tisp

commit ae26a50533f019d67bd620f6bec0c7703ae3eb8b
parent b5f18b6adc4966f26e522dc677cdd684c46ad24e
Author: Ed van Bruggen <edvb@uw.edu>
Date:   Tue, 31 Dec 2019 01:10:16 -0800

Have set! return new value of variable

Diffstat:
test.c
 | 
8
++++----
tibs/lib.tsp
 | 
7
++-----
tisp.c
 | 
2
+-

3 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/test.c b/test.c
@@ -169,9 +169,9 @@ char *tests[][2] = {
 	{ "foo",                         "4"     },
 	{ "(define bar foo)",            ""      },
 	{ "bar",                         "4"     },
-	{ "(set! foo 5)",                ""      },
+	{ "(set! foo 5)",                "5"     },
 	{ "foo",                         "5"     },
-	{ "(set! foo (+ foo bar))",      ""      },
+	{ "(set! foo (+ foo bar))",      "9"     },
 	{ "foo",                         "9"     },
 	{ "(define add +)",              ""      },
 	{ "(add foo bar)",               "13"    },
@@ -184,9 +184,9 @@ char *tests[][2] = {
 	{ "(define (add2 x)"
 	  "        (+ x 1) (+ x 2))",    ""      },
 	{ "(add2 2)",                    "4"     },
-	{ "(set! add2 2)",               ""      },
+	{ "(set! add2 2)",               "2"     },
 	{ "add2",                        "2"     },
-	{ "(set! add2 \"2\")",           ""      },
+	{ "(set! add2 \"2\")",           "\"2\"" },
 	{ "add2",                        "\"2\"" },
 
 	{ "lambda",                       NULL },
diff --git a/tibs/lib.tsp b/tibs/lib.tsp
@@ -203,9 +203,7 @@
   (cons val stack))
 
 (defmacro (push! stack val)
-  (list do
-        (list set! stack (list push stack val))
-        stack))
+  (list set! stack (list push stack val)))
 
 (define pop cdr)
 
@@ -225,8 +223,7 @@
 (defmacro (swap! stack)
   (list let (list (list 'x (list pop! stack))
                   (list 'y (list pop! stack)))
-        (list set! stack (list push (list push stack 'x) 'y))
-        stack))
+        (list set! stack (list push (list push stack 'x) 'y))))
 
 ;;; Math
 (define pi (* 4 (arctan 1.)))
diff --git a/tisp.c b/tisp.c
@@ -966,7 +966,7 @@ prim_set(Tsp st, Hash env, Val args)
 	if (!e || !e->key)
 		tsp_warnf("set!: variable %s is not defined", car(args)->v.s);
 	e->val = val;
-	return st->none;
+	return val;
 }
 
 /* loads tisp file or C dynamic library */