From 1ecc2c62041d79ea04383eca10244b8d411ce0d9 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sun, 5 Mar 2023 17:26:52 +0100
Subject: Way faster recursive show

---
 samples/io/reverse.bruijn |  2 --
 src/Helper.hs             | 28 +++++++++++++++++++---------
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/samples/io/reverse.bruijn b/samples/io/reverse.bruijn
index d5a0597..7a3553f 100644
--- a/samples/io/reverse.bruijn
+++ b/samples/io/reverse.bruijn
@@ -1,8 +1,6 @@
 # "echo tacocat | bruijn reverse.bruijn"
 
 :import std/List .
-:import std/Combinator .
-:import std/Monad .
 
 # stdin is encoded as binary numbers in a list
 # reversing the list reverses the input!
diff --git a/src/Helper.hs b/src/Helper.hs
index 110fd4f..33bfd69 100644
--- a/src/Helper.hs
+++ b/src/Helper.hs
@@ -127,15 +127,25 @@ instance Show Mixfix where
 -- TODO: Remove Application and replace with Chain (renaming of MixfixChain)
 data Expression = Bruijn Int | Function Identifier | Abstraction Expression | Application Expression Expression | MixfixChain [Mixfix] | Prefix Identifier Expression
   deriving (Ord, Eq)
-instance Show Expression where
-  show (Bruijn      x    ) = "\ESC[91m" <> show x <> "\ESC[0m"
-  show (Function    ident) = "\ESC[95m" <> show ident <> "\ESC[0m"
-  show (Abstraction e    ) = "\ESC[36m[\ESC[0m" <> show e <> "\ESC[36m]\ESC[0m"
-  show (Application exp1 exp2) =
-    "\ESC[33m(\ESC[0m" <> show exp1 <> " " <> show exp2 <> "\ESC[33m)\ESC[0m"
-  show (MixfixChain ms) =
-    "\ESC[33m(\ESC[0m" <> (intercalate " " $ map show ms) <> "\ESC[33m)\ESC[0m"
-  show (Prefix p e) = show p <> " " <> show e
+instance Show Expression where -- TODO: make use of precedence value?
+  showsPrec _ (Bruijn x) =
+    showString "\ESC[91m" . shows x . showString "\ESC[0m"
+  showsPrec _ (Function ident) =
+    showString "\ESC[95m" . shows ident . showString "\ESC[0m"
+  showsPrec _ (Abstraction e) =
+    showString "\ESC[36m[\ESC[0m" . showsPrec 0 e . showString
+      "\ESC[36m]\ESC[0m"
+  showsPrec _ (Application exp1 exp2) =
+    showString "\ESC[33m(\ESC[0m"
+      . showsPrec 0 exp1
+      . showString " "
+      . showsPrec 0 exp2
+      . showString "\ESC[33m)\ESC[0m"
+  showsPrec _ (MixfixChain ms) =
+    showString "\ESC[33m(\ESC[0m"
+      . foldr (.) id (map (showsPrec 0) ms)
+      . showString "\ESC[33m)\ESC[0m"
+  showsPrec _ (Prefix p e) = shows p . showString " " . showsPrec 0 e
 data Command = Input String | Watch String | Import String String | Test Expression Expression | ClearState | Time Expression
   deriving (Show)
 data Instruction = Define Identifier Expression [Instruction] | Evaluate Expression | Comment | Commands [Command] | ContextualInstruction Instruction String
-- 
cgit v1.2.3