ISO conforming lambda

1 files changed, 33 insertions, 0 deletions

diff --git a/src/proc.c b/src/proc.c
index c64bb88ac..98f753ac6 100644
--- a/src/proc.c
+++ b/src/proc.c
@@ -59,6 +59,7 @@ mrb_proc_new_cfunc(mrb_state *mrb, mrb_func_t func)
 static inline void
 proc_copy(struct RProc *a, struct RProc *b)
 {
+  a->flags = b->flags;
   a->body = b->body;
   a->target_class = b->target_class;
   a->env = b->env;
@@ -111,6 +112,35 @@ mrb_proc_iseq(mrb_state *mrb, struct RProc *p)
   return p->body.irep->iseq;
 }
 
+/* 15.3.1.2.6  */
+/* 15.3.1.3.27 */
+/*
+ * call-seq:
+ *   lambda { |...| block }  -> a_proc
+ *
+ * Equivalent to <code>Proc.new</code>, except the resulting Proc objects
+ * check the number of parameters passed when called.
+ */
+static mrb_value
+proc_lambda(mrb_state *mrb, mrb_value self)
+{
+  mrb_value blk;
+  struct RProc *p;
+
+  mrb_get_args(mrb, "&", &blk);
+  if (mrb_nil_p(blk)) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "tried to create Proc object without a block");
+  }
+  p = mrb_proc_ptr(blk);
+  if (!MRB_PROC_STRICT_P(p)) {
+    struct RProc *p2 = (struct RProc*)mrb_obj_alloc(mrb, MRB_TT_PROC, p->c);
+    proc_copy(p2, p);
+    p2->flags |= MRB_PROC_STRICT;
+    return mrb_obj_value(p2);
+  }
+  return self;
+}
+
 void
 mrb_init_proc(mrb_state *mrb)
 {
@@ -136,4 +166,7 @@ mrb_init_proc(mrb_state *mrb)
   m = mrb_proc_new(mrb, call_irep);
   mrb_define_method_raw(mrb, mrb->proc_class, mrb_intern(mrb, "call"), m);
   mrb_define_method_raw(mrb, mrb->proc_class, mrb_intern(mrb, "[]"), m);
+
+  mrb_define_class_method(mrb, mrb->kernel_module, "lambda", proc_lambda, ARGS_NONE());    /* 15.3.1.2.6  */
+  mrb_define_method(mrb, mrb->kernel_module,       "lambda", proc_lambda, ARGS_NONE());    /* 15.3.1.3.27 */
 }