Added 2 tests and asthelpers.go

internal/zig/ast.go

@@ -27,14 +27,21 @@ type Decl interface {
 	isDecl()
 }
 
+// FnFlags is a bitfield for function declaration options.
+type FnFlags uint8
+
+const (
+	FnExport FnFlags = 1 << iota
+	FnExtern
+	FnInline
+	FnNoInline
+	FnThreadLocal
+)
+
 // FnDecl represents a function declaration.
 type FnDecl struct {
-	Export      bool
-	Extern      bool
+	Flags       FnFlags
 	ExternName  string // Optional string for extern
-	Inline      bool
-	NoInline    bool
-	ThreadLocal bool
 	Name        string // May be empty (anonymous)
 	Params      []*ParamDecl
 	ByteAlign   *Expr
@@ -47,13 +54,22 @@ type FnDecl struct {
 
 func (*FnDecl) isDecl() {}
 
-// GlobalVarDecl represents a global variable declaration.
+// GlobalVarFlags is a bitfield for global variable declaration options.
+type GlobalVarFlags uint8
+
+const (
+	GlobalVarConst GlobalVarFlags = 1 << iota
+	GlobalVarExport
+	GlobalVarExtern
+	GlobalVarThreadLocal
+)
+
+// GlobalVarDecl represents a top-level (global) variable or constant declaration.
+// These are only allowed at the container/module scope and use a restricted syntax:
+// no destructuring or multi-var declarations, just a single name and optional type/initializer.
 type GlobalVarDecl struct {
-	Export      bool
-	Extern      bool
+	Flags       GlobalVarFlags
 	ExternName  string // Optional string for extern
-	ThreadLocal bool
-	Const       bool
 	Name        string
 	Type        TypeExpr // Optional
 	ByteAlign   *Expr
@@ -95,6 +111,25 @@ type ParamDecl struct {
 	Type       TypeExpr // 'anytype' if empty
 }
 
+// ContainerDecl represents a struct, enum, union, or opaque declaration.
+type ContainerDecl struct {
+	Extern     bool
+	Packed     bool
+	Kind       string   // "struct", "enum", "union", "opaque"
+	TagType    TypeExpr // Optional (for enum/union)
+	Fields     []*ContainerMember
+	DocComment DocComment
+}
+
+func (*ContainerDecl) isDecl() {}
+
+// ErrorSetDecl represents an error set declaration.
+type ErrorSetDecl struct {
+	Names []string
+}
+
+func (*ErrorSetDecl) isDecl() {}
+
 // Block represents a block of statements.
 type Block struct {
 	Label string // Optional
@@ -113,7 +148,8 @@ type ExprStmt struct {
 
 func (*ExprStmt) isStmt() {}
 
-// VarDeclStmt represents a variable or const declaration at statement level, supporting destructuring and multi-var declarations.
+// VarDeclStmt represents a local variable or constant declaration statement inside a function or block.
+// These support destructuring and multi-var declarations, and are only valid at statement/block scope.
 type VarDeclStmt struct {
 	Const       bool
 	Pattern     VarPattern // Destructuring or multiple variable names
@@ -276,21 +312,6 @@ type AsmInputItem struct {
 	Expr       Expr
 }
 
-// ContainerDecl represents a struct, enum, union, or opaque declaration.
-type ContainerDecl struct {
-	Extern     bool
-	Packed     bool
-	Kind       string   // "struct", "enum", "union", "opaque"
-	TagType    TypeExpr // Optional (for enum/union)
-	Fields     []*ContainerMember
-	DocComment DocComment
-}
-
-// ErrorSetDecl represents an error set declaration.
-type ErrorSetDecl struct {
-	Names []string
-}
-
 // InitListExpr represents an initializer list.
 // Exactly one of Fields, Values, or Empty must be set (non-nil/non-empty or true).
 type InitListExpr struct {
@@ -381,6 +402,12 @@ type Expr interface{}
 // TypeExpr is any type expression.
 type TypeExpr interface{}
 
+// PrefixTypeExpr represents a type with a string prefix. Examples include optionals and pointers.
+type PrefixTypeExpr struct {
+	Op   string
+	Base TypeExpr
+}
+
 // DocComment represents a doc comment (/// or //! lines).
 // Newlines in the string automatically add more comments in the output.
 type DocComment string