From cff5a0dfa89ab3a7f95512382cedf88f8e1709d1 Mon Sep 17 00:00:00 2001
From: Jan Tuomi <jans.tuomi@gmail.com>
Date: Fri, 9 Dec 2022 18:16:41 +0200
Subject: Fix purity issue

---
 core/common.milch | 7 +++++--
 core/result.milch | 7 +++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

(limited to 'core')

diff --git a/core/common.milch b/core/common.milch
index cddf02f..2dc6698 100644
--- a/core/common.milch
+++ b/core/common.milch
@@ -1,8 +1,11 @@
 ;; Control flow
 ;;;;;;;;;;;;;;;;;;;;;;;;;
 
-(let . (\[f g]
-    (\[x] (f (g x)))))
+; function composition
+(let . (\[f g x] (f (g x))))
+
+; impure version of .
+(let .! (\![f g x] (f (g x))))
 
 (let flow (\[fs]
     (foldr . id (reverse fs))))
diff --git a/core/result.milch b/core/result.milch
index f122ee6..903ca38 100644
--- a/core/result.milch
+++ b/core/result.milch
@@ -1,3 +1,5 @@
+(import "core/common")
+
 (record Result/Ok value)
 (record Result/Ex value)
 
@@ -23,3 +25,8 @@
     (match (kind m)
         :Result/Ok (Result/Ok/get-value m)
         :Result/Ex (catch-f (Result/Ex/get-value m)))))
+
+; converts the given impure function that can throw a fatal error
+; to an impure function that returns a Result
+(let Result/safe! (\![fn! arg]
+    (try! Result/ex (.! Result/ok fn!) arg)))
-- 
cgit v1.3