect(tokenOperator)
 	if err != nil {
 		return
@@ -382,7 +404,7 @@ func (p *parser) parseObjectAssignmentOp() (opFodder ast.Fodder, plusSugar bool,
 // +gen set
 type LiteralField string
 
-func (p *parser) parseObjectRemainderComp(fields ast.ObjectFields, gotComma bool, tok *token, next *token) (ast.Node, *token, error) {
+func (p *parser) parseObjectRemainderComp(fields ast.ObjectFields, gotComma bool, tok *token, next *token) (ast.Node, *token, errors.StaticError) {
 	numFields := 0
 	numAsserts := 0
 	var field ast.ObjectField
@@ -399,16 +421,16 @@ func (p *parser) parseObjectRemainderComp(fields ast.ObjectFields, gotComma bool
 	}
 
 	if numAsserts > 0 {
-		return nil, nil, errors.MakeStaticError("Object comprehension cannot have asserts.", next.loc)
+		return nil, nil, errors.MakeStaticError("Object comprehension cannot have asserts", next.loc)
 	}
 	if numFields != 1 {
-		return nil, nil, errors.MakeStaticError("Object comprehension can only have one field.", next.loc)
+		return nil, nil, errors.MakeStaticError("Object comprehension can only have one field", next.loc)
 	}
 	if field.Hide != ast.ObjectFieldInherit {
-		return nil, nil, errors.MakeStaticError("Object comprehensions cannot have hidden fields.", next.loc)
+		return nil, nil, errors.MakeStaticError("Object comprehensions cannot have hidden fields", next.loc)
 	}
 	if field.Kind != ast.ObjectFieldExpr {
-		return nil, nil, errors.MakeStaticError("Object comprehensions can only have [e] fields.", next.loc)
+		return nil, nil, errors.MakeStaticError("Object comprehensions can only have [e] fields", next.loc)
 	}
 	spec, last, err := p.parseComprehensionSpecs(next, tokenBraceR)
 	if err != nil {
@@ -423,7 +445,7 @@ func (p *parser) parseObjectRemainderComp(fields ast.ObjectFields, gotComma bool
 	}, last, nil
 }
 
-func (p *parser) parseObjectRemainderField(literalFields *LiteralFieldSet, tok *token, next *token) (*ast.ObjectField, error) {
+func (p *parser) parseObjectRemainderField(literalFields *LiteralFieldSet, tok *token, next *token) (*ast.ObjectField, errors.StaticError) {
 	var kind ast.ObjectFieldKind
 	var fodder1 ast.Fodder
 	var expr1 ast.Node
@@ -441,7 +463,7 @@ func (p *parser) parseObjectRemainderField(literalFields *LiteralFieldSet, tok *
 	default:
 		fodder1 = next.fodder
 		kind = ast.ObjectFieldExpr
-		var err error
+		var err errors.StaticError
 		expr1, err = p.parse(maxPrecedence)
 		if err != nil {
 			return nil, err
@@ -460,7 +482,7 @@ func (p *parser) parseObjectRemainderField(literalFields *LiteralFieldSet, tok *
 	var params []ast.Parameter
 	if p.peek().kind == tokenParenL {
 		parenL = p.pop()
-		var err error
+		var err errors.StaticError
 		parenR, params, methComma, err = p.parseParameters("method parameter")
 		if err != nil {
 			return nil, err
@@ -521,10 +543,10 @@ func (p *parser) parseObjectRemainderField(literalFields *LiteralFieldSet, tok *
 	}, nil
 }
 
