v1.3.0-pre.2

README.md

@@ -24,7 +24,7 @@
 
 </div>
 
-Our vision is to **enable everyone to create production-level applications**.
+Our vision is to **enable everyone to become a builder of the digital world**.
 
 #### Easy to learn
 
@@ -46,13 +46,14 @@ For more details, see [Quick Start](doc/docs.md).
 
 ## Key Features of Go+
 
-* Approaching natural language expression and intuitive (see [Command Style Code](#command-style-code)).
-* Fully compatible with [Go](https://github.com/golang/go) and can mix Go/Go+ code in the same package (see [Go/Go+ Hybrid Programming](doc/docs.md#gogo-hybrid-programming)).
-* Integrating with the C ecosystem including Python and providing limitless possibilities (see [Support for C/C++ and Python](#support-for-cc-and-python)).
+* Approaching natural language expression and intuitive (see [How Go+ simplifies Go's expressions](#how-go-simplifies-gos-expressions)).
+* Smallest but Turing-complete syntax set in best practices (see [Go+ Specification for STEM Education](doc/spec-mini.md)).
+* Fully compatible with [Go](https://github.com/golang/go) and can mix Go/Go+ code in the same package (see [Go+ Full Specification](doc/spec.md) and [Go/Go+ Hybrid Programming](doc/docs.md#gogo-hybrid-programming)).
+* Integrating with the C ecosystem including Python and providing limitless possibilities based on [LLGo](https://github.com/goplus/llgo) (see [Support for C/C++ and Python](#support-for-cc-and-python)).
 * Does not support DSL (Domain-Specific Languages), but supports SDF (Specific Domain Friendliness) (see [Go+ Classfiles](#go-classfiles)).
 
 
-## Command Style Code
+## How Go+ simplifies Go's expressions
 
 Different from the function call style of most languages, Go+ recommends command style code:
 
@@ -68,6 +69,20 @@ echo "Hello world"
 
 For more discussion on coding style, see https://tutorial.goplus.org/hello-world.
 
+Code style is just the first step. We have made many efforts to make the code more intuitive and closer to natural language expression. These include:
+
+| Go code | Go+ code | Note |
+| ---- | ---- | ---- |
+| package main<br><br>import "fmt"<br><br>func main() {<br>&nbsp;&nbsp;&nbsp;&nbsp;fmt.Println("Hi")<br>} | import "fmt"<br><br>fmt.Println("Hi")<br> | Program structure: Go+ allows omitting `package main` and `func main` |
+| fmt.Println("Hi") | echo("Hi") | More builtin functions: It simplifies the expression of the most common tasks |
+| fmt.Println("Hi") | echo "Hi" | Command-line style code: It reduces the number of parentheses in the code as much as possible, making it closer to natural language |
+| a := []int{1, 2, 3} | a := [1, 2, 3] | List literals |
+| a := map[string]int{<br>&nbsp;&nbsp;&nbsp;&nbsp;"Monday": 1,<br>&nbsp;&nbsp;&nbsp;&nbsp;"Tuesday": 2,<br>} | a := {<br>&nbsp;&nbsp;&nbsp;&nbsp;"Monday": 1,<br>&nbsp;&nbsp;&nbsp;&nbsp;"Tuesday": 2,<br>} | Mapping literals |
+| OnStart(func() {<br>&nbsp;&nbsp;&nbsp;&nbsp;...<br>}) | onStart => {<br>&nbsp;&nbsp;&nbsp;&nbsp;...<br>} | Lambda expressions |
+| type Rect struct {<br>&nbsp;&nbsp;&nbsp;&nbsp;Width&nbsp; float64<br>&nbsp;&nbsp;&nbsp;&nbsp;Height float64<br>}<br><br>func (this *Rect) Area() float64 { <br>&nbsp;&nbsp;&nbsp;&nbsp;return this.Width * this.Height<br>} | var (<br>&nbsp;&nbsp;&nbsp;&nbsp;Width&nbsp; float64<br>&nbsp;&nbsp;&nbsp;&nbsp;Height float64<br>)<br><br>func Area() float64 { <br>&nbsp;&nbsp;&nbsp;&nbsp;return Width * Height<br>} | [Go+ Classfiles](doc/classfile.md): We can express OOP with global variables and functions. |
+
+For more details, see [Go+ Specification for STEM Education](doc/spec-mini.md).
+
 
