altos/lisp: Evaluate macros once, then smash them into place

[fw/altos] / src / lisp / ao_lisp_eval.c

diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index 5cc1b75a6838c6eae1f82541b541e23ba6bc1942..3af567964deab8a4f87d13a26d13425e3508e901 100644 (file)
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -298,7 +298,7 @@ ao_lisp_eval_formal(void)
                        break;
                case AO_LISP_FUNC_MACRO:
                        /* Evaluate the result once more */
-                       ao_lisp_stack->state = eval_sexpr;
+                       ao_lisp_stack->state = eval_macro;
                        if (!ao_lisp_stack_push())
                                return 0;
 
@@ -308,7 +308,6 @@ ao_lisp_eval_formal(void)
                        prev = ao_lisp_poly_stack(ao_lisp_stack->prev);
                        ao_lisp_stack->state = eval_sexpr;
                        ao_lisp_stack->sexprs = prev->sexprs;
-                       prev->sexprs = AO_LISP_NIL;
 
                        DBGI(".. start macro\n");
                        DBGI(".. sexprs       "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
@@ -555,6 +554,25 @@ ao_lisp_eval_while_test(void)
        return 1;
 }
 
+/*
+ * Replace the original sexpr with the macro expansion, then
+ * execute that
+ */
+static int
+ao_lisp_eval_macro(void)
+{
+       DBGI("macro: "); DBG_POLY(ao_lisp_v); DBG(" sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
+
+       if (ao_lisp_poly_type(ao_lisp_v) == AO_LISP_CONS) {
+               *ao_lisp_poly_cons(ao_lisp_stack->sexprs) = *ao_lisp_poly_cons(ao_lisp_v);
+               ao_lisp_v = ao_lisp_stack->sexprs;
+               DBGI("sexprs rewritten to: "); DBG_POLY(ao_lisp_v); DBG("\n");
+       }
+       ao_lisp_stack->sexprs = AO_LISP_NIL;
+       ao_lisp_stack->state = eval_sexpr;
+       return 1;
+}
+
 static int (*const evals[])(void) = {
        [eval_sexpr] = ao_lisp_eval_sexpr,
        [eval_val] = ao_lisp_eval_val,
@@ -565,6 +583,7 @@ static int (*const evals[])(void) = {
        [eval_progn] = ao_lisp_eval_progn,
        [eval_while] = ao_lisp_eval_while,
        [eval_while_test] = ao_lisp_eval_while_test,
+       [eval_macro] = ao_lisp_eval_macro,
 };
 
 /*