Expand - Stub format_args! impl

2 files changed, 54 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index f34e5e01..8247f984 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ OBJ += ast/ast.o ast/crate.o ast/path.o ast/expr.o ast/pattern.o
 OBJ += ast/provided_module.o
 OBJ += parse/parseerror.o parse/lex.o
 OBJ += parse/root.o parse/paths.o parse/types.o parse/expr.o parse/pattern.o parse/macro_rules.o
-OBJ += expand/mod.o expand/macro_rules.o expand/cfg.o
+OBJ += expand/mod.o expand/macro_rules.o expand/cfg.o expand/format_args.o
 OBJ += dump_as_rust.o
 OBJ += convert/ast_iterate.o
 #OBJ += convert/decorators.o
diff --git a/src/expand/format_args.cpp b/src/expand/format_args.cpp
new file mode 100644
index 00000000..0c809601
--- /dev/null
+++ b/src/expand/format_args.cpp
@@ -0,0 +1,53 @@
+/*
+ */
+#include <synext.hpp>
+#include "../parse/common.hpp"
+#include "../parse/parseerror.hpp"
+#include "../parse/tokentree.hpp"
+#include "../parse/lex.hpp"
+
+class CFormatArgsExpander:
+    public ExpandProcMacro
+{
+    bool    expand_early() const override { return true; }
+    
+    ::std::unique_ptr<TokenStream> expand(Span sp, const ::std::string& ident, const TokenTree& tt, AST::Module& mod) override
+    {
+        Token   tok;
+        
+        auto lex = TTStream(tt);
+        if( ident != "" )
+            ERROR(sp, E0000, "format_args! doesn't take an ident");
+        
+        GET_CHECK_TOK(tok, lex, TOK_STRING);
+        auto format_string = mv$(tok.str());
+        
+        // TODO: Interpolated expression "tokens"
+        ::std::map< ::std::string, TokenTree>   named_args;
+        ::std::vector<TokenTree>    free_args;
+        
+        while( GET_TOK(tok, lex) == TOK_COMMA )
+        {
+            if( lex.lookahead(0) == TOK_IDENT && lex.lookahead(1) == TOK_EQUAL )
+            {
+                GET_CHECK_TOK(tok, lex, TOK_IDENT);
+                auto name = mv$(tok.str());
+                GET_CHECK_TOK(tok, lex, TOK_EQUAL);
+                auto expr_tt = Parse_TT_Expr(lex);
+                
+                named_args.insert( ::std::make_pair(mv$(name), mv$(expr_tt)) );
+            }
+            else
+            {
+                auto expr_tt = Parse_TT_Expr(lex);
+                free_args.push_back( mv$(expr_tt) );
+            }
+        }
+        
+        // TODO: Expand format_args!
+        return box$( TTStreamO(TokenTree(::std::vector<TokenTree>{TokenTree(TOK_PAREN_OPEN), TokenTree(TOK_PAREN_CLOSE)})) );
+    }
+};
+
+STATIC_MACRO("format_args", CFormatArgsExpander);
+