-func (p *parser) parseObjectRemainderLocal(binds *ast.IdentifierSet, tok *token, next *token) (*ast.ObjectField, error) {
-	varID, err := p.popExpect(tokenIdentifier)
-	if err != nil {
-		return nil, err
+func (p *parser) parseObjectRemainderLocal(binds *ast.IdentifierSet, tok *token, next *token) (*ast.ObjectField, errors.StaticError) {
+	varID, popErr := p.popExpect(tokenIdentifier)
+	if popErr != nil {
+		return nil, popErr
 	}
 
 	id := ast.Identifier(varID.data)
@@ -543,14 +565,15 @@ func (p *parser) parseObjectRemainderLocal(binds *ast.IdentifierSet, tok *token,
 	if p.peek().kind == tokenParenL {
 		parenL = p.pop()
 		isMethod = true
+		var err errors.StaticError
 		parenR, params, funcComma, err = p.parseParameters("function parameter")
 		if err != nil {
 			return nil, err
 		}
 	}
-	opToken, err := p.popExpectOp("=")
-	if err != nil {
-		return nil, err
+	opToken, popErr := p.popExpectOp("=")
+	if popErr != nil {
+		return nil, popErr
 	}
 
 	body, err := p.parse(maxPrecedence)
@@ -590,7 +613,7 @@ func (p *parser) parseObjectRemainderLocal(binds *ast.IdentifierSet, tok *token,
 	}, nil
 }
 
-func (p *parser) parseObjectRemainderAssert(tok *token, next *token) (*ast.ObjectField, error) {
+func (p *parser) parseObjectRemainderAssert(tok *token, next *token) (*ast.ObjectField, errors.StaticError) {
 	cond, err := p.parse(maxPrecedence)
 	if err != nil {
 		return nil, err
@@ -623,7 +646,7 @@ func (p *parser) parseObjectRemainderAssert(tok *token, next *token) (*ast.Objec
 }
 
 // Parse object or object comprehension without leading brace
-func (p *parser) parseObjectRemainder(tok *token) (ast.Node, *token, error) {
+func (p *parser) parseObjectRemainder(tok *token) (ast.Node, *token, errors.StaticError) {
 	var fields ast.ObjectFields
 	literalFields := make(LiteralFieldSet)
 	binds := make(ast.IdentifierSet)
@@ -650,11 +673,11 @@ func (p *parser) parseObjectRemainder(tok *token) (ast.Node, *token, error) {
 		}
 
 		if !gotComma && !first {
-			return nil, nil, errors.MakeStaticError("Expected a comma before next field.", next.loc)
+			return nil, nil, errors.MakeStaticError("Expected a comma before next field", next.loc)
 		}
 
 		var field *ast.ObjectField
-		var err error
+		var err errors.StaticError
 		switch next.kind {
 		case tokenBracketL, tokenIdentifier, tokenStringDouble, tokenStringSingle,
 			tokenStringBlock, tokenVerbatimStringDouble, tokenVerbatimStringSingle:
@@ -693,14 +716,14 @@ func (p *parser) parseObjectRemainder(tok *token) (ast.Node, *token, error) {
 }
 
 /* parses for x in expr for y in expr if expr for z in expr ... */
-func (p *parser) parseComprehensionSpecs(forToken *token, end tokenKind) (*ast.ForSpec, *token, error) {
-	var parseComprehensionSpecsHelper func(forToken *token, outer *ast.ForSpec) (*ast.ForSpec, *token, error)
-	parseComprehensionSpecsHelper = func(forToken *token, outer *ast.ForSpec) (*ast.ForSpec, *token, error) {
+func (p *parser) parseComprehensionSpecs(forToken *token, end tokenKind) (*ast.ForSpec, *token, errors.StaticError) {
+	var parseComprehensionSpecsHelper func(forToken *token, outer *ast.ForSpec) (*ast.ForSpec, *token, errors.StaticError)
+	parseComprehensionSpecsHelper = func(forToken *token, outer *ast.ForSpec) (*ast.ForSpec, *token, errors.StaticError) {
 		var ifSpecs []ast.IfSpec
 
-		varID, err := p.popExpect(tokenIdentifier)
-		if err != nil {
-			return nil, nil, err
+		varID, popErr := p.popExpect(tokenIdentifier)
+		if popErr != nil {
+			return nil, nil, popErr
 		}
 		id := ast.Identifier(varID.data)
 		inToken, err := p.popExpect(tokenIn)
@@ -748,7 +771,7 @@ func (p *parser) parseComprehensionSpecs(forToken *token, end tokenKind) (*ast.F
 
