make an Object interface, more stdlib func

CONTRIBUTING.md

@@ -11,7 +11,7 @@ In any case, the steps are the following, provided you already have a GitHub acc
 
 * File an issue (if it doesn't already exist)
 * Fork the repository
-* Create a working branch
+* Create a working branch from the *next* branch
 * Add test(s) to prove the bug, and write the fix. Make sure to use `gofmt` on your Go code
 * Run all the tests to make sure the fix did not break something else
 * Submit the pull request

runtime/builtin.go

@@ -6,7 +6,7 @@ import (
 
 type builtinMod struct {
 	ctx *Ctx
-	ob  *Object
+	ob  Object
 }
 
 func (b *builtinMod) ID() string {
@@ -85,8 +85,8 @@ func (b *builtinMod) _recover(args ...Val) (ret Val) {
 func (b *builtinMod) _len(args ...Val) Val {
 	ExpectAtLeastNArgs(1, args)
 	switch v := args[0].(type) {
-	case *Object:
-		return Number(len(v.m))
+	case Object:
+		return v.Len()
 	case null:
 		return Number(0)
 	default:

runtime/ctx.go

@@ -49,7 +49,7 @@ type Ctx struct {
 	// Modules management
 	loadingMods map[string]bool // Modules currently being loaded
 	loadedMods  map[string]Module
-	builtin     *Object
+	builtin     Object
 }
 
 // NewCtx returns a new execution context, using the provided module resolver
@@ -70,7 +70,7 @@ func NewCtx(resolver ModuleResolver, comp Compiler) *Ctx {
 	if v, err := b.Run(); err != nil {
 		panic("error loading angora builtin module: " + err.Error())
 	} else {
-		c.builtin = v.(*Object)
+		c.builtin = v.(Object)
 	}
 	return c
 }

runtime/funcvm.go

@@ -307,15 +307,15 @@ func (f *funcVM) run(args ...Val) Val {
 
 		case bytecode.OP_SFLD:
 			vr, k, vl := f.pop(), f.pop(), f.pop()
-			if ob, ok := vr.(*Object); ok {
+			if ob, ok := vr.(Object); ok {
 				ob.Set(k, vl)
 			} else {
 				panic(ErrValNotAnObject)
 			}
 
 		case bytecode.OP_GFLD:
 			vr, k := f.pop(), f.pop()
-			if ob, ok := vr.(*Object); ok {
+			if ob, ok := vr.(Object); ok {
 				f.push(ob.Get(k))
 			} else {
 				panic(ErrValNotAnObject)
@@ -328,7 +328,7 @@ func (f *funcVM) run(args ...Val) Val {
 			for j := ix; j > 0; j-- {
 				args[j-1] = f.pop()
 			}
-			if ob, ok := vr.(*Object); ok {
+			if ob, ok := vr.(Object); ok {
 				f.push(ob.callMethod(k, args...))
 			} else {
 				panic(ErrValNotAnObject)

runtime/object.go

@@ -24,20 +24,28 @@ var (
 	ErrInvalidNilKey    = errors.New("field key cannot be nil")
 )
 
-// An Object is a map of values, an associative array.
-type Object struct {
+type Object interface {
+	Val
+	Get(Val) Val
+	Set(Val, Val)
+	Len() Val
+	callMethod(Val, ...Val) Val
+}
+
+// An object is a map of values, an associative array.
+type object struct {
 	m map[Val]Val
 }
 
 // NewObject returns a new instance of an object.
-func NewObject() *Object {
-	return &Object{
+func NewObject() Object {
+	return &object{
 		make(map[Val]Val),
 	}
 }
 
 // dump pretty-prints the content of the object.
-func (o *Object) dump() string {
+func (o *object) dump() string {
 	buf := bytes.NewBuffer(nil)
 	for k, v := range o.m {
 		buf.WriteString(fmt.Sprintf(" %s: %s, ", k.dump(), v.dump()))
@@ -47,7 +55,7 @@ func (o *Object) dump() string {
 
 // Int returns the integer value of the object. Such behaviour can be defined
 // if a `__toInt` method is available on the object.
-func (o *Object) Int() int64 {
+func (o *object) Int() int64 {
 	if i, ok := o.m[String("__toInt")]; ok {
 		if f, ok := i.(Func); ok {
 			return f.Call(o).Int()
@@ -58,7 +66,7 @@ func (o *Object) Int() int64 {
 
