Add support for keywords and variadic arguments

6 files changed, 61 insertions, 16 deletions

diff --git a/.gitignore b/.gitignore
index f1cfca4..53f2c26 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
-/build/
+/build_gcc/
 /.direnv/
 /pit
 /*.a
diff --git a/include/lcq/pit/library.h b/include/lcq/pit/library.h
index ff325dc..6bca3a6 100644
--- a/include/lcq/pit/library.h
+++ b/include/lcq/pit/library.h
@@ -5,6 +5,7 @@
 
 void pit_install_library_essential(pit_runtime *rt);
 void pit_install_library_io(pit_runtime *rt);
+void pit_install_library_plist(pit_runtime *rt);
 void pit_install_library_bytestring(pit_runtime *rt);
 
 #endif
diff --git a/include/lcq/pit/runtime.h b/include/lcq/pit/runtime.h
index a8b6593..32bf198 100644
--- a/include/lcq/pit/runtime.h
+++ b/include/lcq/pit/runtime.h
@@ -60,7 +60,7 @@ typedef struct { /* "heavy" values, the targets of refs */
         struct { pit_value car, cdr; } cons;
         struct { pit_value *data; i64 len; } array;
         struct { u8 *data; i64 len; } bytes;
-        struct { pit_value env; pit_value args; pit_value body; } func;
+        struct { pit_value env; pit_value args; pit_value arg_rest_nm; pit_value body; } func;
         pit_nativefunc nativefunc;
         struct { pit_value tag; void *data; } nativedata;
     } in;
@@ -70,7 +70,7 @@ typedef struct {
     pit_value name; /* ref to bytestring */
     pit_value value; /* ref to cell */
     pit_value function; /* ref to cell */
-    bool is_macro, is_special_form;
+    bool is_macro, is_special_form, is_keyword;
 } pit_symtab_entry;
 
 /* "programs"; vectors of "instructions" for a very simple VM used by the evaluator */
@@ -206,7 +206,6 @@ pit_value pit_apply(pit_runtime *rt, pit_value f, pit_value args);
 /* working with native data */
 pit_value pit_nativedata_new(pit_runtime *rt, pit_value tag, void *d);
 
-
 /* evaluation! */
 pit_value pit_expand_macros(pit_runtime *rt, pit_value top);
 pit_value pit_eval(pit_runtime *rt, pit_value e);
diff --git a/src/library.c b/src/library.c
index 3175e27..9a40646 100644
--- a/src/library.c
+++ b/src/library.c
@@ -322,6 +322,22 @@ void pit_install_library_io(pit_runtime *rt) {
     pit_fset(rt, pit_intern_cstr(rt, "load!"), pit_nativefunc_new(rt, impl_load));
 }
 
+static pit_value impl_plist_get(pit_runtime *rt, pit_value args) {
+    pit_value k = pit_car(rt, args);
+    pit_value vs = pit_car(rt, pit_cdr(rt, args));
+    while (vs != PIT_NIL) {
+        if (pit_eq(k, pit_car(rt, vs))) {
+            return pit_car(rt, pit_cdr(rt, vs));
+        }
+        vs = pit_cdr(rt, vs);
+    }
+    return PIT_NIL;
+}
+void pit_install_library_plist(pit_runtime *rt) {
+    /* property lists / keyword arguments */
+    pit_fset(rt, pit_intern_cstr(rt, "plist/get"), pit_nativefunc_new(rt, impl_plist_get));
+}
+
 struct bytestring {
     i64 len, cap;
     u8 *data;
@@ -373,8 +389,10 @@ static pit_value impl_bs_delete(pit_runtime *rt, pit_value args) {
         return PIT_NIL;
     }
     struct bytestring *bs = h->in.nativedata.data;
-    if (bs->data) free(bs->data); bs->data = NULL;
-    free(bs); h->in.nativedata.data = NULL;
+    if (bs->data) free(bs->data);
+    bs->data = NULL;
+    free(bs);
+    h->in.nativedata.data = NULL;
     return PIT_T;
 }
 static pit_value impl_bs_grow(pit_runtime *rt, pit_value args) {
@@ -390,6 +408,7 @@ static pit_value impl_bs_grow(pit_runtime *rt, pit_value args) {
         }
         bs->len = sz;
     }
+    return v;
 }
 static pit_value impl_bs_spit(pit_runtime *rt, pit_value args) {
     pit_value path = pit_car(rt, args);
diff --git a/src/main.c b/src/main.c
index 2ea5ef8..bc697de 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,9 +5,14 @@
 #include <lcq/pit/lexer.h>
 #include <lcq/pit/parser.h>
 #include <lcq/pit/runtime.h>
+#include <lcq/pit/library.h>
 
