Add GoVarStmt, reduce GoRawStmt escape hatches

Add GoVarStmt type for in-body variable declarations. Convert 16
GoRawStmt instances to structured nodes: var declarations to GoVarStmt,
simple assignments to GoAssignStmt, defer to GoDeferStmt, comment to
GoComment. GoRawStmt drops from 64 to 48.

Author: rubiojr

compiler/codegen_build.go

@@ -260,9 +260,9 @@ func (g *codeGen) buildIf(i *ast.IfStmt) ([]GoStmt, error) {
 		if !g.isDeclared(name) {
 			varType := g.varType(name)
 			if varType.IsTyped() {
-				preDecls = append(preDecls, GoRawStmt{Code: fmt.Sprintf("var %s %s", name, varType.GoType())})
+				preDecls = append(preDecls, GoVarStmt{Name: name, Type: varType.GoType()})
 			} else {
-				preDecls = append(preDecls, GoRawStmt{Code: fmt.Sprintf("var %s interface{}", name)})
+				preDecls = append(preDecls, GoVarStmt{Name: name, Type: "interface{}"})
 			}
 			g.declareVar(name)
 		}
@@ -508,7 +508,7 @@ func (g *codeGen) buildFunc(f *ast.FuncDef) (GoFuncDecl, error) {
 
 	// Recursion depth guard
 	body = append(body, GoExprStmt{Expr: GoRawExpr{Code: fmt.Sprintf("rugo_check_depth(%q)", f.Name)}})
-	body = append(body, GoRawStmt{Code: "defer func() { rugo_call_depth-- }()"})
+	body = append(body, GoDeferStmt{Body: []GoStmt{GoRawStmt{Code: "rugo_call_depth--"}}})
 
 	if hasDefaults {
 		// Arity range check
@@ -525,13 +525,13 @@ func (g *codeGen) buildFunc(f *ast.FuncDef) (GoFuncDecl, error) {
 		for i, p := range f.Params {
 			g.declareVar(p.Name)
 			if p.Default == nil {
-				body = append(body, GoRawStmt{Code: fmt.Sprintf("var %s interface{} = _args[%d]", p.Name, i)})
+				body = append(body, GoVarStmt{Name: p.Name, Type: "interface{}", Value: GoRawExpr{Code: fmt.Sprintf("_args[%d]", i)}})
 			} else {
 				defaultExpr, err := g.exprString(p.Default)
 				if err != nil {
 					return GoFuncDecl{}, err
 				}
-				body = append(body, GoRawStmt{Code: fmt.Sprintf("var %s interface{}", p.Name)})
+				body = append(body, GoVarStmt{Name: p.Name, Type: "interface{}"})
 				body = append(body, GoRawStmt{Code: fmt.Sprintf("if len(_args) > %d { %s = _args[%d] } else { %s = %s }", i, p.Name, i, p.Name, defaultExpr)})
 			}
 			body = append(body, GoExprStmt{Expr: GoRawExpr{Code: fmt.Sprintf("_ = %s", p.Name)}})

compiler/codegen_expr.go

@@ -718,7 +718,7 @@ func (g *codeGen) loweredSpawnExpr(e *ast.LoweredSpawnExpr) (string, error) {
 					}},
 					GoRawStmt{Code: "close(t.done)"},
 				}},
-				GoRawStmt{Code: "// spawn body"},
+				GoComment{Text: "spawn body"},
 			}},
 		},
 		Result: GoRawExpr{Code: "interface{}(t)"},
@@ -789,10 +789,10 @@ func (g *codeGen) fnExpr(e *ast.FnExpr) (string, error) {
 			if derr != nil {
 				return "", derr
 			}
-			preamble = append(preamble, GoRawStmt{Code: fmt.Sprintf("var %s interface{}", p.Name)})
+			preamble = append(preamble, GoVarStmt{Name: p.Name, Type: "interface{}"})
 			preamble = append(preamble, GoRawStmt{Code: fmt.Sprintf("if len(_args) > %d { %s = _args[%d] } else { %s = %s }", i, p.Name, i, p.Name, defaultExpr)})
 		} else {
-			preamble = append(preamble, GoRawStmt{Code: fmt.Sprintf("var %s interface{}", p.Name)})
+			preamble = append(preamble, GoVarStmt{Name: p.Name, Type: "interface{}"})
 			preamble = append(preamble, GoRawStmt{Code: fmt.Sprintf("if len(_args) > %d { %s = _args[%d] }", i, p.Name, i)})
 		}
 		preamble = append(preamble, GoExprStmt{Expr: GoRawExpr{Code: fmt.Sprintf("_ = %s", p.Name)}})

