add first-pass implementation of hs_parse_overloaded

2 files changed, 31 insertions, 1 deletions

diff --git a/README.md b/README.md
index 432100b..ad32264 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,9 @@ with helpful error messages.
 integer that will be filled with the stack index of the argument.
 
 Please note that, due to technical limitations, this function can 
-only parse up to 255 arguments.
+only parse up to 255 arguments. This function may mutate any 
+preexisting contents of the variables passed to contain the 
+arguments.
 
 ```c
 int some_lua_binding(lua_State *L)
@@ -132,6 +134,9 @@ actually used.
 If none of the argument lists match the provided arguments, this 
 function throws an error.
 
+This function may mutate preexisting data in the variables passed to 
+store arguments.
+
 ```c
 int overloaded_lua_binding(lua_State *L)
 {
diff --git a/src/hs_parse_args.c b/src/hs_parse_args.c
index 685561e..d6d3b3c 100644
--- a/src/hs_parse_args.c
+++ b/src/hs_parse_args.c
@@ -112,6 +112,16 @@ void hs_parse_args_(lua_State *L, int n_args, struct hs_arg *arguments)
    }
 }
 
+
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+static void hs_overloaded_error(lua_State *L, va_list args)
+{
+   lua_pushstring(L, "hs_overloaded failed");
+   lua_error(L);
+}
+
+
 int hs_parse_overloaded_(lua_State *L, ...)
 {
    va_list args, args_error;
@@ -119,6 +129,21 @@ int hs_parse_overloaded_(lua_State *L, ...)
    va_copy(args_error, args);
 
    int choice = 0;
+
+   while(true) {
+      int n_args = va_arg(args, int);
+      if (n_args == -1)
+	 break;
+      else {
+	 struct hs_arg *arguments = va_arg(args, struct hs_arg *);
+	 if (try_parse_args(L, n_args, arguments))
+	    return choice;
+      }
+      choice++;
+   }
+
+   hs_overloaded_error(L, args_error);
+   
    va_end(args);
    va_end(args_error);
 }