From aa7a034368d146ec94f3dd4c87b9bfbc57bbaca1 Mon Sep 17 00:00:00 2001
From: Dustin Swan <dustin@dustinswan.com>
Date: Mon, 2 Feb 2026 22:44:40 -0700
Subject: [PATCH] More stdlib fun

---
 src/main.ts   |  1 +
 src/stdlib.cg | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/test.cg   | 41 ++++++++++++++++++++++++++++++++++++--
 3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/src/main.ts b/src/main.ts
index 3aacc27..2b3d904 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -24,6 +24,7 @@ console.log(ast);
 const env: Env = new Map(Object.entries(builtins));
 const res = evaluate(ast, env);
 console.log(res);
+
 /*
 const appRecord = evaluate(ast, env);
 
diff --git a/src/stdlib.cg b/src/stdlib.cg
index fd8f575..dd450c2 100644
--- a/src/stdlib.cg
+++ b/src/stdlib.cg
@@ -1,9 +1,64 @@
+# map : (a \ b) \ List a \ List b
 map = f list \ list
   | [] \ []
   | [x, ...xs] \ [f x, ...map f xs];
 
+# filter : (a \ Bool) \ List a \ List a
 filter = f list \ list
   | [] \ []
   | [x, ...xs] \ (f x
       | True \ [x, ...filter f xs]
       | False \ filter f xs);
+
+# fold : (b \ a \ b) \ b \ List a \ b
+fold = f acc list \ list
+  | [] \ acc
+  | [x, ...xs] \ fold f (f acc x) xs;
+
+# reverse : List a \ List a
+reverse = list \ list
+  | [] \ []
+  | [x, ...xs] \ (reverse xs) & [x];
+
+# take : Int \ List a \ List a
+take = n list \ { n = n, list = list }
+  | { n = _, list = [] } \ []
+  | { n = 0, list = _ } \ []
+  | { n = _, list = [x, ...xs] } \ [x, ...take (n - 1) xs];
+
+# drop : Int \ List a \ List a
+drop = n list \ { n = n, list = list }
+  | { n = _, list = [] } \ []
+  | { n = 0, list = _ } \ list
+  | { n = _, list = [x, ...xs] } \ drop (n - 1) xs;
+
+# zipWith = (a \ b \ c) List a \ List b \ List c
+zipWith = f l1 l2 \ l1
+  | [] \ []
+  | [x, ...xs] \ (l2
+    | [] \ []
+    | [y, ...ys] \ [f x y, ...zipWith f xs ys]);
+
+# and : Bool \ Bool \ Bool
+and = x y \ x
+  | False \ False
+  | True \ (y | False \ False | True \ True);
+
+# or : Bool \ Bool \ Bool
+or = x y \ x
+  | True \ True
+  | False \ (y | True \ True | False \ False);
+
+# not = Bool \ Bool
+not = x \ x
+  | True \ False
+  | False \ True;
+
+# isSome = maybe \ ...
+# isNone = maybe \ ...
+# unwrapOr = default maybe \ ...
+
+# range = start end \ ... # [start, start+1, ..., end-1]
+# sum = list \ ...
+# any = f list \ ...
+# all = f list \ ...
diff --git a/src/test.cg b/src/test.cg
index 4795b8c..de67e0a 100644
--- a/src/test.cg
+++ b/src/test.cg
@@ -1,7 +1,44 @@
+list = [1, 2, 3, 4, 5];
+
 add1 = x \ x + 1;
 
-mapped = map add1 [1, 2, 3, 4, 5];
+mapped = map add1 list;
 
 isEven = x \ x % 2 == 0;
 
-filter isEven mapped
+sumList = list \ fold add 0 list;
+
+filtered = filter isEven mapped;
+
+summed = sumList mapped;
+
+l = len list;
+
+reversed = reverse list;
+
+take3 = take 3 list;
+
+drop3 = drop 3 list;
+
+list2 = [6, 7, 8];
+
+zipped = zipWith add list list2;
+
+anded = and True False;
+
+ored = or True False;
+
+notted = not False;
+
+{
+  filtered = filtered,
+  summed = summed,
+  l = l,
+  reversed = reversed,
+  take3 = take3,
+  drop3 = drop3,
+  zipped = zipped,
+  anded = anded,
+  ored = ored,
+  notted = notted
+}