From 8312f289c8aaeb5e1692f7213b7730611c32300e Mon Sep 17 00:00:00 2001
From: pingu <nor@acorneroftheweb.com>
Date: Tue, 25 Nov 2025 18:18:19 +0100
Subject: [PATCH] Tehee

---
 .../Main.hs => Interpreter/Haskell.hs}        |  5 +--
 3or4/Interpreter/Self.hs                      | 42 +++++++++++++++++++
 3or4/app/Main.hs                              |  8 ++++
 3or4/chi.cabal                                |  5 ++-
 3or4/interpreter/Self.hs                      |  8 ----
 5 files changed, 55 insertions(+), 13 deletions(-)
 rename 3or4/{interpreter/Main.hs => Interpreter/Haskell.hs} (95%)
 create mode 100644 3or4/Interpreter/Self.hs
 create mode 100644 3or4/app/Main.hs
 delete mode 100644 3or4/interpreter/Self.hs

diff --git a/3or4/interpreter/Main.hs b/3or4/Interpreter/Haskell.hs
similarity index 95%
rename from 3or4/interpreter/Main.hs
rename to 3or4/Interpreter/Haskell.hs
index f2e4733..4ac06a5 100644
--- a/3or4/interpreter/Main.hs
+++ b/3or4/Interpreter/Haskell.hs
@@ -1,5 +1,6 @@
 {-# Language LambdaCase, Strict #-}
-module Main where
+
+module Interpreter.Haskell where
 
 import Chi
 import Data.Functor           ( (<&>) )
@@ -45,5 +46,3 @@ eval = runIdentity . eval'
       else lookupBranch c brs
 
 
-main :: IO ()
-main = getLine >>= print . eval . parse
diff --git a/3or4/Interpreter/Self.hs b/3or4/Interpreter/Self.hs
new file mode 100644
index 0000000..2626b17
--- /dev/null
+++ b/3or4/Interpreter/Self.hs
@@ -0,0 +1,42 @@
+{-# Language LambdaCase, Strict #-}
+
+module Interpreter.Self where
+
+import Chi
+import Interpreter.Haskell
+
+mapExp :: Exp
+mapExp = parse
+  "\\f. rec map = \\xs. case xs of \
+  \ { Nil() -> Nil() \
+  \ ; Cons(x,xs) -> Cons(f x, map xs)\
+  \ }"
+
+substBrExp :: Exp
+substBrExp = parse
+  "rec substBr = \\x. "
+
+ifExp :: Exp
+ifExp = parse
+  "\\b. \\t. \\f. case b of \
+  \ { True() -> t \
+  \ ; False() -> f \
+  \ }"
+
+equalExp :: Exp
+equalExp = parse ""
+
+substExp :: Exp
+substExp =
+  subst (Variable "if") ifExp .
+  subst (Variable "equal") equalExp .
+  subst (Variable "substBr") substBrExp .
+  subst (Variable "map") mapExp $ parse
+        "\\var. \\e. rec subst = \\x. case x of\
+        \ { Apply(e1,e2) -> Apply(subst e1, subst e2) \
+        \ ; Lambda(x,y) -> if (equal x var) Lambda(x,y) Lambda(x,subst y) \
+        \ ; Var(x) -> if (equal x var) e Var(x) \
+        \ ; Const(c,es) -> Const(c, map subst es) \
+        \ ; Rec(x, e') -> if (equal x var) Rec(x,e') Rec(x,subst e')\
+        \ ; Case(e',bs) -> _ \
+        \ }"
diff --git a/3or4/app/Main.hs b/3or4/app/Main.hs
new file mode 100644
index 0000000..de5a658
--- /dev/null
+++ b/3or4/app/Main.hs
@@ -0,0 +1,8 @@
+{-# Language LambdaCase, Strict #-}
+module Main where
+
+import Chi
+import Interpreter.Haskell
+
+main :: IO ()
+main = getLine >>= print . eval . parse
diff --git a/3or4/chi.cabal b/3or4/chi.cabal
index 6de4f5e..42807f4 100644
--- a/3or4/chi.cabal
+++ b/3or4/chi.cabal
@@ -24,14 +24,15 @@ library
     LexChi
     ParChi
     PrintChi
+    Interpreter.Haskell
+    Interpreter.Self
   hs-source-dirs:
     .
 
 executable interpreter
     main-is: Main.hs
     hs-source-dirs:
-        interpreter
-    other-modules: Self
+        app
     build-depends: base
                  , chi
                  , mtl
diff --git a/3or4/interpreter/Self.hs b/3or4/interpreter/Self.hs
deleted file mode 100644
index 127f209..0000000
--- a/3or4/interpreter/Self.hs
+++ /dev/null
@@ -1,8 +0,0 @@
--- | 
-
-module Self where
-
-import Chi
-
-substExp :: Exp
-substExp = parse ""