we can now quote with '

bin/pre.slime

@@ -5,12 +5,22 @@
     "Checks if the argument is nil."
     (= x nil)))
 
-(define append
+(define last
-  (lambda (obj sequence)
+  (lambda (seq)
-    (if (nil? sequence)
+    "Returns the last element of the given sequence."
-        (list obj)
+    (if (nil? seq)
-      (if (nil? (rest sequence))
+        seq
-          ))))
+      (if (not (= (type (rest seq)) :pair))
+          (first seq)
+        (last (rest seq))))))
+
+(define n-times
+  (lambda (times action)
+    (if (<= times 0)
+        nil
+      (prog
+       (eval action)
+       (n-times (- 1 times) action)))))
 
 (define range
   (lambda (:keys from :defaults-to 0 to)

src/parse.c

@@ -164,12 +164,27 @@ Ast_Node* parse_atom(char* text, int* index_in_text) {
 }
 
 Ast_Node* parse_expression(char* text, int* index_in_text) {
-    // okay we know the text under the index is '('
+    if (text[*index_in_text] == '\'') {
+        ++(*index_in_text);
+        Ast_Node* result;
+        if (text[*index_in_text] == '(' || text[*index_in_text] == '\'' ) {
+            try {
+                result = parse_expression(text, index_in_text);
+            }
+        } else {
+            try {
+                result = parse_atom(text, index_in_text);
+            }
+        }
+        return create_ast_node_pair(
+            create_ast_node_symbol("quote"),
+            create_ast_node_pair(result, create_ast_node_nil()));
+    }
     ++(*index_in_text);
 
     eat_whitespace(text, index_in_text);
 
-    // if there was actually nothing in the list return nil
+    // if there was actually nothing in the list, return nil
     if (text[(*index_in_text)] == ')') {
         ++(*index_in_text);
         return create_ast_node_nil();
@@ -182,7 +197,7 @@ Ast_Node* parse_expression(char* text, int* index_in_text) {
     Ast_Node* expression = head;
 
     while (true) {
-        if (text[(*index_in_text)] == '(') {
+        if (text[(*index_in_text)] == '(' || text[(*index_in_text)] == '\'' ) {
             head->value.pair->first = parse_expression(text, index_in_text);
         } else {
             head->value.pair->first = parse_atom(text, index_in_text);
@@ -226,7 +241,7 @@ Ast_Node* parse_single_expression(char* text) {
     int index_in_text = 0;
     Ast_Node* result;
     eat_until_code(text, &index_in_text);
-    if (text[(index_in_text)] == '(')
+    if (text[(index_in_text)] == '(' || text[(index_in_text)] == '\'' )
         result = parse_expression(text, &index_in_text);
     else
         result = parse_atom(text, &index_in_text);

todo.org

@@ -208,8 +208,8 @@ set to see if we are in an errornious state.
    CLOSED: [2018-09-18 Di 12:14]
 ** TODO >
 ** TODO <
-** TODO =
+** DONE =
-
+   CLOSED: [2018-10-21 So 00:25]
 ** DONE if
    CLOSED: [2018-09-18 Di 12:14]
 ** DONE and (short circuiting)
@@ -235,11 +235,16 @@ set to see if we are in an errornious state.
 ** DONE pair   (cons)
    CLOSED: [2018-10-08 Mo 20:28]
 
-** TODO load   (import)
+** DONE load   (import)
+   CLOSED: [2018-10-21 So 00:25]
 ** DONE define
    CLOSED: [2018-10-08 Mo 20:28]
-** TODO lambda
+** TODO mutateW
-** TODO progn
+** DONE lambda
+   CLOSED: [2018-10-21 So 00:25]
+** TODO macro
+** DONE prog
+   CLOSED: [2018-10-21 So 00:25]
 ** DONE eval
    CLOSED: [2018-10-08 Mo 20:28]
 
@@ -276,11 +281,3 @@ set to see if we are in an errornious state.
    CLOSED: [2018-10-08 Mo 21:30]
 
 ** TODO info
-
-* Types
- - Symbol
- - Number
- - String
- - pair (cons-cell)
- - lambda function lambda
- - built-in function