From 6684c39cf92a0fa6c21339c6fec8a6e4cf4f463d Mon Sep 17 00:00:00 2001
From: Luke Lau <luke.lau@intel.com>
Date: Wed, 24 Jul 2019 16:20:12 +0100
Subject: [PATCH] Add WIP on passing about closures

---
 codegen.scm | 15 ++++++++++++++-
 tests.scm   |  3 +++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/codegen.scm b/codegen.scm
index 9b3878a..b403939 100644
--- a/codegen.scm
+++ b/codegen.scm
@@ -105,8 +105,21 @@
   (set! cur-lambda (+ 1 cur-lambda))
   (format "_lambda~a" (- cur-lambda 1)))
 
+(define (codegen-closure label captured si env)
+;; (define (codegen-closure label captured si env)
+;;   (let* ((stack-offsets (map (lambda (x) (- si (* x wordsize))))
+;; 			(range 0 (length captured)))
+;; 	 (inner-si (- si (* (length captured) wordsize))))
+;;     (for-each (lambda (var-name new-offset)
+;; 		(emit "movq ~a(%rbp), ~a(%rbp)" ; todo: do we need to copy this?
+;; 		      (cdr (assoc var-name env))
+;; 		      new-offset))
+;; 	      captured
+;; 	      stack-offsets)
+;; )
 					; for now we can only call closures
 (define (codegen-call closure args si env)
+;  (codegen-expr closure si env)
   (when (not (eq? (ast-type closure) 'closure))
     (error #f (format "~a is not a closure" closure)))
   (let* ((captured (caddr closure))
@@ -190,7 +203,7 @@
 (define (codegen-expr e si env)
   (case (ast-type e)
     ('builtin e)
-    ('closure e)
+    ('closure (codegen-closure (cadr e) (caddr e) si env))
     ('app
      (let ((callee (codegen-expr (car e) si env)))
        (case callee
diff --git a/tests.scm b/tests.scm
index bfd9124..168cf66 100644
--- a/tests.scm
+++ b/tests.scm
@@ -48,3 +48,6 @@
 
 (test-prog '((lambda (x y) (+ x y)) 1 2) 3)
 (test-prog '((lambda (x) (+ ((lambda (y) (+ y 1)) 3) x)) 2) 6)
+
+					; passing closures about
+(test-prog '((lambda (z) ((lambda (x) (x 1)) (lambda (y) (+ z y)))) 2) 3)
-- 
2.30.2