 // Assumes that the leading '[' has already been consumed and passed as tok.
 // Should read up to and consume the trailing ']'
-func (p *parser) parseArray(tok *token) (ast.Node, error) {
+func (p *parser) parseArray(tok *token) (ast.Node, errors.StaticError) {
 	if p.peek().kind == tokenBracketR {
 		bracketR := p.pop()
 		return &ast.Array{
@@ -801,7 +824,7 @@ func (p *parser) parseArray(tok *token) (ast.Node, error) {
 			break
 		}
 		if !gotComma {
-			return nil, errors.MakeStaticError("Expected a comma before next array element.", next.loc)
+			return nil, errors.MakeStaticError("Expected a comma before next array element", next.loc)
 		}
 		nextElem, err := p.parse(maxPrecedence)
 		if err != nil {
@@ -868,7 +891,7 @@ func tokenStringToAst(tok *token) *ast.LiteralString {
 	}
 }
 
-func (p *parser) parseTerminal() (ast.Node, error) {
+func (p *parser) parseTerminal() (ast.Node, errors.StaticError) {
 	tok := p.pop()
 	switch tok.kind {
 	case tokenAssert, tokenBraceR, tokenBracketR, tokenComma, tokenDot, tokenElse,
@@ -877,7 +900,7 @@ func (p *parser) parseTerminal() (ast.Node, error) {
 		return nil, makeUnexpectedError(tok, "parsing terminal")
 
 	case tokenEndOfFile:
-		return nil, errors.MakeStaticError("Unexpected end of file.", tok.loc)
+		return nil, errors.MakeStaticError("Unexpected end of file", tok.loc)
 
 	case tokenBraceL:
 		obj, _, err := p.parseObjectRemainder(tok)
@@ -953,7 +976,7 @@ func (p *parser) parseTerminal() (ast.Node, error) {
 			idFodder = fieldID.fodder
 			id = (*ast.Identifier)(&fieldID.data)
 		case tokenBracketL:
-			var err error
+			var err errors.StaticError
 			index, err = p.parse(maxPrecedence)
 			if err != nil {
 				return nil, err
@@ -964,7 +987,7 @@ func (p *parser) parseTerminal() (ast.Node, error) {
 			}
 			idFodder = bracketR.fodder
 		default:
-			return nil, errors.MakeStaticError("Expected . or [ after super.", tok.loc)
+			return nil, errors.MakeStaticError("Expected . or [ after super", tok.loc)
 		}
 		return &ast.SuperIndex{
 			NodeBase:  ast.NewNodeBaseLoc(tok.loc, tok.fodder),
@@ -978,11 +1001,11 @@ func (p *parser) parseTerminal() (ast.Node, error) {
 	return nil, errors.MakeStaticError(fmt.Sprintf("INTERNAL ERROR: Unknown tok kind: %v", tok.kind), tok.loc)
 }
 
-func (p *parser) parsingFailure(msg string, tok *token) (ast.Node, error) {
+func (p *parser) parsingFailure(msg string, tok *token) (ast.Node, errors.StaticError) {
 	return nil, errors.MakeStaticError(msg, tok.loc)
 }
 
-func (p *parser) parse(prec precedence) (ast.Node, error) {
+func (p *parser) parse(prec precedence) (ast.Node, errors.StaticError) {
 	begin := p.peek()
 
 	switch begin.kind {
@@ -1365,7 +1388,7 @@ func (p *parser) parse(prec precedence) (ast.Node, error) {
 // ---------------------------------------------------------------------------
 
