syntax "begin"

src/eval.c

@@ -54,6 +54,7 @@ struct Object *eval(struct Object *const object)
     struct Object *const args = object->pair.b;
 
     if (Object_is_symbol(func_expr)) {
+        if (strcmp(func_expr->s, "begin") == 0) return syntax_begin(args);
         if (strcmp(func_expr->s, "quote") == 0) return syntax_quote(args);
         if (strcmp(func_expr->s, "if")    == 0) return syntax_if(args);
     }

src/main-test.c

@@ -5,7 +5,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-// Macros
+// Syntax
+static void test_begin();
 static void test_if();
 // Lexer & parser
 static void test_arcane_SLASH_tokenize();
@@ -31,7 +32,8 @@ static void test_EQ();
 
 int main()
 {
-    // Macros
+    // Syntax
+    test_begin();
     test_if();
     // Lexer & parser
     test_arcane_SLASH_tokenize();
@@ -99,9 +101,36 @@ int main()
 }
 
 /**********
- * Macros *
+ * Syntax *
  **********/
 
+void test_begin()
+{
+    struct Object *result = NULL;
+
+    // (begin)
+    // ()
+    assert(OBJECT_IS_NULL(eval_str("(begin)")));
+
+    // (begin 123)
+    // 123
+    result = eval_str("(begin 123)");
+    assert(Object_is_number(result));
+    assert(result->i == 123);
+
+    // (begin 123 456)
+    // 456
+    result = eval_str("(begin 123 456)");
+    assert(Object_is_number(result));
+    assert(result->i == 456);
+
+    // (begin 123 456 789)
+    // 789
+    result = eval_str("(begin 123 456 789)");
+    assert(Object_is_number(result));
+    assert(result->i == 789);
+}
+
 void test_if()
 {
     struct Object *const num_123 = Object_new_number(123);

src/syntax.c

@@ -5,6 +5,18 @@
 
 #include <assert.h>
 
+struct Object *syntax_begin(struct Object *args)
+{
+    assert(OBJECT_IS_LIST_HEAD(args));
+    struct Object *result = NULL;
+    while (!OBJECT_IS_NULL(args)) {
+        assert(Object_is_pair(args));
+        result = eval(args->pair.a);
+        args = args->pair.b;
+    }
+    return result;
+}
+
 struct Object *syntax_if(struct Object *const args)
 {
     assert(Object_is_pair(args));
@@ -17,7 +29,7 @@ struct Object *syntax_if(struct Object *const args)
     assert(else_list);
     assert(Object_is_pair(else_list));
     struct Object *const else_branch = else_list->pair.a;
-    assert(else_list->pair.b == NULL);
+    assert(OBJECT_IS_NULL(else_list->pair.b));
 
     if (Object_is_false(cond)) {
         return eval(else_branch);

src/syntax.h

@@ -3,6 +3,7 @@
 
 #include "object.h"
 
+struct Object *syntax_begin(struct Object *args);
 struct Object *syntax_if(struct Object *args);
 struct Object *syntax_quote(struct Object *args);