syntax errors with proper line and column

errors/errors.go

@@ -14,13 +14,13 @@ type Location struct {
 
 func Errorf(format string, a ...interface{}) *GraphQLError {
 	return &GraphQLError{
-		Message: fmt.Sprintf(format, a),
+		Message: fmt.Sprintf(format, a...),
 	}
 }
 
 func ErrorfWithLoc(line int, column int, format string, a ...interface{}) *GraphQLError {
 	return &GraphQLError{
-		Message: fmt.Sprintf(format, a),
+		Message: fmt.Sprintf(format, a...),
 		Locations: []*Location{{
 			Line:   line,
 			Column: column,

internal/lexer/lexer.go

@@ -4,9 +4,11 @@ import (
 	"fmt"
 	"strconv"
 	"text/scanner"
+
+	"github.com/neelance/graphql-go/errors"
 )
 
-type SyntaxError string
+type syntaxError string
 
 type Lexer struct {
 	sc   *scanner.Scanner
@@ -19,6 +21,21 @@ func New(sc *scanner.Scanner) *Lexer {
 	return l
 }
 
+func (l *Lexer) CatchSyntaxError(f func()) (errRes *errors.GraphQLError) {
+	defer func() {
+		if err := recover(); err != nil {
+			if err, ok := err.(syntaxError); ok {
+				errRes = errors.ErrorfWithLoc(l.sc.Line, l.sc.Column, "syntax error: %s", err)
+				return
+			}
+			panic(err)
+		}
+	}()
+
+	f()
+	return
+}
+
 func (l *Lexer) Peek() rune {
 	return l.next
 }
@@ -72,5 +89,5 @@ func (l *Lexer) ConsumeToken(expected rune) {
 }
 
 func (l *Lexer) SyntaxError(message string) {
-	panic(SyntaxError(fmt.Sprintf("%s:%d: syntax error: %s", l.sc.Filename, l.sc.Line, message)))
+	panic(syntaxError(message))
 }

internal/query/query.go

@@ -93,23 +93,17 @@ type Literal struct {
 func (Variable) isValue() {}
 func (Literal) isValue()  {}
 
-func Parse(queryString string) (res *Document, errRes *errors.GraphQLError) {
+func Parse(queryString string) (doc *Document, err *errors.GraphQLError) {
 	sc := &scanner.Scanner{
 		Mode: scanner.ScanIdents | scanner.ScanFloats | scanner.ScanStrings,
 	}
 	sc.Init(strings.NewReader(queryString))
 
-	defer func() {
-		if err := recover(); err != nil {
-			if err, ok := err.(lexer.SyntaxError); ok {
-				errRes = errors.Errorf("%s", string(err))
-				return
-			}
-			panic(err)
-		}
-	}()
-
-	return parseDocument(lexer.New(sc)), nil
+	l := lexer.New(sc)
+	err = l.CatchSyntaxError(func() {
+		doc = parseDocument(l)
+	})
+	return
 }
 
 func parseDocument(l *lexer.Lexer) *Document {

internal/schema/schema.go

@@ -80,23 +80,19 @@ type Parameter struct {
 	Default string
 }
 
-func Parse(schemaString string) (res *Schema, errRes *errors.GraphQLError) {
+func Parse(schemaString string) (s *Schema, err *errors.GraphQLError) {
 	sc := &scanner.Scanner{
 		Mode: scanner.ScanIdents | scanner.ScanFloats | scanner.ScanStrings,
 	}
 	sc.Init(strings.NewReader(schemaString))
 
-	defer func() {
-		if err := recover(); err != nil {
-			if err, ok := err.(lexer.SyntaxError); ok {
-				errRes = errors.Errorf("%s", string(err))
-				return
-			}
-			panic(err)
-		}
-	}()
-
-	s := parseSchema(lexer.New(sc))
+	l := lexer.New(sc)
+	err = l.CatchSyntaxError(func() {
+		s = parseSchema(l)
+	})
+	if err != nil {
+		return nil, err
+	}
 
 	for _, obj := range s.Objects {
 		if obj.Implements != "" {