Add lambda special form

src/main.c

@@ -16,6 +16,7 @@ int main(int argc, const char **argv) {
     ucl_state_put(state, "let", ucl_special_create(ucl_special_let));
     ucl_state_put(state, "if", ucl_special_create(ucl_special_if));
     ucl_state_put(state, "defun", ucl_special_create(ucl_special_defun));
+    ucl_state_put(state, "lambda", ucl_special_create(ucl_special_lambda));
     ucl_state_put(state, "setq", ucl_special_create(ucl_special_setq));
     ucl_state_put(state, "progn", ucl_special_create(ucl_special_progn));
 
@@ -23,7 +24,6 @@ int main(int argc, const char **argv) {
     //   - progn
     //   - quote
     //   - iteration
-    //   - lambda
 
     ucl_state_put(state, "print", ucl_builtin_create(ucl_builtin_print));
     ucl_state_put(state, "list", ucl_builtin_create(ucl_builtin_list));
@@ -55,6 +55,7 @@ int main(int argc, const char **argv) {
     //   - car
     //   - cdr
     //   - nth
+    //   - booleans (e.g. not)
 
     if (argc < 2) {
         while (1) {

src/special.c

@@ -71,12 +71,24 @@ struct ucl_object *ucl_special_defun(struct ucl_state *state, struct ucl_object
 
 }
 
+struct ucl_object *ucl_special_lambda(struct ucl_state *state, struct ucl_object *args) {
+   // TODO: Check arguments
+    struct ucl_object *fun_args = ucl_list_nth(args, 0);
+    if (fun_args->type != UCL_TYPE_CELL) {
+        // TODO: Check that the list contains only symbols
+        return ucl_error_create("First argument to lambda must be a list of symbols");
+    }
+
+    return args;
+}
+
+
 struct ucl_object *ucl_special_setq(struct ucl_state *state, struct ucl_object *args) {
     // TODO: Check arguments
     struct ucl_object *sym = ucl_car(args);
     struct ucl_state *root_state = ucl_state_get_root(state);
     if (sym->type != UCL_TYPE_SYMBOL) {
-        return ucl_error_create("First argument to defun must be a symbol");
+        return ucl_error_create("First argument to setq must be a symbol");
     }
 
     struct ucl_object *value = ucl_evaluate(state, ucl_list_nth(args, 1));

src/special.h

@@ -6,6 +6,7 @@
 struct ucl_object *ucl_special_let(struct ucl_state *state, struct ucl_object *args);
 struct ucl_object *ucl_special_if(struct ucl_state *state, struct ucl_object *args);
 struct ucl_object *ucl_special_defun(struct ucl_state *state, struct ucl_object *args);
+struct ucl_object *ucl_special_lambda(struct ucl_state *state, struct ucl_object *args);
 struct ucl_object *ucl_special_setq(struct ucl_state *state, struct ucl_object *args);
 struct ucl_object *ucl_special_progn(struct ucl_state *state, struct ucl_object *args);