ivn-cote · February 11, 2016 12:23 · Feb 10, 2016 · Feb 8, 2016 · Feb 1, 2016 · Feb 1, 2016
diff --git a/combinators.js b/combinators.js
@@ -2,6 +2,7 @@ const I = x => x;
 const K = x => _ => x;
 const A = f => x => f(x);
 const T = x => f => f(x);
+const W = f => x => f(x)(x);
 const C = f => y => x => f(x)(y);
 const B = f => g => x => f(g(x));
 const S = f => g => x => f(x)(g(x));

diff --git a/combinators.md b/combinators.md
@@ -4,6 +4,7 @@ identity     | **I** | id      | identity | `a → a`
 constant     | **K** | const   | always   | `a → b → a`
 apply        | **A** | ($)     | call     | `(a → b) → a → b`
 thrush       | **T** | (&)     |          | `a → (a → b) → b`
+duplication  | **W** |         |          | `(a → a → b) → a → b`
 flip         | **C** | flip    | flip     | `(a → b → c) → b → a → c`
 compose      | **B** | (.)     | compose  | `(b → c) → (a → b) → a → c`
 substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`

diff --git a/combinators.md b/combinators.md
@@ -8,6 +8,4 @@ flip         | **C** | flip    | flip     | `(a → b → c) → b → a → c`
 compose      | **B** | (.)     | compose  | `(b → c) → (a → b) → a → c`
 substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`
 psi          | **P** | on      |          | `(b → b → c) → (a → b) → a → a → c`
-fix          | **Y** | fix     |          | `(a → a) → a`
-converge     |       |         | converge | `(b -> c -> d) -> (a -> b) -> (a -> c) -> a -> d`
-useWith      |       |         | useWith  | `(b -> d -> e) -> (a -> b) -> (c -> d) -> a -> c -> e`
+fix-point    | **Y** | fix     |          | `(a → a) → a`
diff --git a/combinators.md b/combinators.md
@@ -8,6 +8,6 @@ flip         | **C** | flip    | flip     | `(a → b → c) → b → a → c`
 compose      | **B** | (.)     | compose  | `(b → c) → (a → b) → a → c`
 substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`
 psi          | **P** | on      |          | `(b → b → c) → (a → b) → a → a → c`
-fix          | **Y** | fix     |          | `(Any... -> a) f => (f -> f) -> f`
+fix          | **Y** | fix     |          | `(a → a) → a`
 converge     |       |         | converge | `(b -> c -> d) -> (a -> b) -> (a -> c) -> a -> d`
 useWith      |       |         | useWith  | `(b -> d -> e) -> (a -> b) -> (c -> d) -> a -> c -> e`
diff --git a/pointfree-factorial.js b/pointfree-factorial.js
@@ -1,7 +1,8 @@
-const {ifElse, dec} = R;
-const isZero = R.gt(1);
+const ifElse = f => g => h => x => f(x) ? g(x) : h(x);
+const isZero = a => a < 1;
 const mult = a => b => a * b;
+const dec = a => a - 1;
 
-const factorial = Y(B(ifElse(isZero, K(1)))(B(S(mult))(C(B)(dec))));
+const factorial = Y(B(ifElse(isZero)(K(1)))(B(S(mult))(C(B)(dec))));
 
-factorial(4); //> 24
+factorial(4);
diff --git a/pointfree-factorial.js b/pointfree-factorial.js
@@ -1,9 +1,3 @@
-const K = x => _ => x;
-const C = f => y => x => f(x)(y);
-const B = f => g => x => f(g(x));
-const S = f => g => x => f(x)(g(x));
-const Y = f => (g => g(g))(g => f(x => g(g)(x)));
-
 const {ifElse, dec} = R;
 const isZero = R.gt(1);
 const mult = a => b => a * b;

