From ad3102e108562aa7c12e89991eb387cd3aa359ae Mon Sep 17 00:00:00 2001
From: Ben Sima <ben@bsima.me>
Date: Wed, 10 Feb 2021 18:04:12 -0500
Subject: Add boolean and logging pipeline operators

---
 Alpha.hs | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

(limited to 'Alpha.hs')

diff --git a/Alpha.hs b/Alpha.hs
index 697f096..8fdca51 100644
--- a/Alpha.hs
+++ b/Alpha.hs
@@ -42,12 +42,17 @@ module Alpha
     (<%),
     (%>),
 
-    -- * inding
+    -- * Binding
     bind,
     (+>),
 
     -- * Bool
     don't,
+    (?>),
+    (?<),
+    (?:),
+    (?.),
+    (?+),
 
     -- * Text
     tshow,
@@ -66,9 +71,6 @@ module Alpha
 
     -- * Data Validation
     require,
-
-    -- * Debugging tools
-    say,
   )
 where
 
@@ -85,10 +87,6 @@ import qualified Prelude
 list :: a -> [a]
 list a = [a]
 
--- | Debugging printf
-say :: Text -> IO ()
-say = putText
-
 -- | Composition
 compose :: (a -> b) -> (b -> c) -> (a -> c)
 compose f g x = g (f x)
@@ -163,6 +161,27 @@ a +> b = a Prelude.>>= b
 
 infixl 1 +>
 
+-- | If-then-else. wutcol
+(?:) :: Bool -> (Bool -> p, Bool -> p) -> p
+a ?: (f, g) = if a then f a else g a
+
+-- | Inverted if-then-else. wutdot
+(?.) :: Bool -> (Bool -> p, Bool -> p) -> p
+a ?. (g, f) = if a then f a else g a
+
+-- | Positive assertion. wutgar
+(?>) :: Bool -> (Bool -> Text -> a) -> Text -> a
+a ?> f = if a then f a else panic "wutgar failed"
+
+-- | Lisp-style cond. wutlus
+(?+) :: t -> [(t -> Bool, p)] -> p
+a ?+ ((p, v) : ls) = if p a then v else a ?+ ls
+_ ?+ [] = panic "wutlus: empty cond list"
+
+-- | Negative assertion. wutgal
+(?<) :: Bool -> (Bool -> Text -> a) -> Text -> a
+a ?< f = if not a then f a else panic "wutgal failed"
+
 -- | Removes newlines from text.
 chomp :: Text -> Text
 chomp = Text.filter (/= '\n')
-- 
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