impl lots of arithmetic operations and if

builtins.c

@@ -1,27 +1,39 @@
 #include "lisp.h"
 
-Node *lisp_function_addition(Nodes *args, Scopes *scopes) {
-    UNUSED(scopes);
-
-    if (args->count != 2) {
-        printf("'+' expects two arguments!\n");
-        return NULL;
+#define func_arithmetic_ex(name, operator, operator_name)                      \
+    Node *name(Nodes *args, Scopes *scopes) {                                  \
+        UNUSED(scopes);                                                        \
+        if (args->count != 2) {                                                \
+            puts("'" operator_name "' expects two arguments!\n");              \
+            return NULL;                                                       \
+        }                                                                      \
+        if (args->items[0].kind != NODE_KIND_NUMBER ||                         \
+            args->items[1].kind != NODE_KIND_NUMBER) {                         \
+            puts("'" operator_name                                             \
+                 "' only works on numbers, you specified something "           \
+                 "else!\n");                                                   \
+            return NULL;                                                       \
+        }                                                                      \
+        Node *node = malloc(sizeof(Node));                                     \
+        node->kind = NODE_KIND_NUMBER;                                         \
+        long long a = args->items[0].as_number;                                \
+        long long b = args->items[1].as_number;                                \
+        node->as_number = a operator b;                                        \
+        return node;                                                           \
     }
+#define func_arithmetic(name, operator)                                        \
+    func_arithmetic_ex(name, operator, #operator)
 
-    if (args->items[0].kind != NODE_KIND_NUMBER ||
-        args->items[1].kind != NODE_KIND_NUMBER) {
-        printf("'+' can only add numbers, you specified something else!\n");
-        return NULL;
-    }
-
-    Node *node = malloc(sizeof(Node));
-    node->kind = NODE_KIND_NUMBER;
-
-    intptr_t a = args->items[0].as_number;
-    intptr_t b = args->items[1].as_number;
-    node->as_number = a + b;
-    return node;
-}
+func_arithmetic(lisp_function_add, +);
+func_arithmetic(lisp_function_sub, -);
+func_arithmetic(lisp_function_div, /);
+func_arithmetic(lisp_function_mul, *);
+func_arithmetic(lisp_function_mod, %);
+func_arithmetic_ex(lisp_function_eq, ==, "=");
+func_arithmetic(lisp_function_lt, <);
+func_arithmetic(lisp_function_gt, >);
+func_arithmetic(lisp_function_lt_eq, <=);
+func_arithmetic(lisp_function_gt_eq, >=);
 
 Node *lisp_function_println(Nodes *args, Scopes *scopes) {
     if (args->count != 1) {
@@ -111,3 +123,21 @@ Node *lisp_function_isnull(Nodes *args, Scopes *scopes) {
     node->as_number = args->items[0].as_list->count == 0 ? 1 : 0;
     return node;
 }
+
+Node *lisp_function_builtins(Nodes *args, Scopes *scopes) {
+    if (args->count != 0) {
+        printf("'builtins' expects no arguments!\n");
+        return NULL;
+    }
+
+    Node *node = malloc(sizeof(Node));
+    node->kind = NODE_KIND_LIST;
+
+    Scope global_scope = nob_da_first(scopes);
+    Nodes *nodes = malloc(sizeof(Node));
+    nob_da_foreach(ScopeObject, scope_object, &global_scope) {
+        nob_da_append(nodes, scope_object->node);
+    }
+    node->as_list = nodes;
+    return node;
+}

lisp.c

@@ -25,14 +25,36 @@ static void scope_add_function(Scope *scope, const char *name,
     nob_da_append(scope, obj);
 }
 