diff --git a/pointfree-factorial.js b/pointfree-factorial.js
@@ -0,0 +1,13 @@
+const K = x => _ => x;
+const C = f => y => x => f(x)(y);
+const B = f => g => x => f(g(x));
+const S = f => g => x => f(x)(g(x));
+const Y = f => (g => g(g))(g => f(x => g(g)(x)));
+
+const {ifElse, dec} = R;
+const isZero = R.gt(1);
+const mult = a => b => a * b;
+
+const factorial = Y(B(ifElse(isZero, K(1)))(B(S(mult))(C(B)(dec))));
+
+factorial(4); //> 24
diff --git a/combinators.md b/combinators.md
@@ -2,12 +2,12 @@ Name         | #     | Haskell | Ramda    | Signature
 ------------:|-------|---------|----------|----------
 identity     | **I** | id      | identity | `a → a`
 constant     | **K** | const   | always   | `a → b → a`
-apply        | **A** | $       | call     | `(a → b) → a → b`
-thrush       | **T** |         |          | `a → (a → b) → b`
+apply        | **A** | ($)     | call     | `(a → b) → a → b`
+thrush       | **T** | (&)     |          | `a → (a → b) → b`
 flip         | **C** | flip    | flip     | `(a → b → c) → b → a → c`
-compose      | **B** | .       | compose  | `(b → c) → (a → b) → a → c`
+compose      | **B** | (.)     | compose  | `(b → c) → (a → b) → a → c`
 substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`
 psi          | **P** | on      |          | `(b → b → c) → (a → b) → a → a → c`
-fix          | **Y** |         |          | `(Any... -> a) f => (f -> f) -> f`
+fix          | **Y** | fix     |          | `(Any... -> a) f => (f -> f) -> f`
 converge     |       |         | converge | `(b -> c -> d) -> (a -> b) -> (a -> c) -> a -> d`
 useWith      |       |         | useWith  | `(b -> d -> e) -> (a -> b) -> (c -> d) -> a -> c -> e`
diff --git a/combinators.md b/combinators.md
@@ -9,3 +9,5 @@ compose      | **B** | .       | compose  | `(b → c) → (a → b) → a → c
 substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`
 psi          | **P** | on      |          | `(b → b → c) → (a → b) → a → a → c`
 fix          | **Y** |         |          | `(Any... -> a) f => (f -> f) -> f`
+converge     |       |         | converge | `(b -> c -> d) -> (a -> b) -> (a -> c) -> a -> d`
+useWith      |       |         | useWith  | `(b -> d -> e) -> (a -> b) -> (c -> d) -> a -> c -> e`
diff --git a/fold.js b/fold.js
@@ -1,30 +0,0 @@
-//Combinators
-const I = x => x;
-
-//List manipulation
-const head = xs => xs[0];
-const tail = xs => xs.slice(1);
-const append = x => xs => [...xs, x];
-
-//Iteration
-const foldl = f => y => xs => xs.length > 0 ? foldl(f)(f(y)(head(xs)))(tail(xs)) : y;
-const foldr = f => y => xs => xs.length > 0 ? f(foldr(f)(y)(tail(xs)))(head(xs)) : y;
-const map = f => foldl(y => x => append(f(x))(y))([]);
-const filter = f => foldl(y => x => f(x) ? append(x)(y) : y)([]);
-
-//Function composition
-const compose = f => g => x => f(g(x));
-const pipe = foldr(compose)(I);
-
-//Math
-const add = a => b => a + b;
-const mult = a => b => a * b;
-const gt = a => b => b > a;
-
-//Program
-pipe([
-  map(add(1)),
-  map(mult(2)),
-  filter(gt(10))
-])
-([1, 2, 3, 4, 5, 6, 7, 8]);

diff --git a/permutations.js b/permutations.js
@@ -1,11 +0,0 @@
-const {map, join, addIndex, chain, isEmpty, insert, remove} = R;
-const cat = map(join(''));
-const ichain = addIndex(chain);
-
-//permutations :: [a] -> [[a]]
-const permutations = xs => isEmpty(xs) ? [[]] : ichain(
-  (x, i) => map(R.insert(0, x), permutations(remove(i, 1, xs))),
-  xs
-);
-
-cat(permutations(['A', 'B', 'C']));

