package otto
import (
"errors"
"fmt"
"github.com/robertkrimen/otto/file"
)
type _exception struct {
value interface{}
}
func newException(value interface{}) *_exception {
return &_exception{
value: value,
}
}
func (self *_exception) eject() interface{} {
value := self.value
self.value = nil // Prevent Go from holding on to the value, whatever it is
return value
}
type _error struct {
name string
message string
trace []_frame
offset int
}
func (err _error) format() string {
if len(err.name) == 0 {
return err.message
}
if len(err.message) == 0 {
return err.name
}
return fmt.Sprintf("%s: %s", err.name, err.message)
}
func (err _error) formatWithStack() string {
str := err.format() + "\n"
for _, frame := range err.trace {
str += " at " + frame.location() + "\n"
}
return str
}
type _frame struct {
native bool
nativeFile string
nativeLine int
file *file.File
offset int
callee string
}
var (
nativeFrame = _frame{}
)
type _at int
func (fr _frame) location() string {
str := "<unknown>"
switch {
case fr.native:
str = "<native code>"
if fr.nativeFile != "" && fr.nativeLine != 0 {
str = fmt.Sprintf("%s:%d", fr.nativeFile, fr.nativeLine)
}
case fr.file != nil:
if p := fr.file.Position(file.Idx(fr.offset)); p != nil {
path, line, column := p.Filename, p.Line, p.Column
if path == "" {
path = "<anonymous>"
}
str = fmt.Sprintf("%s:%d:%d", path, line, column)
}
}
if fr.callee != "" {
str = fmt.Sprintf("%s (%s)", fr.callee, str)
}
return str
}
// An Error represents a runtime error, e.g. a TypeError, a ReferenceError, etc.
type Error struct {
_error
}
// Error returns a description of the error
//
// TypeError: 'def' is not a function
//
func (err Error) Error() string {
return err.format()
}
// String returns a description of the error and a trace of where the
// error occurred.
//
// TypeError: 'def' is not a function
// at xyz (<anonymous>:3:9)
// at <anonymous>:7:1/
//
func (err Error) String() string {
return err.formatWithStack()
}
func (err _error) describe(format string, in ...interface{}) string {
return fmt.Sprintf(format, in...)
}
func (self _error) messageValue() Value {
if self.message == "" {
return Value{}
}
return toValue_string(self.message)
}
func (rt *_runtime) typeErrorResult(throw bool) bool {
if throw {
panic(rt.panicTypeError())
}
return false
}
func newError(rt *_runtime, name string, stackFramesToPop int, in ...interface{}) _error {
err := _error{
name: name,
offset: -1,
}
description := ""
length := len(in)
if rt != nil && rt.scope != nil {
scope := rt.scope
for i := 0; i < stackFramesToPop; i++ {
if scope.outer != nil {
scope = scope.outer
}
}
frame := scope.frame
if length > 0 {
if at, ok := in[length-1].(_at); ok {
in = in[0 : length-1]
if scope != nil {
frame.offset = int(at)
}
length--
}
if length > 0 {
description, in = in[0].(string), in[1:]
}
}
limit := rt.traceLimit
err.trace = append(err.trace, frame)
if scope != nil {
for scope = scope.outer; scope != nil; scope = scope.outer {
if limit--; limit == 0 {
break
}
if scope.frame.offset >= 0 {
err.trace = append(err.trace, scope.frame)
}
}
}
} else {
if length > 0 {
description, in = in[0].(string), in[1:]
}
}
err.message = err.describe(description, in...)
return err
}
func (rt *_runtime) panicTypeError(argumentList ...interface{}) *_exception {
return &_exception{
value: newError(rt, "TypeError", 0, argumentList...),
}
}
func (rt *_runtime) panicReferenceError(argumentList ...interface{}) *_exception {
return &_exception{
value: newError(rt, "ReferenceError", 0, argumentList...),
}
}
func (rt *_runtime) panicURIError(argumentList ...interface{}) *_exception {
return &_exception{
value: newError(rt, "URIError", 0, argumentList...),
}
}
func (rt *_runtime) panicSyntaxError(argumentList ...interface{}) *_exception {
return &_exception{
value: newError(rt, "SyntaxError", 0, argumentList...),
}
}
func (rt *_runtime) panicRangeError(argumentList ...interface{}) *_exception {
return &_exception{
value: newError(rt, "RangeError", 0, argumentList...),
}
}
func catchPanic(function func()) (err error) {
defer func() {
if caught := recover(); caught != nil {
if exception, ok := caught.(*_exception); ok {
caught = exception.eject()
}
switch caught := caught.(type) {
case *Error:
err = caught
return
case _error:
err = &Error{caught}
return
case Value:
if vl := caught._object(); vl != nil {
switch vl := vl.value.(type) {
case _error:
err = &Error{vl}
return
}
}
err = errors.New(caught.string())
return
}
panic(caught)
}
}()
function()
return nil
}