 // Float returns the float value of the object. Such behaviour can be defined
 // if a `__toFloat` method is available on the object.
-func (o *Object) Float() float64 {
+func (o *object) Float() float64 {
 	if l, ok := o.m[String("__toFloat")]; ok {
 		if f, ok := l.(Func); ok {
 			return f.Call(o).Float()
@@ -69,7 +77,7 @@ func (o *Object) Float() float64 {
 
 // String returns the string value of the object. Such behaviour can be defined
 // if a `__toString` method is available on the object.
-func (o *Object) String() string {
+func (o *object) String() string {
 	if s, ok := o.m[String("__toString")]; ok {
 		if f, ok := s.(Func); ok {
 			return f.Call(o).String()
@@ -80,7 +88,7 @@ func (o *Object) String() string {
 
 // Bool returns the boolean value of the object. Such behaviour can be defined
 // if a `__toBool` method is available on the object. Otherwise it returns true.
-func (o *Object) Bool() bool {
+func (o *object) Bool() bool {
 	if b, ok := o.m[String("__toBool")]; ok {
 		if f, ok := b.(Func); ok {
 			return f.Call(o).Bool()
@@ -92,7 +100,7 @@ func (o *Object) Bool() bool {
 
 // Native returns the Go native value of the object. Such behaviour can be defined
 // if a `__toNative` method is available on the object.
-func (o *Object) Native() interface{} {
+func (o *object) Native() interface{} {
 	if n, ok := o.m[String("__toNative")]; ok {
 		if f, ok := n.(Func); ok {
 			return f.Call(o).Native()
@@ -104,7 +112,7 @@ func (o *Object) Native() interface{} {
 // Cmp compares the object to another value. Such behaviour can be defined
 // if a `__cmp` method is available on the object. Otherwise it returns 0 if
 // the compared value is the object, or -1 otherwise.
-func (o *Object) Cmp(v Val) int {
+func (o *object) Cmp(v Val) int {
 	// First check for a custom Cmp method
 	if c, ok := o.m[String("__cmp")]; ok {
 		if f, ok := c.(Func); ok {
@@ -118,7 +126,7 @@ func (o *Object) Cmp(v Val) int {
 	return -1
 }
 
-func (ø *Object) callBinaryMethod(nm String, err error, v Val) Val {
+func (ø *object) callBinaryMethod(nm String, err error, v Val) Val {
 	if m, ok := ø.m[nm]; ok {
 		if f, ok := m.(Func); ok {
 			return f.Call(ø, v)
@@ -129,37 +137,37 @@ func (ø *Object) callBinaryMethod(nm String, err error, v Val) Val {
 
 // Add performs addition. Such behaviour can be defined
 // if a `__add` method is available on the object.
-func (o *Object) Add(v Val) Val {
+func (o *object) Add(v Val) Val {
 	return o.callBinaryMethod(String("__add"), ErrInvalidOpAddOnObj, v)
 }
 
 // Sub performs subtraction. Such behaviour can be defined
 // if a `__sub` method is available on the object.
-func (o *Object) Sub(v Val) Val {
+func (o *object) Sub(v Val) Val {
 	return o.callBinaryMethod(String("__sub"), ErrInvalidOpSubOnObj, v)
 }
 
 // Mul performs multiplication. Such behaviour can be defined
 // if a `__mul` method is available on the object.
-func (o *Object) Mul(v Val) Val {
+func (o *object) Mul(v Val) Val {
 	return o.callBinaryMethod(String("__mul"), ErrInvalidOpMulOnObj, v)
 }
 
 // Div performs division. Such behaviour can be defined
 // if a `__div` method is available on the object.
-func (o *Object) Div(v Val) Val {
+func (o *object) Div(v Val) Val {
 	return o.callBinaryMethod(String("__div"), ErrInvalidOpDivOnObj, v)
 }
 
 // Mod computes the modulo. Such behaviour can be defined
 // if a `__mod` method is available on the object.
-func (o *Object) Mod(v Val) Val {
+func (o *object) Mod(v Val) Val {
 	return o.callBinaryMethod(String("__mod"), ErrInvalidOpModOnObj, v)
 }
 
 // Unm computes the unary minus. Such behaviour can be defined
 // if a `__unm` method is available on the object.
-func (o *Object) Unm() Val {
+func (o *object) Unm() Val {
 	if m, ok := o.m[String("__unm")]; ok {
 		if f, ok := m.(Func); ok {
 			return f.Call(o)
@@ -170,7 +178,7 @@ func (o *Object) Unm() Val {
 
 // Get the length of the object. The behaviour can be overridden
 // if a `__len` method is available on the object.
-func (o *Object) Len() Val {
+func (o *object) Len() Val {
 	if m, ok := o.m[String("__len")]; ok {
 		if f, ok := m.(Func); ok {
 			return f.Call(o)
@@ -181,7 +189,7 @@ func (o *Object) Len() Val {
 