 ## Support for C/C++ and Python
 
@@ -100,7 +115,7 @@ module YourModulePath
 
 go 1.21 // llgo 1.0
 
-require github.com/goplus/llgo v0.9.1
+require github.com/goplus/llgo v0.9.7
 ```
 
 Based on LLGo, Go+ can support importing libraries written in C/C++ and Python.

cl/compile_test.go

@@ -4122,3 +4122,132 @@ func _() {
 }
 `)
 }
+
+func TestSliceLitAssign(t *testing.T) {
+	gopClTest(t, `
+var n = 1
+var a []any = [10, 3.14, 200]
+n, a = 100, [10, 3.14, 200]
+echo a, n
+`, `package main
+
+import "fmt"
+
+var n = 1
+var a []interface{} = []interface{}{10, 3.14, 200}
+
+func main() {
+	n, a = 100, []interface{}{10, 3.14, 200}
+	fmt.Println(a, n)
+}
+`)
+}
+
+func TestSliceLitReturn(t *testing.T) {
+	gopClTest(t, `
+func anyslice() (int, []any) {
+	return 100, [10, 3.14, 200]
+}
+n, a := anyslice()
+echo n, a
+`, `package main
+
+import "fmt"
+
+func anyslice() (int, []interface{}) {
+	return 100, []interface{}{10, 3.14, 200}
+}
+func main() {
+	n, a := anyslice()
+	fmt.Println(n, a)
+}
+`)
+}
+
+func TestCompositeLitAssign(t *testing.T) {
+	gopClTest(t, `
+var a map[any]any = {10: "A", 3.14: "B", 200: "C"}
+var b map[any]string = {10: "A", 3.14: "B", 200: "C"}
+echo a
+echo b
+var n int
+n, a = 1, {10: "A", 3.14: "B", 200: "C"}
+echo a, n
+n, b = 1, {10: "A", 3.14: "B", 200: "C"}
+echo b, n
+`, `package main
+
+import "fmt"
+
+var a map[interface{}]interface{} = map[interface{}]interface{}{10: "A", 3.14: "B", 200: "C"}
+var b map[interface{}]string = map[interface{}]string{10: "A", 3.14: "B", 200: "C"}
+
+func main() {
+	fmt.Println(a)
+	fmt.Println(b)
+	var n int
+	n, a = 1, map[interface{}]interface{}{10: "A", 3.14: "B", 200: "C"}
+	fmt.Println(a, n)
+	n, b = 1, map[interface{}]string{10: "A", 3.14: "B", 200: "C"}
+	fmt.Println(b, n)
+}
+`)
+}
+
+func TestCompositeLitStruct(t *testing.T) {
+	gopClTest(t, `
+type T struct {
+	s  []any
+	m  map[any]any
+	fn func(int) int
+}
+
+echo &T{[10, 3.14, 200], {10: "A", 3.14: "B", 200: "C"}, (x => x)}
+echo &T{s: [10, 3.14, 200], m: {10: "A", 3.14: "B", 200: "C"}, fn: (x => x)}
+`, `package main
+
+import "fmt"
+
+type T struct {
+	s  []interface{}
+	m  map[interface{}]interface{}
+	fn func(int) int
+}
+
+func main() {
+	fmt.Println(&T{[]interface{}{10, 3.14, 200}, map[interface{}]interface{}{10: "A", 3.14: "B", 200: "C"}, func(x int) int {
+		return x
+	}})
+	fmt.Println(&T{s: []interface{}{10, 3.14, 200}, m: map[interface{}]interface{}{10: "A", 3.14: "B", 200: "C"}, fn: func(x int) int {
+		return x
+	}})
+}
+`)
+}
+
+func TestCompositeLitEx(t *testing.T) {
+	gopClTest(t, `
+var a [][]any = {[10, 3.14, 200], [100, 200]}
+var m map[any][]any = {10: [10, 3.14, 200]}
+var f map[any]func(int) int = {10: x => x}
+
+echo a
+echo m
+echo f
+`, `package main
+
+import "fmt"
+
+var a [][]interface{} = [][]interface{}{[]interface{}{10, 3.14, 200}, []interface{}{100, 200}}
+var m map[interface{}][]interface{} = map[interface{}][]interface{}{10: []interface{}{10, 3.14, 200}}
+var f map[interface{}]func(int) int = map[interface{}]func(int) int{10: func(x int) int {
+	return x
