hughfdjackson

// Gate takes three Observables.
// gateFlag$: an Observable of booleans
// open$:     an Observable of values
// closed$:   an Observable of values

var gate = function(gateFlag$, open$, closed$) { 
  ... 
};

// Use Case: 

hughfdjackson

var composeBack = function(nb2, nb1){ 
  return function(input, cb){ 
    nb1(input, function(err, val1) { 
      if (err) return cb(err);
      else nb2(val1, function(err, val){
        if (err) return cb(err); 
        else cb(undefined, val)
      })
    });
  }

hughfdjackson

import Text.Parsec
import Text.Parsec.String
import Control.Applicative hiding (many, (<|>))

data Calc = Number Float
          | OpPlus Calc Calc
          | OpMult Calc Calc
          | OpSubt Calc Calc
          | OpDivd Calc Calc
          

hughfdjackson

*Main> 1 / 2 + 3 * 34 / 3 - 343 * 3 / 34 * 34
-994.5
*Main> intr "1 / 2 + 3 * 34 / 3 - 343 * 3 / 34 * 34"
Right (-994.5)

hughfdjackson

Building dust-0.1.0.0...
Preprocessing executable 'dust' for dust-0.1.0.0...
Preprocessing test suite 'tests' for dust-0.1.0.0...
[2 of 4] Compiling Language.Parse   ( src/Language/Parse.hs, dist/build/tests/tests-tmp/Language/Parse.o )

src/Language/Parse.hs:17:12:
    No instance for (Stream s m Char) arising from a use of ‘oneOf’
    In a stmt of a 'do' block: first <- oneOf alpha
    In the expression:
      do { first <- oneOf alpha;

hughfdjackson

- + Errors (1)
 `-- tutorial.idr line 24 col 20:
     When elaborating right hand side of vectormanip.reverse, reverseAcc:
     Can't unify
             Vect (m + S n) a
     with
             Vect (S (plus m n)) a
     
     Specifically:
             Can't unify

hughfdjackson

> var clone = _.partial(_.extend, {})
undefined

> clone({ x: 3, y: 3 })
Object { x: 3, y: 3 }

> clone({ x: 3 })
Object { x: 3, y: 3 }

hughfdjackson

-- proving that these are equivalent
sPlusAssoc : (m, n: Nat) -> S (m + n) = plus m (S n)
sPlusAssoc Z n = refl
sPlusAssoc (S m) n = rewrite sPlusAssoc m n in refl


-- want to use the proof here
total concat : Vect n a -> Vect m a -> Vect (m + n) a
concat (x :: xs) ys = x :: (concat xs ys)
concat Nil ys = ys

hughfdjackson

sPlusAssoc : (m, n: Nat) -> S (m + n) = plus m (S n)
sPlusAssoc Z     n = refl
sPlusAssoc (S m) n = rewrite sPlusAssoc m n in refl

total concat : Vect n a 
            -> Vect m a 
            -> Vect (m + n) a
concat {a=a} {m=m} {n=n} (x :: xs) ys = replace {P = \k => Vect k a} (sPlusAssoc m n) (x :: concat xs ys)
concat Nil       ys = replace sPlusAssoc $ ys

hughfdjackson

sPlusAssoc : (m, n: Nat) -> S (m + n) = plus m (S n)
sPlusAssoc Z     n = refl
sPlusAssoc (S m) n = rewrite sPlusAssoc m n in refl

total concat : Vect n a 
            -> Vect m a 
            -> replace {P = \k => Vect k a} (sPlusAssoc m n) (Vect (m + n) a)
concat (x :: xs) ys = x :: (concat xs ys)
concat nil       ys = ys