diff --git a/reader-future.js b/reader-future.js
@@ -1,34 +0,0 @@
-console.clear();
-const then = Date.now();
-const log = x => console.log(`${Date.now() - then} - ${x}`);
-const err = x => console.log(`${Date.now() - then} - ERROR: ${x}`);
-const {K, I, pipe} = S;
-const {curry, reduce, ap, once, compose, chain, map} = R;
-const ftap = f => a => f(a).map(K(a));
-
-//A mock database
-const connect = curry(config => (log('Connecting...'), Future.of({name: 'Connection', config})))
-const close = curry(connection => Future((rej, res) => (log(`Closed ${connection.name}`), res(null))))
-const query = curry((x, connection) => Future((rej, res) => 
-  setTimeout(() => (log(`QUERY[${x}]`), res(eval(x))), 300)
-));
-
-
-const RFuture = Reader.T(Future);
-const app = RFuture(chain(query('1 + 1')));
-
-const closeConnection = () => RFuture.ask.chain(pipe([
-  chain(close),
-  RFuture.lift
-]));
-
-const querySquare = n => RFuture.ask.chain(pipe([
-  query(`${n} * ${n}`),
-  RFuture.lift
-]))
-
-app
-.chain(querySquare)
-.chain(ftap(closeConnection))
-.run(connect({foo: 'bar'}))
-.fork(err, log)

diff --git a/recursion.js → y.js b/recursion.js → y.js
diff --git a/combinators.md b/combinators.md
@@ -0,0 +1,11 @@
+Name         | #     | Haskell | Ramda    | Signature
+------------:|-------|---------|----------|----------
+identity     | **I** | id      | identity | `a → a`
+constant     | **K** | const   | always   | `a → b → a`
+apply        | **A** | $       | call     | `(a → b) → a → b`
+thrush       | **T** |         |          | `a → (a → b) → b`
+flip         | **C** | flip    | flip     | `(a → b → c) → b → a → c`
+compose      | **B** | .       | compose  | `(b → c) → (a → b) → a → c`
+substitution | **S** |         |          | `(a → b → c) → (a → b) → a → c`
+psi          | **P** | on      |          | `(b → b → c) → (a → b) → a → a → c`
+fix          | **Y** |         |          | `(Any... -> a) f => (f -> f) -> f`
diff --git a/combinators.js b/combinators.js
@@ -0,0 +1,9 @@
+const I = x => x;
+const K = x => _ => x;
+const A = f => x => f(x);
+const T = x => f => f(x);
+const C = f => y => x => f(x)(y);
+const B = f => g => x => f(g(x));
+const S = f => g => x => f(x)(g(x));
+const P = f => g => x => y => f(g(x))(g(y));
+const Y = f => (g => g(g))(g => f(x => g(g)(x)));
diff --git a/recursion.js b/recursion.js
@@ -0,0 +1,11 @@
+const head = xs => xs[0];
+const tail = xs => xs.slice(1);
+const add = a => b => a + b;
+
+const dot = Y(f => n => n < 1 ? '' : '.' + f(n - 1));
+const factorial = Y(f => n => n < 1 ? 1 : n * f(n - 1));
+const reduce = f => Y(g => y => xs => xs.length < 1 ? y : g(f(y)(head(xs)))(tail(xs)));
+
+dot(3) //> "..."
+factorial(4) //> 24
+reduce(add)(0)([1, 2, 3]) //> 6
diff --git a/y-combinator.js b/y-combinator.js
@@ -1,3 +0,0 @@
-const Y = f => (g => g(g))(g => f(x => g(g)(x)));
-const factorial = Y(f => n => n < 1 ? 1 : n * f(n - 1));
-factorial(4)

