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Ramda stuff
var R = require('ramda');
var states = [
{symbol: 'CT', name: 'Connecticut', pop: 3574097},
{symbol: 'ME', name: 'Maine', pop: 1328361},
{symbol: 'MA', name: 'Massachusetts', pop: 6547629},
{symbol: 'NH', name: 'New Hampshire', pop: 1316470},
{symbol: 'RI', name: 'Rhode Island', pop: 1052567},
{symbol: 'VT', name: 'Vermont', pop: 623741},
];
var notSmall = (state) => state.pop >= 2000000;
R.reduce((accum, state) => notSmall(state) ?
R.assoc(state.symbol, state.pop, accum) :
accum,
{}, states); //=> {"CT": 3574097, "MA": 6547629}
R.pipe(
R.filter(notSmall),
R.map(R.props(['symbol', 'pop'])),
R.fromPairs)(states) //=> {"CT": 3574097, "MA": 6547629}
R.reduce((accum, state) => notSmall(state) ? R.assoc(state.symbol, state.pop, accum) : accum, {}, states);
R.pipe(
R.filter(notSmall),
R.map(R.props(['symbol', 'pop'])),
R.fromPairs)(states);
R.fromPairs(R.map(R.props(['symbol', 'pop']), R.filter(notSmall, states)))
R.fromPairs([[ 'CT', 3574097 ]])
R.pipe(R.props(['symbol', 'pop']), R.fromPairs)([ 'CT', 3574097 ]);
R.map(R.pipe(R.props(['symbol', 'pop']), R.fromPairs), R.filter(notSmall, states));
// Path
R.path(['a', 'b'], {a: {b: 2}});
// Combining functions
const isEven = x => x % 2 === 0
R.find(isEven, [1, 2, 3, 4])
R.find(R.complement(isEven), [1, 2, 3, 4])
R.filter(isEven, [1, 2, 3, 4])
R.filter(R.complement(isEven), [1, 2, 3, 4])
// Both/ Either/ Curry
var wasBornInCountry = R.curry((country, person) => person.birthCountry === country)
wasBornInCountry('GB') //=> [Function]
wasBornInCountry('GB', {birthCountry: 'GB'}) //=> true
wasBornInCountry('GB')({birthCountry: 'GB'}) //=> true
wasBornInCountry('GB')({birthCountry: 'IE'}) //=> false
var wasNaturalized = person => Boolean(person.naturalizationDate)
wasNaturalized({birthCountry: 'IE', naturalizationDate: '2014-01-01'}) //=> true
wasNaturalized({}) //=> false
var isOver18 = person => person.age >= 18
isOver18({age: 17}) //=> false
isOver18({age: 18}) //=> true
isOver18({age: 19}) //=> true
var isCitizen = R.curry((country, person) => R.either(wasBornInCountry(country), wasNaturalized)(person))
isCitizen('GB')({birthCountry: 'IE', naturalizationDate: '2014-01-01'})
isCitizen('GB', {birthCountry: 'IE', naturalizationDate: '2014-01-01'})
isCitizen('GB', {birthCountry: 'GB'})
var isEligibleToVote = (country, person) => R.both(isCitizen(country), isOver18)(person)
isEligibleToVote('GB', {birthCountry: 'GB', age: 19}) //=> true
isEligibleToVote('GB', {birthCountry: 'GB', age: 17}) //=> false
isEligibleToVote('GB', {birthCountry: 'IE', age: 19}) //=> false
isEligibleToVote('GB', {birthCountry: 'IE', age: 19, naturalizationDate: '2014-01-01'}) //=> true
var isEligibleToVoteGB = R.curry(isEligibleToVote)('GB');
isEligibleToVote('GB', {birthCountry: 'GB', age: 19}) //=> true
isEligibleToVoteGB({birthCountry: 'IE', age: 19}) //=> false
isEligibleToVoteGB({birthCountry: 'IE', age: 19, naturalizationDate: '2014-01-01'}) //=> true
var gt10 = x => x > 10;
var even = x => x % 2 === 0;
var f = R.either(gt10, even);
f(101); //=> true
f(8); //=> true
f(7) //=> false
// Define a curried greater than function
var gt = R.curry((x, n) => n > x);
gt(10, 11) //=> true
gt(10, 10) //=> false
gt(10, 9) //=> false
// Redefine the greater than 10 function by only supplying the first argument
// to our curried greater than function which will return a new function which
// accepts a single argument (the number to test)
var gt10 = gt(10)
gt10
var f2 = R.either(gt10, even);
f2(101); //=> true
f2(8) //=> true
f2(7) //=> false
var f3 = R.both(gt10, even);
f3(101); //=> false
f3(8) //=> false
f3(7) //=> false
f3(102); //=> true
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