pit: Fix evaluator

3 files changed, 30 insertions, 3 deletions

diff --git a/pit/include/lcq/pit/runtime.h b/pit/include/lcq/pit/runtime.h
index 70e65ca..feeb267 100644
--- a/pit/include/lcq/pit/runtime.h
+++ b/pit/include/lcq/pit/runtime.h
@@ -39,23 +39,47 @@ typedef struct {
 } pit_callstack_entry;
 PIT_DECLARE_VEC(pit_callstack_entry)
 
+/* entries on a stack used when compiling expressions */
+typedef struct {
+    enum {
+        PIT_COMPILATION_ENTRY_VALUE,
+        PIT_COMPILATION_ENTRY_DROP,
+        PIT_COMPILATION_ENTRY_BEGIN_CODE,
+        PIT_COMPILATION_ENTRY_END_CODE,
+    } sort;
+    union {
+        pit_value value;
+        /* void end_code; */
+    } in;
+} pit_compilation_entry;
+PIT_DECLARE_VEC(pit_compilation_entry)
+void pit_compilation_push_value(struct pit_runtime *rt, pit_vec(pit_compilation_entry) *s, pit_value x);
+void pit_compilation_push_drop(struct pit_runtime *rt, pit_vec(pit_compilation_entry) *s);
+void pit_compilation_push_begin_code(struct pit_runtime *rt, pit_vec(pit_compilation_entry) *s);
+void pit_compilation_push_end_code(struct pit_runtime *rt, pit_vec(pit_compilation_entry) *s);
+
 /* entries on a stack used when traversing trees of values */
 typedef struct {
     enum {
         PIT_TRAVERSAL_ENTRY_VALUE,
         PIT_TRAVERSAL_ENTRY_DUMP_STRING,
         PIT_TRAVERSAL_ENTRY_APPLICATION,
+        PIT_TRAVERSAL_ENTRY_BEGIN_CODE,
+        PIT_TRAVERSAL_ENTRY_END_CODE,
     } sort;
     union {
         pit_value value;
         char *dump_string;
         struct { i64 arity; pit_annotation *annotation; } application; 
+        /* void end_code; */
     } in;
 } pit_traversal_entry;
 PIT_DECLARE_VEC(pit_traversal_entry)
 void pit_traversal_push_value(struct pit_runtime *rt, pit_vec(pit_traversal_entry) *s, pit_value x);
 void pit_traversal_push_dump_string(struct pit_runtime *rt, pit_vec(pit_traversal_entry) *s, char *m);
 void pit_traversal_push_application(struct pit_runtime *rt, pit_vec(pit_traversal_entry) *s, i64 arity, pit_annotation *annotation);
+void pit_traversal_push_begin_code(struct pit_runtime *rt, pit_vec(pit_traversal_entry) *s);
+void pit_traversal_push_end_code(struct pit_runtime *rt, pit_vec(pit_traversal_entry) *s);
 
 typedef struct pit_runtime {
     /* interpreter state */
@@ -67,9 +91,10 @@ typedef struct pit_runtime {
     pit_hashtable(pit_ref, pit_annotation) *annotations_backbuffer;
     pit_vec(pit_symtab_entry) *symtab; /* all symbols */
     /* temporary/"scratch" memory */
-    pit_vec(pit_value) *saved_bindings; /* stack used to save old values of bindings to be restored ("shallow binding") */
+    pit_vec(pit_value) *saved_bindings; /* stack used to save old values of bindings ("shallow binding") */
     pit_vec(pit_value) *expr_stack; /* stack of subexpressions to evaluate during evaluation */
     pit_vec(pit_value) *result_stack; /* stack of intermediate values during evaluation */
+    pit_vec(pit_compilation_entry) *compilation_stack; /* stack of subexpressions to compile */
     pit_vec(pit_traversal_entry) *traversal; /* intermediate stack used during tree traversal */
     pit_vec(pit_callstack_entry) *callstack; /* stack of enclosing function calls */
     /* bookkeeping */
@@ -78,6 +103,8 @@ typedef struct pit_runtime {
     pit_value error; /* error value - if this is non-nil, an error has occured! only tracks the first error */
     i64 source_line, source_column; /* for error reporting only; line and column of token start */
     i64 error_line, error_column; /* line and column of token start at time of error */
+    pit_value msg_out_of_memory; /* a pre-allocated "out of memory" error message */
+    /* we make sure to have this ready, since we can't allocate space for it if we run out! */
 } pit_runtime;
 pit_runtime *pit_runtime_new(u8 *buf, i64 len);
 
diff --git a/pit/include/lcq/pit/runtime/macroexpand.h b/pit/include/lcq/pit/runtime/macroexpand.h
index bc1f756..db56849 100644
--- a/pit/include/lcq/pit/runtime/macroexpand.h
+++ b/pit/include/lcq/pit/runtime/macroexpand.h
@@ -3,6 +3,7 @@
 
 #include <lcq/pit/runtime.h>
 
-pit_value pit_macroexpand(pit_runtime *rt, pit_value top);
+pit_value pit_macroexpand_1(pit_runtime *rt, pit_value f);
+pit_value pit_macroexpand(pit_runtime *rt, pit_value f);
 
 #endif
diff --git a/pit/include/lcq/pit/runtime/symtab.h b/pit/include/lcq/pit/runtime/symtab.h
index ac60523..e385884 100644
--- a/pit/include/lcq/pit/runtime/symtab.h
+++ b/pit/include/lcq/pit/runtime/symtab.h
@@ -20,7 +20,6 @@ void pit_symtab_symbol_mark_macro(pit_runtime *rt, pit_value sym);
 void pit_symtab_mset(pit_runtime *rt, pit_value sym, pit_value v);
 bool pit_symtab_is_symbol_special_form(pit_runtime *rt, pit_value sym);
 void pit_symtab_symbol_mark_special_form(pit_runtime *rt, pit_value sym);
-void pit_symtab_sfset(pit_runtime *rt, pit_value sym, pit_value v);
 void pit_symtab_bind(pit_runtime *rt, pit_value sym, pit_value v);
 pit_value pit_symtab_unbind(pit_runtime *rt, pit_value sym);