 // Parse parses a slice of tokens into a parse tree.
-func Parse(t Tokens) (ast.Node, error) {
+func Parse(t Tokens) (ast.Node, errors.StaticError) {
 	p := makeParser(t)
 	expr, err := p.parse(maxPrecedence)
 	if err != nil {

internal/parser/parser_test.go

@@ -146,74 +146,74 @@ type testError struct {
 }
 
 var errorTests = []testError{
-	{`,`, `test:1:1-2 Unexpected: (",", ",") while parsing terminal`},
-	{`function(a, b c)`, `test:1:15-16 Expected a comma before next function parameter, got (IDENTIFIER, "c").`},
-	{`function(a, 1)`, `test:1:13-14 Expected simple identifier but got a complex expression.`},
-	{`function(,)`, `test:1:10-11 Unexpected: (",", ",") while parsing terminal`},
-	{`function(a=)`, `test:1:12-13 Unexpected: (")", ")") while parsing terminal`},
-	{`function(a=,)`, `test:1:12-13 Unexpected: (",", ",") while parsing terminal`},
+	{`,`, `test:1:1-2 Unexpected: "," while parsing terminal`},
+	{`function(a, b c)`, `test:1:15-16 Expected a comma before next function parameter, got (IDENTIFIER, "c")`},
+	{`function(a, 1)`, `test:1:13-14 Expected token IDENTIFIER but got (NUMBER, "1") while parsing parameter`},
+	{`function(,)`, `test:1:10-11 Expected token IDENTIFIER but got "," while parsing parameter`},
+	{`function(a=)`, `test:1:12-13 Unexpected: ")" while parsing terminal`},
+	{`function(a=,)`, `test:1:12-13 Unexpected: "," while parsing terminal`},
 	{`a b`, `test:1:3-4 Did not expect: (IDENTIFIER, "b")`},
-	{`foo(a, bar(a b))`, `test:1:14-15 Expected a comma before next function argument, got (IDENTIFIER, "b").`},
+	{`foo(a, bar(a b))`, `test:1:14-15 Expected a comma before next function argument, got (IDENTIFIER, "b")`},
 
 	{`local`, `test:1:6 Expected token IDENTIFIER but got end of file`},
 	{`local foo = 1, foo = 2; true`, `test:1:16-19 Duplicate local var: foo`},
-	{`local foo(a b) = a; true`, `test:1:13-14 Expected a comma before next function parameter, got (IDENTIFIER, "b").`},
-	{`local foo(a): a; true`, `test:1:13-14 Expected operator = but got ":"`},
-	{`local foo(a) = bar(a b); true`, `test:1:22-23 Expected a comma before next function argument, got (IDENTIFIER, "b").`},
-	{`local foo: 1; true`, `test:1:10-11 Expected operator = but got ":"`},
-	{`local foo = bar(a b); true`, `test:1:19-20 Expected a comma before next function argument, got (IDENTIFIER, "b").`},
+	{`local foo(a b) = a; true`, `test:1:13-14 Expected a comma before next function parameter, got (IDENTIFIER, "b")`},
+	{`local foo(a): a; true`, `test:1:13-14 Expected operator = but got (OPERATOR, ":")`},
+	{`local foo(a) = bar(a b); true`, `test:1:22-23 Expected a comma before next function argument, got (IDENTIFIER, "b")`},
+	{`local foo: 1; true`, `test:1:10-11 Expected operator = but got (OPERATOR, ":")`},
+	{`local foo = bar(a b); true`, `test:1:19-20 Expected a comma before next function argument, got (IDENTIFIER, "b")`},
 
 	{`{a b}`, `test:1:4-5 Expected token OPERATOR but got (IDENTIFIER, "b")`},
 	{`{a = b}`, `test:1:4-5 Expected one of :, ::, :::, +:, +::, +:::, got: =`},
 	{`{a :::: b}`, `test:1:4-8 Expected one of :, ::, :::, +:, +::, +:::, got: ::::`},
 
