From 47bf6786cc7ee82dfcdf29a31a6dde3a8e83f93b Mon Sep 17 00:00:00 2001
From: digikar <shubhamkarayare@gmail.com>
Date: Sat, 27 Jul 2024 00:01:23 +0530
Subject: [PATCH] [add] pyfor iterate clause

---
 py4cl2-cffi.asd  |  1 +
 src/iterate.lisp | 19 +++++++++++++++++++
 src/package.lisp |  4 +++-
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 src/iterate.lisp

diff --git a/py4cl2-cffi.asd b/py4cl2-cffi.asd
index a2c779b..0b2a6dd 100644
--- a/py4cl2-cffi.asd
+++ b/py4cl2-cffi.asd
@@ -55,6 +55,7 @@
                (:file "arg-list")
                (:file "import-export")
                (:file "lisp-classes")
+               (:file "iterate")
                (:file "do-after-load"))
   :perform (test-op (o c)
              (declare (ignore o c))
diff --git a/src/iterate.lisp b/src/iterate.lisp
new file mode 100644
index 0000000..a41eb3b
--- /dev/null
+++ b/src/iterate.lisp
@@ -0,0 +1,19 @@
+(in-package :py4cl2-cffi)
+
+(declaim (inline pyerror-stop-iteration-p))
+(defun pyerror-stop-iteration-p (simple-pyerror)
+  (declare (optimize speed)
+           (type simple-pyerror simple-pyerror))
+  (string= "StopIteration" (slot-value simple-pyerror 'type)))
+
+(deftype pyerror-stop-iteration ()
+  `(and simple-pyerror
+        (satisfies pyerror-stop-iteration-p)))
+
+(defmacro-clause (PYFOR var IN pyobject-wrapper)
+  ;; TODO: Tests and docstrings
+  (let ((pygen (gensym "PYGENERATOR")))
+    `(progn
+       (with ,pygen = (pycall "iter" ,pyobject-wrapper))
+       (for ,var = (handler-case (pycall "next" ,pygen)
+                     (pyerror-stop-iteration () (finish)))))))
diff --git a/src/package.lisp b/src/package.lisp
index e9a1309..347c0e2 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -66,6 +66,8 @@
            #:+py-none-pointer+
 
            #:python-getattr
-           #:python-setattr))
+           #:python-setattr
+
+           #:pyfor))
 
 (in-package :py4cl2-cffi)