From 2cda9b946d701faa308b0915c83ea48fb94d94af Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Tue, 11 Oct 2022 23:05:16 -0700
Subject: structs: optional init-exprs now useful in :delegate

* stdlib/struct.tl (:delegate): Handle the two-element
form of the optional parameter, which specifies the
usual initializing expression for the default value.
This is just passed through as-is to the generated
method.  Diagnose if the three-element form occurs.

* tests/012/oop.tl: Some new tests.

* txr.1: Documented.
---
 stdlib/struct.tl | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

(limited to 'stdlib/struct.tl')

diff --git a/stdlib/struct.tl b/stdlib/struct.tl
index d373c330..10b07710 100644
--- a/stdlib/struct.tl
+++ b/stdlib/struct.tl
@@ -427,9 +427,19 @@
          (pp (new (fun-param-parser (cdr params) form)))
          (opt pp.(opt-syms))
          (args (append pp.req opt pp.rest)))
-    ^((:method ,meth-name (,obj ,*pp.req
-                           ,*(if opt (cons : (mapcar (lop list :) opt)))
-                           ,*pp.rest)
+    ^((:method ,meth-name
+        (,obj ,*pp.req
+              ,*(if opt
+                  (cons : (collect-each ((o pp.opt))
+                            (tree-case o
+                              ((sym) ^(,sym :))
+                              ((sym init) o)
+                              ((sym init sym-p)
+                               (compile-error form
+                                              "~s: three-element optional \ \
+                                              parameter ~s not supported"
+                                              o))))))
+              ,*pp.rest)
         (qref ,delegate-expr (,target-method ,*args))))))
 
 (define-struct-clause :mass-delegate (:form form self-var delegate-expr
-- 
cgit v1.2.3