-	{`{assert x for x in [1, 2, 3]}`, `test:1:11-14 Object comprehension cannot have asserts.`},
-	{`{['foo' + x]: true, [x]: x for x in [1, 2, 3]}`, `test:1:28-31 Object comprehension can only have one field.`},
-	{`{foo: x for x in [1, 2, 3]}`, `test:1:9-12 Object comprehensions can only have [e] fields.`},
-	{`{[x]:: true for x in [1, 2, 3]}`, `test:1:13-16 Object comprehensions cannot have hidden fields.`},
+	{`{assert x for x in [1, 2, 3]}`, `test:1:11-14 Object comprehension cannot have asserts`},
+	{`{['foo' + x]: true, [x]: x for x in [1, 2, 3]}`, `test:1:28-31 Object comprehension can only have one field`},
+	{`{foo: x for x in [1, 2, 3]}`, `test:1:9-12 Object comprehensions can only have [e] fields`},
+	{`{[x]:: true for x in [1, 2, 3]}`, `test:1:13-16 Object comprehensions cannot have hidden fields`},
 	{`{[x]: true for 1 in [1, 2, 3]}`, `test:1:16-17 Expected token IDENTIFIER but got (NUMBER, "1")`},
 	{`{[x]: true for x at [1, 2, 3]}`, `test:1:18-20 Expected token in but got (IDENTIFIER, "at")`},
-	{`{[x]: true for x in [1, 2 3]}`, `test:1:27-28 Expected a comma before next array element.`},
+	{`{[x]: true for x in [1, 2 3]}`, `test:1:27-28 Expected a comma before next array element`},
 	{`{[x]: true for x in [1, 2, 3] if (a b)}`, `test:1:37-38 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`{[x]: true for x in [1, 2, 3] if a b}`, `test:1:36-37 Expected for, if or "}" after for clause, got: (IDENTIFIER, "b")`},
 
-	{`{a: b c:d}`, `test:1:7-8 Expected a comma before next field.`},
+	{`{a: b c:d}`, `test:1:7-8 Expected a comma before next field`},
 
 	{`{[(x y)]: z}`, `test:1:6-7 Expected token ")" but got (IDENTIFIER, "y")`},
 	{`{[x y]: z}`, `test:1:5-6 Expected token "]" but got (IDENTIFIER, "y")`},
 
-	{`{foo(x y): z}`, `test:1:8-9 Expected a comma before next method parameter, got (IDENTIFIER, "y").`},
+	{`{foo(x y): z}`, `test:1:8-9 Expected a comma before next method parameter, got (IDENTIFIER, "y")`},
 	{`{foo(x)+: z}`, `test:1:2-5 Cannot use +: syntax sugar in a method: foo`},
 	{`{foo: 1, foo: 2}`, `test:1:10-13 Duplicate field: foo`},
 	{`{foo: (1 2)}`, `test:1:10-11 Expected token ")" but got (NUMBER, "2")`},
 
 	{`{local 1 = 3, true}`, `test:1:8-9 Expected token IDENTIFIER but got (NUMBER, "1")`},
 	{`{local foo = 1, local foo = 2, true}`, `test:1:23-26 Duplicate local var: foo`},
-	{`{local foo(a b) = 1, a: true}`, `test:1:14-15 Expected a comma before next function parameter, got (IDENTIFIER, "b").`},
-	{`{local foo(a): 1, a: true}`, `test:1:14-15 Expected operator = but got ":"`},
+	{`{local foo(a b) = 1, a: true}`, `test:1:14-15 Expected a comma before next function parameter, got (IDENTIFIER, "b")`},
+	{`{local foo(a): 1, a: true}`, `test:1:14-15 Expected operator = but got (OPERATOR, ":")`},
 	{`{local foo(a) = (a b), a: true}`, `test:1:20-21 Expected token ")" but got (IDENTIFIER, "b")`},
 
 	{`{assert (a b), a: true}`, `test:1:12-13 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`{assert a: (a b), a: true}`, `test:1:15-16 Expected token ")" but got (IDENTIFIER, "b")`},
 
-	{`{function(a, b) a+b: true}`, `test:1:2-10 Unexpected: (function, "function") while parsing field definition`},
+	{`{function(a, b) a+b: true}`, `test:1:2-10 Unexpected: "function" while parsing field definition`},
 
 	{`[(a b), 2, 3]`, `test:1:5-6 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`[1, (a b), 2, 3]`, `test:1:8-9 Expected token ")" but got (IDENTIFIER, "b")`},
-	{`[a for b in [1 2 3]]`, `test:1:16-17 Expected a comma before next array element.`},
+	{`[a for b in [1 2 3]]`, `test:1:16-17 Expected a comma before next array element`},
 
