From c2b63ff77961065191e6e31f98abf540dda2e845 Mon Sep 17 00:00:00 2001
From: rowan <rowan@kitsu.cafe>
Date: Mon, 31 Mar 2025 13:37:15 -0500
Subject: [PATCH] fix Construct<T>, add bimap to result

---
 src/algebra/common.js | 11 ++++++-----
 src/algebra/option.js |  4 ++--
 src/algebra/result.js | 39 ++++++++++++++++++++++++++++++++-------
 3 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/src/algebra/common.js b/src/algebra/common.js
index 2a40692..890458d 100644
--- a/src/algebra/common.js
+++ b/src/algebra/common.js
@@ -15,7 +15,8 @@ export function constant() { return this }
 
 /**
  * @template T
- * @typedef {{ [Self]: (value: T) => Applicative<T> }} Applicative
+ * @this {Construct<T>}
+ * @typedef {{ [Self]: <a>(value: a) => Construct<a> }} Construct
  */
 
 /**
@@ -44,10 +45,10 @@ export function extract() {
 }
 
 /**
- * @template T
- * @this {Applicative<T>}
- * @param {T} value 
- * @returns {Applicative<T>}
+ * @template T, U
+ * @this {Construct<T>}
+ * @param {U} value 
+ * @returns {Construct<U>}
  */
 export function of(value) {
   return this[Self](value)
diff --git a/src/algebra/option.js b/src/algebra/option.js
index 1187cf5..1d32cf7 100644
--- a/src/algebra/option.js
+++ b/src/algebra/option.js
@@ -1,6 +1,6 @@
 import { chain, constant, Self, Value } from './common.js'
 
-/** @import { Applicative, Morphism, Set } from './common.js' */
+/** @import { Construct, Morphism, Set } from './common.js' */
 
 /**
  * @template T
@@ -20,7 +20,7 @@ import { chain, constant, Self, Value } from './common.js'
 
 /**
  * @template T
- * @typedef {Applicative<T> & Set<T> & SomeMethods<T>} Some
+ * @typedef {Construct<T> & Set<T> & SomeMethods<T>} Some
  * @variation 1
  */
 
diff --git a/src/algebra/result.js b/src/algebra/result.js
index f387be2..64f1448 100644
--- a/src/algebra/result.js
+++ b/src/algebra/result.js
@@ -1,6 +1,6 @@
 import { chain, constant, Self, Value } from './common.js'
 
-/** @import { Morphism } from './common.js' */
+/** @import { Construct, Morphism, Set } from './common.js' */
 
 /**
  * @template T, E
@@ -9,24 +9,36 @@ import { chain, constant, Self, Value } from './common.js'
 
 /**
  * @template T
- * @typedef Ok
+ * @typedef OkMethods
  * @property {typeof isOk} isOk
  * @property {typeof isErr} isErr
  * @property {typeof chain} chain
  * @property {typeof map} map
  * @property {typeof alt} alt
  * @property {typeof fold} fold
+ * @property {typeof bimap} bimap
  */
 
 /**
  * @template T
- * @typedef Err
+ * @typedef {Set<T> & Construct<T> & OkMethods<T>} Ok
+ */
+
+/**
+ * @template T
+ * @typedef ErrMethods
  * @property {typeof isOk} isOk
  * @property {typeof isErr} isErr
  * @property {typeof chain} chain
  * @property {typeof map} map
  * @property {typeof alt} alt
  * @property {typeof fold} fold
+ * @property {typeof bimap} bimap
+ */
+
+/**
+ * @template T
+ * @typedef {Set<T> & Construct<T> & ErrMethods<T>} Err
  */
 
 /**
@@ -36,13 +48,24 @@ import { chain, constant, Self, Value } from './common.js'
  * @returns {Result<U, E>}
  */
 function map(fn) {
-  return this[Self](this.chain(fn))
+  return /** @type {Result<U, E>} */ (this[Self](this.chain(fn)))
+}
+
+/**
+ * @template T1, T2, E1, E2
+ * @this {Result<T1, E1>}
+ * @param {Morphism<T1, T2>} y
+ * @param {Morphism<E1, E2>} x
+ * @returns {Result<T2, E2>}
+ */
+function bimap(x, y) {
+  return map.call(this, y).map(x)
 }
 
 /**
  * @template T, U, E
  * @this {Result<T, E>}
- * @param {Morphism<T, Result<U, E>>} fn 
+ * @param {Morphism<T, U>} fn 
  * @param {U} acc 
  * @return {U}
  */
@@ -92,7 +115,8 @@ export const Ok = value => Object.freeze({
   chain,
   map,
   alt,
-  fold
+  fold,
+  bimap
 })
 
 /**
@@ -108,7 +132,8 @@ export const Err = value => Object.freeze({
   alt,
   isOk,
   isErr,
-  fold
+  fold,
+  bimap
 })
 
 /**