diff --git a/y-combinator.js b/y-combinator.js
@@ -0,0 +1,3 @@
+const Y = f => (g => g(g))(g => f(x => g(g)(x)));
+const factorial = Y(f => n => n < 1 ? 1 : n * f(n - 1));
+factorial(4)
diff --git a/reader-future.js b/reader-future.js
@@ -0,0 +1,34 @@
+console.clear();
+const then = Date.now();
+const log = x => console.log(`${Date.now() - then} - ${x}`);
+const err = x => console.log(`${Date.now() - then} - ERROR: ${x}`);
+const {K, I, pipe} = S;
+const {curry, reduce, ap, once, compose, chain, map} = R;
+const ftap = f => a => f(a).map(K(a));
+
+//A mock database
+const connect = curry(config => (log('Connecting...'), Future.of({name: 'Connection', config})))
+const close = curry(connection => Future((rej, res) => (log(`Closed ${connection.name}`), res(null))))
+const query = curry((x, connection) => Future((rej, res) => 
+  setTimeout(() => (log(`QUERY[${x}]`), res(eval(x))), 300)
+));
+
+
+const RFuture = Reader.T(Future);
+const app = RFuture(chain(query('1 + 1')));
+
+const closeConnection = () => RFuture.ask.chain(pipe([
+  chain(close),
+  RFuture.lift
+]));
+
+const querySquare = n => RFuture.ask.chain(pipe([
+  query(`${n} * ${n}`),
+  RFuture.lift
+]))
+
+app
+.chain(querySquare)
+.chain(ftap(closeConnection))
+.run(connect({foo: 'bar'}))
+.fork(err, log)
diff --git a/fold.js b/fold.js
@@ -1,9 +1,6 @@
 //Combinators
 const I = x => x;
 
-//Function composition
-const compose = f => g => x => f(g(x));
-
 //List manipulation
 const head = xs => xs[0];
 const tail = xs => xs.slice(1);
@@ -13,11 +10,21 @@ const append = x => xs => [...xs, x];
 const foldl = f => y => xs => xs.length > 0 ? foldl(f)(f(y)(head(xs)))(tail(xs)) : y;
 const foldr = f => y => xs => xs.length > 0 ? f(foldr(f)(y)(tail(xs)))(head(xs)) : y;
 const map = f => foldl(y => x => append(f(x))(y))([]);
+const filter = f => foldl(y => x => f(x) ? append(x)(y) : y)([]);
+
+//Function composition
+const compose = f => g => x => f(g(x));
+const pipe = foldr(compose)(I);
 
-//Lib
+//Math
 const add = a => b => a + b;
 const mult = a => b => a * b;
-const pipe = foldr(compose)(I);
+const gt = a => b => b > a;
 
 //Program
-map(pipe([add(1), mult(2)]))([1, 2, 3]);
+pipe([
+  map(add(1)),
+  map(mult(2)),
+  filter(gt(10))
+])
+([1, 2, 3, 4, 5, 6, 7, 8]);
diff --git a/permutations.js b/permutations.js
@@ -0,0 +1,11 @@
+const {map, join, addIndex, chain, isEmpty, insert, remove} = R;
+const cat = map(join(''));
+const ichain = addIndex(chain);
+
+//permutations :: [a] -> [[a]]
+const permutations = xs => isEmpty(xs) ? [[]] : ichain(
+  (x, i) => map(R.insert(0, x), permutations(remove(i, 1, xs))),
+  xs
+);
+
+cat(permutations(['A', 'B', 'C']));
diff --git a/fold.js b/fold.js
@@ -0,0 +1,23 @@
+//Combinators
+const I = x => x;
+
+//Function composition
+const compose = f => g => x => f(g(x));
+
+//List manipulation
+const head = xs => xs[0];
+const tail = xs => xs.slice(1);
+const append = x => xs => [...xs, x];
+
+//Iteration
+const foldl = f => y => xs => xs.length > 0 ? foldl(f)(f(y)(head(xs)))(tail(xs)) : y;
+const foldr = f => y => xs => xs.length > 0 ? f(foldr(f)(y)(tail(xs)))(head(xs)) : y;
+const map = f => foldl(y => x => append(f(x))(y))([]);
+
+//Lib
+const add = a => b => a + b;
+const mult = a => b => a * b;
+const pipe = foldr(compose)(I);
+
+//Program
+map(pipe([add(1), mult(2)]))([1, 2, 3]);