+}}
+
+func main() {
+	fmt.Println(a)
+	fmt.Println(m)
+	fmt.Println(f)
+}
+`)
+}

cl/error_msg_test.go

@@ -1071,3 +1071,30 @@ func (foo).++ = (
 )
 `)
 }
+
+func TestCompositeLitError(t *testing.T) {
+	codeErrorTest(t, `bar.gop:2:22: cannot use 3.14 (type untyped float) as type int in slice literal`, `
+var a [][]int = {[10,3.14,200],[100,200]}
+echo a
+`)
+	codeErrorTest(t, `bar.gop:2:17: cannot use lambda literal as type int in assignment`, `
+var a []int = {(x => x)}
+echo a
+`)
+	codeErrorTest(t, `bar.gop:2:35: cannot use x (type int) as type string in return argument`, `
+var a []func(int) string = {(x => x)}
+echo a
+`)
+	codeErrorTest(t, `bar.gop:2:27: cannot use lambda literal as type int in assignment to "A"`, `
+var a map[any]int = {"A": x => x}
+`)
+	codeErrorTest(t, `bar.gop:2:45: cannot use x (type int) as type string in return argument`, `
+var a map[any]func(int) string = {"A": x => x}
+`)
+	codeErrorTest(t, `bar.gop:2:24: cannot use lambda literal as type int in field value`, `
+var a = struct{v int}{(x => x)}
+`)
+	codeErrorTest(t, `bar.gop:2:27: cannot use lambda literal as type int in field value to v`, `
+var a = struct{v int}{v: (x => x)}
+`)
+}

cl/expr.go

@@ -853,8 +853,11 @@ retry:
 		typ = t.Underlying()
 		goto retry
 	}
-	src := ctx.LoadExpr(toNode)
-	return nil, ctx.newCodeErrorf(lambda.Pos(), "cannot use lambda literal as type %v in %v to %v", ftyp, flag, src)
+	var to string
+	if toNode != nil {
+		to = " to " + ctx.LoadExpr(toNode)
+	}
+	return nil, ctx.newCodeErrorf(lambda.Pos(), "cannot use lambda literal as type %v in %v%v", ftyp, flag, to)
 }
 
 func compileLambda(ctx *blockCtx, lambda ast.Expr, sig *types.Signature) {
@@ -1065,30 +1068,68 @@ func checkCompositeLitElts(elts []ast.Expr) (kind int) {
 	return compositeLitVal
 }
 
-func compileCompositeLitElts(ctx *blockCtx, elts []ast.Expr, kind int, expected *kvType) {
+func compileCompositeLitElts(ctx *blockCtx, elts []ast.Expr, kind int, expected *kvType) error {
 	for _, elt := range elts {
 		if kv, ok := elt.(*ast.KeyValueExpr); ok {
 			if key, ok := kv.Key.(*ast.CompositeLit); ok && key.Type == nil {
 				compileCompositeLit(ctx, key, expected.Key(), false)
 			} else {
 				compileExpr(ctx, kv.Key)
 			}
-			if val, ok := kv.Value.(*ast.CompositeLit); ok && val.Type == nil {
-				compileCompositeLit(ctx, val, expected.Elem(), false)
-			} else {
-				compileExpr(ctx, kv.Value)
+			err := compileCompositeLitElt(ctx, kv.Value, expected.Elem(), clLambaAssign, kv.Key)
+			if err != nil {
+				return err
 			}
 		} else {
 			if kind == compositeLitKeyVal {
 				ctx.cb.None()
 			}
-			if val, ok := elt.(*ast.CompositeLit); ok && val.Type == nil {
-				compileCompositeLit(ctx, val, expected.Elem(), false)
-			} else {
-				compileExpr(ctx, elt)
+			err := compileCompositeLitElt(ctx, elt, expected.Elem(), clLambaAssign, nil)
+			if err != nil {
+				return err
 			}
 		}
 	}
+	return nil
+}
+
+func compileCompositeLitElt(ctx *blockCtx, e ast.Expr, typ types.Type, flag clLambaFlag, toNode ast.Node) error {