compiler/codegen_func.go

@@ -22,23 +22,23 @@ func (g *codeGen) buildTestHarness(tests []*ast.TestDef, topStmts []ast.Statemen
 					GoIfStmt{
 						Cond: GoRawExpr{Code: "reason, ok := r.(rugoTestSkip); ok"},
 						Body: []GoStmt{
-							GoRawStmt{Code: "skipped = true"},
-							GoRawStmt{Code: "skipReason = string(reason)"},
+							GoAssignStmt{Target: "skipped", Op: "=", Value: GoRawExpr{Code: "true"}},
+							GoAssignStmt{Target: "skipReason", Op: "=", Value: GoRawExpr{Code: "string(reason)"}},
 							GoReturnStmt{},
 						},
 					},
-					GoRawStmt{Code: `failColor := "\033[31m"`},
-					GoRawStmt{Code: `failReset := "\033[0m"`},
+					GoAssignStmt{Target: "failColor", Op: ":=", Value: GoRawExpr{Code: `"\033[31m"`}},
+					GoAssignStmt{Target: "failReset", Op: ":=", Value: GoRawExpr{Code: `"\033[0m"`}},
 					GoIfStmt{
 						Cond: GoRawExpr{Code: `os.Getenv("NO_COLOR") != ""`},
 						Body: []GoStmt{
-							GoRawStmt{Code: `failColor = ""`},
-							GoRawStmt{Code: `failReset = ""`},
+							GoAssignStmt{Target: "failColor", Op: "=", Value: GoRawExpr{Code: `""`}},
+							GoAssignStmt{Target: "failReset", Op: "=", Value: GoRawExpr{Code: `""`}},
 						},
 					},
-					GoRawStmt{Code: `failReason = fmt.Sprintf("%v", r)`},
+					GoAssignStmt{Target: "failReason", Op: "=", Value: GoRawExpr{Code: `fmt.Sprintf("%v", r)`}},
 					GoRawStmt{Code: `fmt.Fprintf(os.Stderr, "  %sFAIL%s: %v\n", failColor, failReset, r)`},
-					GoRawStmt{Code: "passed = false"},
+					GoAssignStmt{Target: "passed", Op: "=", Value: GoRawExpr{Code: "false"}},
 				},
 			},
 		}}
@@ -56,7 +56,7 @@ func (g *codeGen) buildTestHarness(tests []*ast.TestDef, topStmts []ast.Statemen
 		g.popScope()
 
 		body = append(body, bodyStmts...)
-		body = append(body, GoRawStmt{Code: "passed = true"})
+		body = append(body, GoAssignStmt{Target: "passed", Op: "=", Value: GoRawExpr{Code: "true"}})
 		body = append(body, GoReturnStmt{})
 
 		decls = append(decls, GoFuncDecl{

compiler/goast.go

@@ -99,6 +99,15 @@ type GoReturnStmt struct {
 
 func (GoReturnStmt) goStmt() {}
 
+// GoVarStmt represents: var name type [= value]
+type GoVarStmt struct {
+	Name  string
+	Type  string
+	Value GoExpr // nil for uninitialized
+}
+
+func (GoVarStmt) goStmt() {}
+
 // GoIfStmt represents: if cond { body } [else if ...] [else { body }]
 type GoIfStmt struct {
 	Cond   GoExpr

compiler/goprint.go

@@ -123,6 +123,12 @@ func (p *goPrinter) printStmt(s GoStmt) {
 		} else {
 			p.line("return")
 		}
+	case GoVarStmt:
+		if st.Value != nil {
+			p.line("var %s %s = %s", st.Name, st.Type, p.exprStr(st.Value))
+		} else {
+			p.line("var %s %s", st.Name, st.Type)
+		}
 	case GoIfStmt:
 		p.printIf(st)
 	case GoForStmt: