From fd5aad95dcec68419214ed46dc2b3d628f9e51ff Mon Sep 17 00:00:00 2001
From: Max Regan <mgregan2@gmail.com>
Date: Wed, 16 Nov 2022 21:38:01 -0500
Subject: [PATCH] Add iteration (dotimes, dolist, while)

---
 src/main.c    |  7 +++---
 src/special.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/special.h |  3 +++
 3 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/src/main.c b/src/main.c
index 127d6ec..dc0f4d4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -25,9 +25,6 @@ int main(int argc, const char **argv) {
     ucl_scope_put(scope, "and", ucl_special_create(ucl_special_and));
     ucl_scope_put(scope, "or", ucl_special_create(ucl_special_or));
 
-    // TODO:
-    //   - iteration
-
     ucl_scope_put(scope, "print", ucl_builtin_create(ucl_builtin_print));
     ucl_scope_put(scope, "printl", ucl_builtin_create(ucl_builtin_printl));
     // TODO:
@@ -65,6 +62,10 @@ int main(int argc, const char **argv) {
     ucl_scope_put(scope, "mapcar", ucl_builtin_create(ucl_builtin_mapcar));
     ucl_scope_put(scope, "equal", ucl_builtin_create(ucl_builtin_mapcar));
 
+    ucl_scope_put(scope, "dotimes", ucl_special_create(ucl_special_dotimes));
+    ucl_scope_put(scope, "dolist", ucl_special_create(ucl_special_dolist));
+    ucl_scope_put(scope, "while", ucl_special_create(ucl_special_while));
+
     // TODO:
     //   - reduce
 
diff --git a/src/special.c b/src/special.c
index 68cf6af..ce35aab 100644
--- a/src/special.c
+++ b/src/special.c
@@ -1,5 +1,6 @@
 #include "scope.h"
 #include "lisp.h"
+#include "uclisp.h"
 #include "utility.h"
 #include "internal.h"
 
@@ -84,6 +85,69 @@ struct ucl_object *ucl_special_lambda(struct ucl_scope *scope, struct ucl_object
     return args;
 }
 
+struct ucl_object *ucl_special_dotimes(struct ucl_scope *scope, struct ucl_object *args) {
+   // TODO: Check arguments
+    struct ucl_object *assignment = ucl_car(args);
+    struct ucl_object *body = ucl_cdr(args);
+
+    struct ucl_object *var = ucl_car(assignment);
+    struct ucl_object *times = ucl_evaluate(scope, ucl_list_nth(assignment, 1));
+
+    UCL_COND_OR_RET_ERROR(var->type == UCL_TYPE_SYMBOL, "'var' argument to dotimes must be an symbol");
+    UCL_COND_OR_RET_ERROR(times->type == UCL_TYPE_INT, "'times' argument to dotimes must be an int");
+
+    struct ucl_scope *let_scope = ucl_scope_create_child(scope);
+
+    for (int i = 0; i < times->integer; i++) {
+        ucl_scope_put(let_scope, var->symbol, ucl_int_create(i));
+        struct ucl_object *iterval = ucl_progn(let_scope, body);
+        UCL_RET_IF_ERROR(iterval);
+    }
+
+    return ucl_nil_create();
+}
+
+struct ucl_object *ucl_special_dolist(struct ucl_scope *scope, struct ucl_object *args) {
+   // TODO: Check arguments
+    struct ucl_object *assignment = ucl_car(args);
+    struct ucl_object *body = ucl_cdr(args);
+
+    struct ucl_object *var = ucl_car(assignment);
+    struct ucl_object *list = ucl_evaluate(scope, ucl_list_nth(assignment, 1));
+
+    UCL_COND_OR_RET_ERROR(var->type == UCL_TYPE_SYMBOL, "'var' argument to dolist must be an symbol");
+    UCL_COND_OR_RET_ERROR(list->type == UCL_TYPE_CELL, "'list' argument to dolist must be a list");
+
+    struct ucl_scope *let_scope = ucl_scope_create_child(scope);
+
+    FOREACH_LIST(list, iter, item) {
+        ucl_scope_put(let_scope, var->symbol, item);
+        struct ucl_object *iterval = ucl_progn(let_scope, body);
+        if (iterval->type == UCL_TYPE_ERROR) {
+            ucl_scope_delete(let_scope);
+        }
+        UCL_RET_IF_ERROR(iterval);
+    }
+
+    return ucl_nil_create();
+}
+
+struct ucl_object *ucl_special_while(struct ucl_scope *scope, struct ucl_object *args) {
+   // TODO: Check arguments
+    struct ucl_object *condition = ucl_car(args);
+    struct ucl_object *body = ucl_cdr(args);
+
+    while (1) {
+        struct ucl_object* cond_val = ucl_evaluate(scope, condition);
+        UCL_RET_IF_ERROR(cond_val);
+        if (!ucl_truthy_bool(cond_val)) {
+            return ucl_nil_create();
+        }
+
+        struct ucl_object *val = ucl_progn(scope, body);
+        UCL_RET_IF_ERROR(val);
+    }
+}
 
 struct ucl_object *ucl_special_setq(struct ucl_scope *scope, struct ucl_object *args) {
     // TODO: Check arguments
diff --git a/src/special.h b/src/special.h
index 7c43554..01e0bec 100644
--- a/src/special.h
+++ b/src/special.h
@@ -7,6 +7,9 @@ struct ucl_object *ucl_special_let(struct ucl_scope *scope, struct ucl_object *a
 struct ucl_object *ucl_special_if(struct ucl_scope *scope, struct ucl_object *args);
 struct ucl_object *ucl_special_defun(struct ucl_scope *scope, struct ucl_object *args);
 struct ucl_object *ucl_special_lambda(struct ucl_scope *scope, struct ucl_object *args);
+struct ucl_object *ucl_special_dotimes(struct ucl_scope *scope, struct ucl_object *args);
+struct ucl_object *ucl_special_dolist(struct ucl_scope *scope, struct ucl_object *args);
+struct ucl_object *ucl_special_while(struct ucl_scope *scope, struct ucl_object *args);
 struct ucl_object *ucl_special_setq(struct ucl_scope *scope, struct ucl_object *args);
 struct ucl_object *ucl_special_progn(struct ucl_scope *scope, struct ucl_object *args);
 struct ucl_object *ucl_special_quote(struct ucl_scope *scope, struct ucl_object *args);