-	{`for`, `test:1:1-4 Unexpected: (for, "for") while parsing terminal`},
-	{``, `test:1:1 Unexpected end of file.`},
+	{`for`, `test:1:1-4 Unexpected: "for" while parsing terminal`},
+	{``, `test:1:1 Unexpected end of file`},
 	{`((a b))`, `test:1:5-6 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`a.1`, `test:1:3-4 Expected token IDENTIFIER but got (NUMBER, "1")`},
 	{`super.1`, `test:1:7-8 Expected token IDENTIFIER but got (NUMBER, "1")`},
 	{`super[(a b)]`, `test:1:10-11 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`super[a b]`, `test:1:9-10 Expected token "]" but got (IDENTIFIER, "b")`},
-	{`super`, `test:1:1-6 Expected . or [ after super.`},
+	{`super`, `test:1:1-6 Expected . or [ after super`},
 
 	{`assert (a b); true`, `test:1:11-12 Expected token ")" but got (IDENTIFIER, "b")`},
 	{`assert a: (a b); true`, `test:1:14-15 Expected token ")" but got (IDENTIFIER, "b")`},
-	{`assert a: 'foo', true`, `test:1:16-17 Expected token ";" but got (",", ",")`},
+	{`assert a: 'foo', true`, `test:1:16-17 Expected token ";" but got ","`},
 	{`assert a: 'foo'; (a b)`, `test:1:21-22 Expected token ")" but got (IDENTIFIER, "b")`},
 
 	{`error (a b)`, `test:1:10-11 Expected token ")" but got (IDENTIFIER, "b")`},

main_test.go

@@ -137,10 +137,10 @@ func runInternalJsonnet(i jsonnetInput) jsonnetResult {
 	vm.NativeFunction(jsonToString)
 	vm.NativeFunction(nativeError)
 
-	rawAST, err := parser.SnippetToRawAST(i.name, string(i.input))
-	if err != nil {
+	rawAST, staticErr := parser.SnippetToRawAST(i.name, string(i.input))
+	if staticErr != nil {
 		return jsonnetResult{
-			output:  errFormatter.Format(err) + "\n",
+			output:  errFormatter.Format(staticErr) + "\n",
 			isError: true,
 		}
 	}

testdata/extvar_static_error.golden

@@ -1,4 +1,4 @@
-<extvar:staticErrorVar>:1:1-2 Unexpected: (")", ")") while parsing terminal
+<extvar:staticErrorVar>:1:1-2 Unexpected: ")" while parsing terminal
 
 )
 

testdata/object_comp_assert.golden

@@ -1,4 +1,4 @@
-testdata/object_comp_assert:1:32-35 Object comprehension cannot have asserts.
+testdata/object_comp_assert:1:32-35 Object comprehension cannot have asserts
 
 { assert self.x == 5, ["x"]: 5 for i in [42] }
 

testdata/object_comp_bad_field.golden

@@ -1,4 +1,4 @@
-testdata/object_comp_bad_field:1:9-12 Object comprehensions can only have [e] fields.
+testdata/object_comp_bad_field:1:9-12 Object comprehensions can only have [e] fields
 
 { x: 42 for _ in [1] }
 

testdata/object_comp_bad_field2.golden

@@ -1,4 +1,4 @@
-testdata/object_comp_bad_field2:1:11-14 Object comprehensions can only have [e] fields.
+testdata/object_comp_bad_field2:1:11-14 Object comprehensions can only have [e] fields
 
 { "x": 42 for _ in [1] }
 

testdata/object_comp_illegal.golden

@@ -1,4 +1,4 @@
-testdata/object_comp_illegal:1:15-18 Object comprehension can only have one field.
+testdata/object_comp_illegal:1:15-18 Object comprehension can only have one field
 
 { local x = 5 for y in [1, 2, 3] }
 

testdata/unfinished_args.golden

@@ -1,4 +1,4 @@
-testdata/unfinished_args:2:1 Expected a comma before next function argument, got end of file.
+testdata/unfinished_args:2:1 Expected a comma before next function argument, got end of file