add dispatch methods

.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+

package-lock.json

@@ -0,0 +1,22 @@
+{
+  "name": "izuna",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "izuna",
+      "version": "1.0.0",
+      "license": "GPL-3.0-or-later",
+      "devDependencies": {
+        "folktest": "git+https://git.kitsu.cafe/rowan/folktest.git"
+      }
+    },
+    "node_modules/folktest": {
+      "version": "1.0.0",
+      "resolved": "git+https://git.kitsu.cafe/rowan/folktest.git#708d44f1215be33fcceba426029f44b4f963dbe5",
+      "dev": true,
+      "license": "GPL-3.0-or-later"
+    }
+  }
+}

package.json

@@ -5,9 +5,12 @@
   "type": "module",
   "main": "src/index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "./test/index.js"
   },
   "keywords": [],
   "license": "GPL-3.0-or-later",
-  "description": ""
+  "description": "",
+  "devDependencies": {
+    "folktest": "git+https://git.kitsu.cafe/rowan/folktest.git"
+  }
 }

src/fantasy-land.js

@@ -1,6 +1,8 @@
+import { isArray, isFn } from './type.js'
+import { last } from './list.js'
 /**
  * @param {PropertyKey[]} methods 
- * @param {Fn} f
+ * @param {import('./types.js').Fn} f
  */
 export function dispatch(methods, f) {
   return function() {
@@ -12,7 +14,8 @@ export function dispatch(methods, f) {
     const obj = last(args)
 
     if (!isArray(obj)) {
-      for (let i = 0; i < obj.length; i++) {
+      const len = methods.length
+      for (let i = 0; i < len; i++) {
         const fn = obj[methods[i]]
         if (isFn(fn)) {
           return fn.apply(obj, args.slice(0, -1))

src/function.js

@@ -1,5 +1,6 @@
 import { curry, curryN } from './curry.js'
-import { concat, iter } from './list.js'
+import { dispatch } from './fantasy-land.js'
+import { concat as iconcat, iter } from './list.js'
 
 /** @import { Fn, Morphism, InferredMorphism, Predicate } from './types.js' */
 
@@ -16,7 +17,11 @@ export const id = x => x
  */
 export const pipe = (...fns) => x => fns.reduce((v, f) => f(v), x)
 
-export const compose = curry(
+export const concat = curry(dispatch(['fantasy-land/concat', 'concat'],
+  (b, a) => iconcat(iter(a), iter(b))
+))
+
+export const compose = curry(dispatch(['fantasy-land/compose', 'compose'],
   /**
    * @template T, U, V
    * @param {Morphism<U, V>} f
@@ -25,7 +30,7 @@ export const compose = curry(
    * @returns V
    */
   (f, g, x) => chain(g, chain(f, x))
-)
+))
 
 /**
  * @template T
@@ -107,7 +112,7 @@ export const unless = curry(
  * @typedef {(f: F, a: A) => B} StaticMorphism
  */
 
-export const ap = curry(
+export const ap = curry(dispatch(['fantasy-land/ap', 'ap'],
   /**
     * @template A, B
     * @template {Morphism<A, B>} Ap
@@ -115,7 +120,7 @@ export const ap = curry(
     * @param {{ ap: Ap } | Ap} a
     */
   (f, a) => {
-    const fs = liftA(dispatchF('ap', f))
+    const fs = liftA(f)
     const args = liftA(a)
 
     const xs = fs.reduce((acc, f) => (
@@ -123,16 +128,17 @@ export const ap = curry(
     ), [])
 
     return [...xs]
-  })
+  }))
 
-export const chain = curry(
-  function chain(f, a) {
-  })
+export const chain = curry(dispatch(['fantasy-land/chain', 'chain'],
+  (f, a) => a.map(f)
+))
 
-export const map = curry((f, a) => {
-})
+export const map = curry(dispatch(['fantasy-land/map', 'map'],
+  (f, a) => a.map(f)
+))
 
-export const reduce = curry((f, acc, xs) => {
-
-})
+export const reduce = curry(dispatch(['fantasy-land/reduce', 'reduce'],
+  (f, acc, xs) => xs.reduce(f, acc)
+))
 

test/index.js

@@ -0,0 +1,7 @@
+#!/usr/bin/env node
+
+import { TerminalRunner } from 'folktest'
+import * as Tests from './units/index.js'
+
+console.log(TerminalRunner(Tests).toString())
+

test/units/index.js

@@ -0,0 +1,16 @@
+import { it, assert } from 'folktest'
+import { dispatch } from '../../src/fantasy-land.js'
+
+const obj = {
+  'test': a => console.log('test', a)
+}
+
+export const Tests = [
+  it('whatever', () => {
+    const f = dispatch(['fantasy-land/test', 'test'], (f, a) => {
+      console.log(f, a)
+    })
+    console.log(f(1, obj))
+  })
+]
+