+static bool node_is_true(Node node) {
+    switch (node.kind) {
+    case NODE_KIND_NUMBER:
+        return node.as_number != 0;
+    case NODE_KIND_LIST:
+        return node.as_list->count > 0;
+    default:
+        return true;
+    }
+}
+
 void build_scopes(Scopes *scopes) {
     // clang-format off
-    scope_add_function(&globalScope, "+", lisp_function_addition);
+    scope_add_function(&globalScope, "+", lisp_function_add);
+    scope_add_function(&globalScope, "-", lisp_function_sub);
+    scope_add_function(&globalScope, "/", lisp_function_div);
+    scope_add_function(&globalScope, "*", lisp_function_mul);
+    scope_add_function(&globalScope, "%", lisp_function_mod);
+    scope_add_function(&globalScope, "=", lisp_function_eq);
+    scope_add_function(&globalScope, "<", lisp_function_lt);
+    scope_add_function(&globalScope, ">", lisp_function_gt);
+    scope_add_function(&globalScope, "<=", lisp_function_lt_eq);
+    scope_add_function(&globalScope, ">=", lisp_function_gt_eq);
+
     scope_add_function(&globalScope, "println", lisp_function_println);
     scope_add_function(&globalScope, "list", lisp_function_list);
     scope_add_function(&globalScope, "append", lisp_function_append);
     scope_add_function(&globalScope, "length", lisp_function_length);
     scope_add_function(&globalScope, "null?", lisp_function_isnull);
+    scope_add_function(&globalScope, "builtins", lisp_function_builtins);
     // clang-format on
 
     nob_da_append(scopes, globalScope);
@@ -216,13 +238,25 @@ Node *eval(Node *node, Scopes *scopes) {
             return node;
 
         Node *head = &children->items[0];
-        Node *func_node = eval(head, scopes);
+        if (head->kind != NODE_KIND_SYMBOL)
+            return node;
 
         Nodes *args = malloc(sizeof(Nodes));
         for (size_t i = 1; i < children->count; i++) {
             nob_da_append(args, *eval(&children->items[i], scopes));
         }
 
+        if (nob_sv_eq(head->as_symbol,
+                      (Nob_String_View){.count = 2, .data = "if"})) {
+            if (args->count != 3) {
+                printf("'if' expects three arguments!\n");
+                return NULL;
+            }
+            Node *condition = eval(&args->items[0], scopes);
+            return node_is_true(*condition) ? eval(&args->items[1], scopes)
+                                            : eval(&args->items[2], scopes);
+        } else {
+            Node *func_node = eval(head, scopes);
             if (func_node->kind == NODE_KIND_FUNCTION) {
                 return func_node->as_function.apply(args, scopes);
             }
@@ -232,6 +266,7 @@ Node *eval(Node *node, Scopes *scopes) {
             printf("'\n");
             return NULL;
         }
+    }
     default:
         UNREACHABLE("");
     }

lisp.h

@@ -80,11 +80,23 @@ Node *parse(Tokens *tokens);
 Node *eval(Node *node, Scopes *scopes);
 
 // builtins
-Node *lisp_function_addition(Nodes *args, Scopes *scopes);
+Node *lisp_function_add(Nodes *args, Scopes *scopes);
+Node *lisp_function_sub(Nodes *args, Scopes *scopes);
+Node *lisp_function_div(Nodes *args, Scopes *scopes);
+Node *lisp_function_mul(Nodes *args, Scopes *scopes);
+Node *lisp_function_mod(Nodes *args, Scopes *scopes);
+
+Node *lisp_function_eq(Nodes *args, Scopes *scopes);
+Node *lisp_function_lt(Nodes *args, Scopes *scopes);
+Node *lisp_function_gt(Nodes *args, Scopes *scopes);
+Node *lisp_function_lt_eq(Nodes *args, Scopes *scopes);
+Node *lisp_function_gt_eq(Nodes *args, Scopes *scopes);
+
 Node *lisp_function_println(Nodes *args, Scopes *scopes);
 Node *lisp_function_list(Nodes *args, Scopes *scopes);
 Node *lisp_function_append(Nodes *args, Scopes *scopes);
 Node *lisp_function_length(Nodes *args, Scopes *scopes);
 Node *lisp_function_isnull(Nodes *args, Scopes *scopes);
+Node *lisp_function_builtins(Nodes *args, Scopes *scopes);
 
 #endif // LISP_H