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|
package types
import (
"errors"
"fmt"
"reflect"
"strings"
)
// Errors/Exceptions
type MalError struct {
Obj MalType
}
func (e MalError) Error() string {
return fmt.Sprintf("%#v", e.Obj)
}
// General types
type MalType interface {
}
type EnvType interface {
Find(key Symbol) EnvType
Set(key Symbol, value MalType) MalType
Get(key Symbol) (MalType, error)
}
// Scalars
func Nil_Q(obj MalType) bool {
if obj == nil {
return true
} else {
return false
}
}
func True_Q(obj MalType) bool {
switch tobj := obj.(type) {
case bool:
return tobj == true
default:
return false
}
}
func False_Q(obj MalType) bool {
switch tobj := obj.(type) {
case bool:
return tobj == false
default:
return false
}
}
// Symbols
type Symbol struct {
Val string
}
func Symbol_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "Symbol"
}
// Keywords
func NewKeyword(s string) (MalType, error) {
return "\u029e" + s, nil
}
func Keyword_Q(obj MalType) bool {
if obj == nil {
return false
}
switch s := obj.(type) {
case string:
return strings.HasPrefix(s, "\u029e")
default:
return false
}
}
// Strings
func String_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "string"
}
// Functions
type Func struct {
Fn func([]MalType) (MalType, error)
Meta MalType
}
func Func_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "Func"
}
type MalFunc struct {
Eval func(MalType, EnvType) (MalType, error)
Exp MalType
Env EnvType
Params MalType
IsMacro bool
GenEnv func(EnvType, MalType, MalType) (EnvType, error)
Meta MalType
}
func MalFunc_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "MalFunc"
}
func (f MalFunc) SetMacro() MalType {
f.IsMacro = true
return f
}
func (f MalFunc) GetMacro() bool {
return f.IsMacro
}
// Take either a MalFunc or regular function and apply it to the
// arguments
func Apply(f_mt MalType, a []MalType) (MalType, error) {
switch f := f_mt.(type) {
case MalFunc:
env, e := f.GenEnv(f.Env, f.Params, List{a, nil})
if e != nil {
return nil, e
}
return f.Eval(f.Exp, env)
case Func:
return f.Fn(a)
case func([]MalType) (MalType, error):
return f(a)
default:
return nil, errors.New("Invalid function to Apply")
}
}
// Lists
type List struct {
Val []MalType
Meta MalType
}
func NewList(a ...MalType) MalType {
return List{a, nil}
}
func List_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "List"
}
// Vectors
type Vector struct {
Val []MalType
Meta MalType
}
func Vector_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "Vector"
}
func GetSlice(seq MalType) ([]MalType, error) {
switch obj := seq.(type) {
case List:
return obj.Val, nil
case Vector:
return obj.Val, nil
default:
return nil, errors.New("GetSlice called on non-sequence")
}
}
// Hash Maps
type HashMap struct {
Val map[string]MalType
Meta MalType
}
func NewHashMap(seq MalType) (MalType, error) {
lst, e := GetSlice(seq)
if e != nil {
return nil, e
}
if len(lst)%2 == 1 {
return nil, errors.New("Odd number of arguments to NewHashMap")
}
m := map[string]MalType{}
for i := 0; i < len(lst); i += 2 {
str, ok := lst[i].(string)
if !ok {
return nil, errors.New("expected hash-map key string")
}
m[str] = lst[i+1]
}
return HashMap{m, nil}, nil
}
func HashMap_Q(obj MalType) bool {
if obj == nil {
return false
}
return reflect.TypeOf(obj).Name() == "HashMap"
}
// Atoms
type Atom struct {
Val MalType
Meta MalType
}
func (a *Atom) Set(val MalType) MalType {
a.Val = val
return a
}
func Atom_Q(obj MalType) bool {
switch obj.(type) {
case *Atom:
return true
default:
return false
}
}
// General functions
func _obj_type(obj MalType) string {
if obj == nil {
return "nil"
}
return reflect.TypeOf(obj).Name()
}
func Sequential_Q(seq MalType) bool {
if seq == nil {
return false
}
return (reflect.TypeOf(seq).Name() == "List") ||
(reflect.TypeOf(seq).Name() == "Vector")
}
func Equal_Q(a MalType, b MalType) bool {
ota := reflect.TypeOf(a)
otb := reflect.TypeOf(b)
if !((ota == otb) || (Sequential_Q(a) && Sequential_Q(b))) {
return false
}
//av := reflect.ValueOf(a); bv := reflect.ValueOf(b)
//fmt.Printf("here2: %#v\n", reflect.TypeOf(a).Name())
//switch reflect.TypeOf(a).Name() {
switch a.(type) {
case Symbol:
return a.(Symbol).Val == b.(Symbol).Val
case List:
as, _ := GetSlice(a)
bs, _ := GetSlice(b)
if len(as) != len(bs) {
return false
}
for i := 0; i < len(as); i += 1 {
if !Equal_Q(as[i], bs[i]) {
return false
}
}
return true
case Vector:
as, _ := GetSlice(a)
bs, _ := GetSlice(b)
if len(as) != len(bs) {
return false
}
for i := 0; i < len(as); i += 1 {
if !Equal_Q(as[i], bs[i]) {
return false
}
}
return true
case HashMap:
return false
default:
return a == b
}
}
|
