kzccm1d4if10m2xaz1wqy3xar821pp1r-my-site-anaphoric-git.test.suzanne.soy-0.0.1

commit 8cec548ea745ef8f6c2f69c75de189283e98f1d5
parent affa5e15a0e8dd488b835a77332d3d09bca3b03a
Author: AlexKnauth <alexander@knauth.org>
Date:   Thu, 25 Jan 2018 22:47:34 -0500

add and-let

Diffstat:
A
and-let.rkt
 | 
13
+++++++++++++
M
main.rkt
 | 
6
++++--
M
scribblings/anaphoric.scrbl
 | 
15
+++++++++++++--

3 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/and-let.rkt b/and-let.rkt
@@ -0,0 +1,13 @@
+#lang racket/base
+
+(provide and-let)
+
+(require syntax/parse/define "if-let.rkt" (for-syntax racket/base))
+
+(define-syntax and-let
+  (syntax-parser
+    [(_) #'#true]
+    [(_ body:expr) #'body]
+    [(_ [variable:id condition:expr] rest ...+)
+     #'(if-let [variable condition] (and-let rest ...) #false)]))
+
diff --git a/main.rkt b/main.rkt
@@ -16,7 +16,8 @@
                        anaphoric/acond
                        anaphoric/if-let
                        anaphoric/when-let
-                       anaphoric/cond-let))
+                       anaphoric/cond-let
+                       anaphoric/and-let))
 
 (require anaphoric/it
          anaphoric/aif
@@ -24,4 +25,5 @@
          anaphoric/acond
          anaphoric/if-let
          anaphoric/when-let
-         anaphoric/cond-let)
+         anaphoric/cond-let
+         anaphoric/and-let)
diff --git a/scribblings/anaphoric.scrbl b/scribblings/anaphoric.scrbl
@@ -122,4 +122,16 @@ using @racket[it].
 
  Each @racket[conditionᵢ] is evaluated at most once
  (evaluation stops at the first successful 
- @racket[conditionᵢ]).}
-\ No newline at end of file
+ @racket[conditionᵢ]).}
+
+@defform[(and-let [identifier condition] ... body)]{
+ Variant of @racket[and] which binds each @racket[identifier]
+ to the value of its @racket[condition], in scope within all
+ @racket[condition]s afterwards as well as in @racket[body].
+
+ Each @racket[condition] is evaluated at most once, and
+ evaluation stops at the first false condition. The
+ @racket[body] is only evaluated when all
+ @racket[conditions] are successful.
+}
+