 // Get returns the value of the field identified by key. It returns Nil
 // if the field does not exist.
-func (o *Object) Get(key Val) Val {
+func (o *object) Get(key Val) Val {
 	if v, ok := o.m[key]; ok {
 		return v
 	}
@@ -191,7 +199,7 @@ func (o *Object) Get(key Val) Val {
 // Set assigns the value v to the field identified by key. If the value
 // is Nil, set instead removes the key from the object. If the key is nil,
 // an error is raised.
-func (o *Object) Set(key Val, v Val) {
+func (o *object) Set(key Val, v Val) {
 	if v == Nil {
 		delete(o.m, key)
 	} else if key == Nil {
@@ -201,15 +209,10 @@ func (o *Object) Set(key Val, v Val) {
 	}
 }
 
-// Delete removes the field identified by the key from the object.
-func (o *Object) Delete(key Val) {
-	delete(o.m, key)
-}
-
 // callMethod calls the method identified by nm with the provided arguments.
 // It panics if the field does not hold a function. If the field does not
 // exist and a method named `__noSuchMethod` is defined, it is called instead.
-func (o *Object) callMethod(nm Val, args ...Val) Val {
+func (o *object) callMethod(nm Val, args ...Val) Val {
 	v, ok := o.m[nm]
 	if ok {
 		if f, ok := v.(Func); ok {

runtime/stdlib/conv.go

@@ -6,7 +6,7 @@ import (
 
 type ConvMod struct {
 	ctx *runtime.Ctx
-	ob  *runtime.Object
+	ob  runtime.Object
 }
 
 func (c *ConvMod) ID() string {
@@ -56,7 +56,7 @@ func (c *ConvMod) conv_Type(args ...runtime.Val) runtime.Val {
 		return runtime.String("bool")
 	case runtime.Func:
 		return runtime.String("func")
-	case *runtime.Object:
+	case runtime.Object:
 		return runtime.String("object")
 	default:
 		return runtime.String("nil")

runtime/stdlib/fmt.go

@@ -1,14 +1,15 @@
 package stdlib
 
 import (
+	"bufio"
 	"fmt"
 
 	"github.com/PuerkitoBio/agora/runtime"
 )
 
 type FmtMod struct {
 	ctx *runtime.Ctx
-	ob  *runtime.Object
+	ob  runtime.Object
 }
 
 func (f *FmtMod) ID() string {
@@ -22,6 +23,8 @@ func (f *FmtMod) Run(_ ...runtime.Val) (v runtime.Val, err error) {
 		f.ob = runtime.NewObject()
 		f.ob.Set(runtime.String("Print"), runtime.NewNativeFunc(f.ctx, "fmt.Print", f.fmt_Print))
 		f.ob.Set(runtime.String("Println"), runtime.NewNativeFunc(f.ctx, "fmt.Println", f.fmt_Println))
+		f.ob.Set(runtime.String("Scanln"), runtime.NewNativeFunc(f.ctx, "fmt.Scanln", f.fmt_Scanln))
+		f.ob.Set(runtime.String("Scanint"), runtime.NewNativeFunc(f.ctx, "fmt.Scanint", f.fmt_Scanint))
 	}
 	return f.ob, nil
 }
@@ -59,3 +62,27 @@ func (f *FmtMod) fmt_Println(args ...runtime.Val) runtime.Val {
 	}
 	return runtime.Number(n)
 }
+
+func (f *FmtMod) fmt_Scanln(args ...runtime.Val) runtime.Val {
+	var (
+		b, l []byte
+		e    error
+		pre  bool
+	)
+	r := bufio.NewReader(f.ctx.Stdin)
+	for l, pre, e = r.ReadLine(); pre && e == nil; l, pre, e = r.ReadLine() {
+		b = append(b, l...)
+	}
+	if e != nil {
+		panic(e)
+	}
+	return runtime.String(b)
+}
+
+func (f *FmtMod) fmt_Scanint(args ...runtime.Val) runtime.Val {
+	var i int
+	if _, e := fmt.Fscanf(f.ctx.Stdin, "%d", &i); e != nil {
+		panic(e)
+	}
+	return runtime.Number(i)
+}

runtime/stdlib/math.go

@@ -9,7 +9,7 @@ import (
 
 type MathMod struct {
 	ctx *runtime.Ctx
-	ob  *runtime.Object
+	ob  runtime.Object
 }
 
 func (m *MathMod) ID() string {