From 14814ecbf53760654aab34e0613abf347a54113f Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Thu, 14 Oct 2021 18:06:54 +0200
Subject: Add fun sugar for function variable declaration

---
 src/bootstrap/environment.c |  8 ++++----
 src/bootstrap/main.c        |  1 +
 src/bootstrap/objects.c     |  4 ++--
 src/bootstrap/primitives.c  | 43 +++++++++++++++++++++++++++++++++++++++----
 4 files changed, 46 insertions(+), 10 deletions(-)

(limited to 'src')

diff --git a/src/bootstrap/environment.c b/src/bootstrap/environment.c
index e111753..78f31fb 100644
--- a/src/bootstrap/environment.c
+++ b/src/bootstrap/environment.c
@@ -106,15 +106,15 @@ env_extend(Environment *parent, Environment *extra) {
     for (size_t i = 0; i < extra->size; i++) {
         EnvEntry entry = extra->buf[i];
         Environment *tmp = env;
-        ssize_t idx = -1;
+        bool found = false;
         while (tmp != NULL) {
-            idx = env_index_current(tmp, entry.symbol);
-            if (idx != -1) {
+            if (env_index_current(tmp, entry.symbol) != -1) {
+                found = true;
                 break;
             }
             tmp = tmp->parent;
         }
-        if (idx == -1) {
+        if (!found) {
             env_add_symbol(env, obj_duplicate(entry.symbol), obj_duplicate(entry.value));
         }
     }
diff --git a/src/bootstrap/main.c b/src/bootstrap/main.c
index 7591834..5191fd0 100755
--- a/src/bootstrap/main.c
+++ b/src/bootstrap/main.c
@@ -76,6 +76,7 @@ init(void) {
     MAKE_ENV_PROC(global_env, "def", proc_define);
     MAKE_ENV_PROC(global_env, "set!", proc_set);
     MAKE_ENV_PROC(global_env, "lambda", proc_lambda);
+    MAKE_ENV_PROC(global_env, "fun", proc_fun);
 
     // Runtime procedures.
     MAKE_ENV_PROC(global_env, "supress-errors", proc_supress_errors);
diff --git a/src/bootstrap/objects.c b/src/bootstrap/objects.c
index b3aa3de..b03a616 100644
--- a/src/bootstrap/objects.c
+++ b/src/bootstrap/objects.c
@@ -41,7 +41,7 @@ typedef struct Object {
 
         // OBJ_TYPE_LAMBDA
         struct {
-            struct Object *args;
+            struct Object *params;
             struct Object *body;
             struct Environment *env;
         };
@@ -186,7 +186,7 @@ free_objects(Object *root) {
             free(root);
         } break;
         case OBJ_TYPE_LAMBDA: {
-            free_objects(root->args);
+            free_objects(root->params);
             free_objects(root->body);
             // TODO: free_env(root->env);
             free(root);
diff --git a/src/bootstrap/primitives.c b/src/bootstrap/primitives.c
index 4ef56d5..4c3e4c6 100644
--- a/src/bootstrap/primitives.c
+++ b/src/bootstrap/primitives.c
@@ -54,7 +54,7 @@ eval_lambda:
             if (lambda->type == OBJ_TYPE_LAMBDA) {
                 Object *fun = lambda;
                 Object *args = root->cdr;
-                Object *params = fun->args;
+                Object *params = fun->params;
                 env = env_extend(fun->env, env);
                 while (params != obj_nil) {
                     if (args == obj_nil) {
@@ -742,8 +742,8 @@ proc_lambda(Environment *env, Object *obj) {
         });
         return obj_err;
     }
-    Object *args = obj->car;
-    if (args != obj_nil && args->type != OBJ_TYPE_PAIR) {
+    Object *params = obj->car;
+    if (params != obj_nil && params->type != OBJ_TYPE_PAIR) {
         error_push((Error){
             .type = ERR_TYPE_RUNTIME,
             .value = ERR_WRONG_ARG_TYPE,
@@ -752,12 +752,47 @@ proc_lambda(Environment *env, Object *obj) {
     }
     Object *body = obj->cdr;
     Object *fun = alloc_object(OBJ_TYPE_LAMBDA);
-    fun->args = obj_duplicate(args);
+    fun->params = obj_duplicate(params);
     fun->body = obj_duplicate(body);
     fun->env = env;
     return fun;
 }
 
+Object *
+proc_fun(Environment *env, Object *obj) {
+    if (obj == obj_nil || obj->cdr == obj_nil || obj->cdr->cdr == obj_nil) {
+        error_push((Error){
+            .type = ERR_TYPE_RUNTIME,
+            .value = ERR_NOT_ENOUGH_ARGS,
+        });
+        return obj_err;
+    }
+
+    Object *name = obj->car;
+    if (name->type != OBJ_TYPE_SYMBOL) {
+        error_push((Error){
+            .type = ERR_TYPE_RUNTIME,
+            .value = ERR_WRONG_ARG_TYPE,
+        });
+        return obj_err;
+    }
+
+    Object *params = obj->cdr->car;
+    if (params != obj_nil && params->type != OBJ_TYPE_PAIR) {
+        error_push((Error){
+            .type = ERR_TYPE_RUNTIME,
+            .value = ERR_WRONG_ARG_TYPE,
+        });
+        return obj_err;
+    }
+    Object *body = obj->cdr->cdr;
+    Object *fun = alloc_object(OBJ_TYPE_LAMBDA);
+    fun->params = obj_duplicate(params);
+    fun->body = obj_duplicate(body);
+    fun->env = env;
+    env_add_or_update_current(env, name, fun);
+    return obj_nil;
+}
 
 //
 // Evaluation.
-- 
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