 int main(int argc, char **argv) {
     pit_runtime *rt = pit_runtime_new();
+    pit_install_library_essential(rt);
+    pit_install_library_io(rt);
+    pit_install_library_plist(rt);
+    pit_install_library_bytestring(rt);
     if (argc < 2) { /* run repl */
         char buf[1024] = {0};
         i64 len = 0;
diff --git a/src/runtime.c b/src/runtime.c
index d0386ef..fcfe81a 100644
--- a/src/runtime.c
+++ b/src/runtime.c
@@ -87,9 +87,6 @@ pit_runtime *pit_runtime_new() {
     pit_set(ret, nil, PIT_NIL);
     pit_value truth = pit_intern_cstr(ret, "t");
     pit_set(ret, truth, truth);
-    pit_install_library_essential(ret);
-    pit_install_library_io(ret);
-    pit_install_library_bytestring(ret);
     pit_runtime_freeze(ret);
     return ret;
 }
@@ -489,6 +486,7 @@ pit_value pit_intern(pit_runtime *rt, u8 *nm, i64 len) {
     ent->function = PIT_NIL;
     ent->is_macro = false;
     ent->is_special_form = false;
+    ent->is_keyword = len >= 1 && nm[0] == ':';
     rt->symtab_len += 1;
     return pit_symbol_new(rt, idx);
 }
@@ -708,7 +706,7 @@ pit_value pit_free_vars(pit_runtime *rt, pit_value bound, pit_value body) {
     i64 expr_stack_reset = rt->expr_stack->top;
     pit_value ret = PIT_NIL;
     pit_values_push(rt, rt->expr_stack, body);
-    while (rt->expr_stack->top > 0) {
+    while (rt->expr_stack->top > expr_stack_reset) {
         pit_value cur = pit_values_pop(rt, rt->expr_stack);
         if (pit_is_cons(rt, cur)) {
             pit_value fsym = pit_car(rt, cur);
@@ -752,14 +750,26 @@ pit_value pit_lambda(pit_runtime *rt, pit_value args, pit_value body) {
     }
     h->hsort = PIT_VALUE_HEAVY_SORT_FUNC;
     pit_value arg_cells = PIT_NIL;
+    pit_value arg_rest_nm = PIT_NIL;
+    pit_value separator = pit_intern_cstr(rt, "&");
     while (args != PIT_NIL) {
         pit_value nm = pit_car(rt, args);
-        pit_value ent = pit_cons(rt, nm, pit_cell_new(rt, PIT_NIL));
-        arg_cells = pit_cons(rt, ent, arg_cells);
-        args = pit_cdr(rt, args);
+        if (pit_eq(nm, separator)) {
+            pit_value next_nm = pit_car(rt, pit_cdr(rt, args));
+            if (next_nm == PIT_NIL) { pit_error(rt, "invalid & in lambda list"); return PIT_NIL; }
+            arg_rest_nm = next_nm;
+            pit_value ent = pit_cons(rt, next_nm, pit_cell_new(rt, PIT_NIL));
+            arg_cells = pit_cons(rt, ent, arg_cells);
+            break;
+        } else {
+            pit_value ent = pit_cons(rt, nm, pit_cell_new(rt, PIT_NIL));
+            arg_cells = pit_cons(rt, ent, arg_cells);
+            args = pit_cdr(rt, args);
+        }
     }
     arg_cells = pit_reverse(rt, arg_cells);
     h->in.func.args = arg_cells;
+    h->in.func.arg_rest_nm = arg_rest_nm;
     h->in.func.env = env;
     h->in.func.body = expanded;
     return ret;
@@ -793,8 +803,14 @@ pit_value pit_apply(pit_runtime *rt, pit_value f, pit_value args) {
                 pit_value aform = pit_car(rt, anames);
                 pit_value nm = pit_car(rt, aform);
                 pit_value cell = pit_cdr(rt, aform);
-                pit_cell_set(rt, cell, pit_car(rt, args));
-                pit_bind(rt, nm, cell);
+                if (h->in.func.arg_rest_nm != PIT_NIL && pit_eq(nm, h->in.func.arg_rest_nm)) {
+                    pit_cell_set(rt, cell, args);
+                    pit_bind(rt, nm, cell);
+                    break;
+                } else {
+                    pit_cell_set(rt, cell, pit_car(rt, args));
+                    pit_bind(rt, nm, cell);
+                }
                 bound = pit_cons(rt, nm, bound);
                 args = pit_cdr(rt, args);
                 anames = pit_cdr(rt, anames);
@@ -998,7 +1014,12 @@ pit_value pit_eval(pit_runtime *rt, pit_value top) {
                 }
             }
         } else if (pit_is_symbol(rt, cur)) { /* unquoted symbols: variable lookup */
-            pit_runtime_eval_program_push_literal(rt, rt->program, pit_get(rt, cur));
+            pit_symtab_entry *ent = pit_symtab_lookup(rt, cur);
+            if (ent->is_keyword) {
+                pit_runtime_eval_program_push_literal(rt, rt->program, cur);
+            } else {
+                pit_runtime_eval_program_push_literal(rt, rt->program, pit_get(rt, cur));
+            }
         } else { /* other expressions evaluate to themselves! */
             pit_runtime_eval_program_push_literal(rt, rt->program, cur);
         }