blob: 12835c4c0288db443db865a9335c9a57e2604f80 [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package eval
import (
"log"
"go/token"
"reflect"
)
/*
* Type bridging
*/
var (
evalTypes = make(map[reflect.Type]Type)
nativeTypes = make(map[Type]reflect.Type)
)
// TypeFromNative converts a regular Go type into a the corresponding
// interpreter Type.
func TypeFromNative(t reflect.Type) Type {
if et, ok := evalTypes[t]; ok {
return et
}
var nt *NamedType
if t.Name() != "" {
name := t.PkgPath() + "ยท" + t.Name()
nt = &NamedType{token.NoPos, name, nil, true, make(map[string]Method)}
evalTypes[t] = nt
}
var et Type
switch t := t.(type) {
case *reflect.BoolType:
et = BoolType
case *reflect.FloatType:
switch t.Kind() {
case reflect.Float32:
et = Float32Type
case reflect.Float64:
et = Float64Type
}
case *reflect.IntType:
switch t.Kind() {
case reflect.Int16:
et = Int16Type
case reflect.Int32:
et = Int32Type
case reflect.Int64:
et = Int64Type
case reflect.Int8:
et = Int8Type
case reflect.Int:
et = IntType
}
case *reflect.UintType:
switch t.Kind() {
case reflect.Uint16:
et = Uint16Type
case reflect.Uint32:
et = Uint32Type
case reflect.Uint64:
et = Uint64Type
case reflect.Uint8:
et = Uint8Type
case reflect.Uint:
et = UintType
case reflect.Uintptr:
et = UintptrType
}
case *reflect.StringType:
et = StringType
case *reflect.ArrayType:
et = NewArrayType(int64(t.Len()), TypeFromNative(t.Elem()))
case *reflect.ChanType:
log.Panicf("%T not implemented", t)
case *reflect.FuncType:
nin := t.NumIn()
// Variadic functions have DotDotDotType at the end
variadic := t.DotDotDot()
if variadic {
nin--
}
in := make([]Type, nin)
for i := range in {
in[i] = TypeFromNative(t.In(i))
}
out := make([]Type, t.NumOut())
for i := range out {
out[i] = TypeFromNative(t.Out(i))
}
et = NewFuncType(in, variadic, out)
case *reflect.InterfaceType:
log.Panicf("%T not implemented", t)
case *reflect.MapType:
log.Panicf("%T not implemented", t)
case *reflect.PtrType:
et = NewPtrType(TypeFromNative(t.Elem()))
case *reflect.SliceType:
et = NewSliceType(TypeFromNative(t.Elem()))
case *reflect.StructType:
n := t.NumField()
fields := make([]StructField, n)
for i := 0; i < n; i++ {
sf := t.Field(i)
// TODO(austin) What to do about private fields?
fields[i].Name = sf.Name
fields[i].Type = TypeFromNative(sf.Type)
fields[i].Anonymous = sf.Anonymous
}
et = NewStructType(fields)
case *reflect.UnsafePointerType:
log.Panicf("%T not implemented", t)
default:
log.Panicf("unexpected reflect.Type: %T", t)
}
if nt != nil {
if _, ok := et.(*NamedType); !ok {
nt.Complete(et)
et = nt
}
}
nativeTypes[et] = t
evalTypes[t] = et
return et
}
// TypeOfNative returns the interpreter Type of a regular Go value.
func TypeOfNative(v interface{}) Type { return TypeFromNative(reflect.Typeof(v)) }
/*
* Function bridging
*/
type nativeFunc struct {
fn func(*Thread, []Value, []Value)
in, out int
}
func (f *nativeFunc) NewFrame() *Frame {
vars := make([]Value, f.in+f.out)
return &Frame{nil, vars}
}
func (f *nativeFunc) Call(t *Thread) { f.fn(t, t.f.Vars[0:f.in], t.f.Vars[f.in:f.in+f.out]) }
// FuncFromNative creates an interpreter function from a native
// function that takes its in and out arguments as slices of
// interpreter Value's. While somewhat inconvenient, this avoids
// value marshalling.
func FuncFromNative(fn func(*Thread, []Value, []Value), t *FuncType) FuncValue {
return &funcV{&nativeFunc{fn, len(t.In), len(t.Out)}}
}
// FuncFromNativeTyped is like FuncFromNative, but constructs the
// function type from a function pointer using reflection. Typically,
// the type will be given as a nil pointer to a function with the
// desired signature.
func FuncFromNativeTyped(fn func(*Thread, []Value, []Value), t interface{}) (*FuncType, FuncValue) {
ft := TypeOfNative(t).(*FuncType)
return ft, FuncFromNative(fn, ft)
}