[pypy-commit] stmgc default: implement pair?

[fijal]

Author: Maciej Fijalkowski <fijall at gmail.com>
Branch: 
Changeset: r377:ffe6884d33a4
Date: 2013-07-09 11:33 +0200
http://bitbucket.org/pypy/stmgc/changeset/ffe6884d33a4/

Log:	implement pair?

diff --git a/duhton/demo/trees.duh b/duhton/demo/trees.duh
--- a/duhton/demo/trees.duh
+++ b/duhton/demo/trees.duh
@@ -1,6 +1,6 @@
 
 (defun create-tree (n)
-   (if (== n 0) (cons 1) (cons (create-tree (- n 1)) (create-tree (- n 1))))
+   (if (== n 0) 1 (cons (create-tree (- n 1)) (create-tree (- n 1))))
 )
 
 (defun walk-tree (tree)
diff --git a/duhton/glob.c b/duhton/glob.c
--- a/duhton/glob.c
+++ b/duhton/glob.c
@@ -588,6 +588,16 @@
     return DuInt_FromInt(res != NULL);
 }
 
+DuObject *du_pair(DuObject *cons, DuObject *locals)
+{
+    _du_read1(cons);
+    if (cons == Du_None || _DuCons_NEXT(cons) != Du_None)
+        Du_FatalError("pair?: expected one argument");
+
+    DuObject *ob = _DuCons_CAR(cons);
+	return DuInt_FromInt(DuCons_Check(ob));
+}
+
 DuObject *du_assert(DuObject *cons, DuObject *locals)
 {
     DuObject *obj;
@@ -640,6 +650,7 @@
     DuFrame_SetBuiltinMacro(Du_Globals, "transaction", du_transaction);
     DuFrame_SetBuiltinMacro(Du_Globals, "sleepms", du_sleepms);
     DuFrame_SetBuiltinMacro(Du_Globals, "defined?", du_defined);
+	DuFrame_SetBuiltinMacro(Du_Globals, "pair?", du_pair);
     DuFrame_SetBuiltinMacro(Du_Globals, "assert", du_assert);
     DuFrame_SetSymbolStr(Du_Globals, "None", Du_None);
 }
diff --git a/duhton/test/test_cons.py b/duhton/test/test_cons.py
--- a/duhton/test/test_cons.py
+++ b/duhton/test/test_cons.py
@@ -7,6 +7,10 @@
     assert run("(print (quote (1 2 3)))") == "( 1 2 3 )\n"
     assert run("(print (cons 1 2))") == "( 1 . 2 )\n"
 
+def test_pair():
+    assert run("(print (pair? 1))") == "0\n"
+    assert run("(print (pair? (cons 1 2)))") == "1\n"
+
 def test_car_cdr():
     assert run("(print (car (quote (2 3))))") == "2\n"
     assert run("(print (cdr (quote (2 3))))") == "( 3 )\n"