From 6af72e525c3b8ab5579fa04631a2e1244703291b Mon Sep 17 00:00:00 2001
From: Joeri Exelmans <joeri.exelmans@gmail.com>
Date: Mon, 24 Mar 2025 08:25:53 +0100
Subject: [PATCH] progress

---
 generics/generics.test.js |  6 +++++-
 main.js                   | 14 ++++++++++++--
 structures/list.js        | 16 ++++++++++++++--
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/generics/generics.test.js b/generics/generics.test.js
index afb1dc7..0917773 100644
--- a/generics/generics.test.js
+++ b/generics/generics.test.js
@@ -36,5 +36,9 @@ const weirdFnType = makeGeneric(a =>
     in: fnType({in: a, out: Int}),
     out: fnType({in: lsType(a), out: a}),
   }));
+// we call this function with parameter of type (b -> b) ...
+// giving these substitutions:
+//    a := b
+//    b := Int
 console.log("should be: [Int] -> Int");
-console.log(pretty(assign(weirdFnType, idFnType)));
\ No newline at end of file
+console.log(pretty(assign(weirdFnType, idFnType)));
diff --git a/main.js b/main.js
index 4dc5327..3f6efc6 100644
--- a/main.js
+++ b/main.js
@@ -7,6 +7,7 @@ import { Type } from './type.js';
 
 class Context {
   constructor(mod) {
+    this.mod = mod;
     this.types = new DefaultMap(() => new Set()); // instance to type
     this.instances = new DefaultMap(() => new Set()); // type to instance
 
@@ -26,11 +27,18 @@ class Context {
           this.functionsTo  .getdefault(t.params[1], true).add(fn);
         }
       }
-    }    
+    }
+  }
+
+  addToCtx({i, t}) {
+    return new Context({l:[
+      ...this.mod.l,
+      {i, t},
+    ]})
   }
 }
 
-const ctx = new Context({l:[
+let ctx = new Context({l:[
   ...ModuleStd.l,
   ...ModulePoint.l,
 ]});
@@ -257,6 +265,8 @@ async function transform(i, t) {
 async function apply(i, fn, fnT) {
   const result = fn(i);
   const resultType = fnT.params[1];
+  // update context with newly produced value
+  ctx = ctx.addToCtx({i: result, t: resultType});
   const {strI: strResult, strT: strResultType} = prettyIT({i: result, t: resultType});
   console.log(`result = ${strResult} :: ${strResultType}`);
   return instanceOrTypeOrFnOptions({i: result, t: resultType});
diff --git a/structures/list.js b/structures/list.js
index 8cffbf2..e7c7901 100644
--- a/structures/list.js
+++ b/structures/list.js
@@ -1,4 +1,4 @@
-import { typedFnType } from "./types.js";
+import { fnType, typedFnType } from "./types.js";
 import { Type } from "../type.js";
 import { Int } from "../primitives/types.js";
 import { makeGeneric } from "../generics/generics.js";
@@ -8,7 +8,7 @@ import { lsType } from "./types.js";
 const emptyList = {l:[]};
 const get = ls => i => ls.l[i];
 const put = ls => i => elem => ({l: ls.l.with(Number(i), elem)});
-// const push = ls => elem => ({l:ls.l.concat([elem])});
+const push = ls => elem => ({l:ls.l.concat([elem])});
 
 export const ModuleList = {l:[
   // Type -> Type
@@ -43,4 +43,16 @@ export const ModuleList = {l:[
             /* out */ (lsType(a))
           )
         ))),
+
+  // [a] -> a -> [a]
+  ...typedFnType(push, fnType =>
+    makeGeneric(a =>
+      fnType
+        (lsType(a))
+        (fnType
+          (a)
+          (lsType(a))
+        )
+    )
+  ),
 ]};