Expand format_args! - Parse and (partially) emit

1 files changed, 75 insertions, 0 deletions

diff --git a/src/include/synext_decorator.hpp b/src/include/synext_decorator.hpp
new file mode 100644
index 00000000..5ae1af53
--- /dev/null
+++ b/src/include/synext_decorator.hpp
@@ -0,0 +1,75 @@
+/*
+ */
+#pragma once
+#ifndef _SYNEXT_DECORATOR_HPP_
+#define _SYNEXT_DECORATOR_HPP_
+
+#include <string>
+#include <memory>
+#include <span.hpp>
+#include "../ast/item.hpp"
+
+class TypeRef;
+namespace AST {
+    class Crate;
+    class MetaItem;
+    class Path;
+
+    struct StructItem;
+    struct TupleItem;
+    struct EnumVariant;
+    
+    class Module;
+    class Item;
+    
+    class Expr;
+    class ExprNode;
+    struct ExprNode_Match_Arm;
+    
+    class MacroInvocation;
+    
+    class ImplDef;
+}
+
+enum class AttrStage
+{
+    EarlyPre,
+    EarlyPost,
+    LatePre,
+    LatePost,
+};
+
+class ExpandDecorator
+{
+    void unexpected(const Span& sp, const AST::MetaItem& mi, const char* loc_str) const;
+public:
+    virtual AttrStage   stage() const = 0;
+    
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate) const { unexpected(sp, mi, "crate"); }
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, AST::MacroInvocation& mac) const { unexpected(sp, mi, "macro invocation"); }
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, const AST::Path& path, AST::Module& mod, AST::Item&i) const { unexpected(sp, mi, "item"); }
+    // NOTE: To delete, set the type to `_`
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, const AST::Module& mod, AST::ImplDef& impl) const { unexpected(sp, mi, "impl"); }
+    // NOTE: To delete, clear the name
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, ::AST::StructItem& si) const { unexpected(sp, mi, "struct item"); }
+    // NOTE: To delete, make the type invalid
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, ::AST::TupleItem& si) const { unexpected(sp, mi, "tuple item"); }
+    // NOTE: To delete, clear the name
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, ::AST::EnumVariant& ev) const { unexpected(sp, mi, "enum variant"); }
+    
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, ::std::unique_ptr<AST::ExprNode>& expr) const { unexpected(sp, mi, "expression"); }
+    // NOTE: To delete, clear the patterns vector
+    virtual void    handle(const Span& sp, const AST::MetaItem& mi, AST::Crate& crate, ::AST::ExprNode_Match_Arm& expr) const { unexpected(sp, mi, "match arm"); }
+};
+
+#define STATIC_DECORATOR(ident, _handler_class) \
+    struct register_##_handler_class##_c {\
+        register_##_handler_class##_c() {\
+            Register_Synext_Decorator( ident, ::std::unique_ptr<ExpandDecorator>(new _handler_class()) ); \
+        } \
+    } s_register_##_handler_class;
+
+extern void Register_Synext_Decorator(::std::string name, ::std::unique_ptr<ExpandDecorator> handler);
+
+#endif
+