+	switch v := unparen(e).(type) {
+	case *ast.LambdaExpr, *ast.LambdaExpr2:
+		sig, err := checkLambdaFuncType(ctx, v, typ, flag, toNode)
+		if err != nil {
+			return err
+		}
+		compileLambda(ctx, v, sig)
+	case *ast.SliceLit:
+		compileSliceLit(ctx, v, typ)
+	case *ast.CompositeLit:
+		compileCompositeLit(ctx, v, typ, false)
+	default:
+		compileExpr(ctx, v)
+	}
+	return nil
+}
+
+func unparen(x ast.Expr) ast.Expr {
+	if e, ok := x.(*ast.ParenExpr); ok {
+		return e.X
+	}
+	return x
+}
+
+func compileStructLit(ctx *blockCtx, elts []ast.Expr, t *types.Struct, typ types.Type, src *ast.CompositeLit) error {
+	for idx, elt := range elts {
+		if idx >= t.NumFields() {
+			return ctx.newCodeErrorf(elt.Pos(), "too many values in %v{...}", typ)
+		}
+		err := compileCompositeLitElt(ctx, elt, t.Field(idx).Type(), clLambaField, nil)
+		if err != nil {
+			return err
+		}
+	}
+	ctx.cb.StructLit(typ, len(elts), false, src)
+	return nil
 }
 
 func compileStructLitInKeyVal(ctx *blockCtx, elts []ast.Expr, t *types.Struct, typ types.Type, src *ast.CompositeLit) error {
@@ -1105,15 +1146,9 @@ func compileStructLitInKeyVal(ctx *blockCtx, elts []ast.Expr, t *types.Struct, t
 		if rec := ctx.recorder(); rec != nil {
 			rec.Use(name, t.Field(idx))
 		}
-		switch expr := kv.Value.(type) {
-		case *ast.LambdaExpr, *ast.LambdaExpr2:
-			sig, err := checkLambdaFuncType(ctx, expr, t.Field(idx).Type(), clLambaField, kv.Key)
-			if err != nil {
-				return err
-			}
-			compileLambda(ctx, expr, sig)
-		default:
-			compileExpr(ctx, kv.Value)
+		err := compileCompositeLitElt(ctx, kv.Value, t.Field(idx).Type(), clLambaField, kv.Key)
+		if err != nil {
+			return err
 		}
 	}
 	ctx.cb.StructLit(typ, len(elts)<<1, true, src)
@@ -1194,12 +1229,21 @@ func compileCompositeLitEx(ctx *blockCtx, v *ast.CompositeLit, expected types.Ty
 			typ, underlying = expected, tu
 		}
 	}
-	if t, ok := underlying.(*types.Struct); ok && kind == compositeLitKeyVal {
-		if err := compileStructLitInKeyVal(ctx, v.Elts, t, typ, v); err != nil {
+	if t, ok := underlying.(*types.Struct); ok {
+		var err error
+		if kind == compositeLitKeyVal {
+			err = compileStructLitInKeyVal(ctx, v.Elts, t, typ, v)
+		} else {
+			err = compileStructLit(ctx, v.Elts, t, typ, v)
+		}
+		if err != nil {
 			return err
 		}
 	} else {
-		compileCompositeLitElts(ctx, v.Elts, kind, &kvType{underlying: underlying})
+		err := compileCompositeLitElts(ctx, v.Elts, kind, &kvType{underlying: underlying})
+		if err != nil {
+			return err
+		}
 		n := len(v.Elts)
 		if isMap(underlying) {
 			if kind == compositeLitVal && n > 0 {
@@ -1214,8 +1258,6 @@ func compileCompositeLitEx(ctx *blockCtx, v *ast.CompositeLit, expected types.Ty
 				ctx.cb.SliceLitEx(typ, n<<kind, kind == compositeLitKeyVal, v)
 			case *types.Array:
 				ctx.cb.ArrayLitEx(typ, n<<kind, kind == compositeLitKeyVal, v)
-			case *types.Struct:
-				ctx.cb.StructLit(typ, n, false, v) // key-val mode handled by compileStructLitInKeyVal
 			default:
 				return ctx.newCodeErrorf(v.Pos(), "invalid composite literal type %v", typ)
 			}