RosettaCodeData/Task/Semordnilap/JavaScript/semordnilap-3.js

61 lines
1.4 KiB
JavaScript

(() => {
'use strict';
// semordnilap :: [String] -> String
const semordnilap = xs => {
const go = ([s, ws], w) =>
s.has(w.split('').reverse().join('')) ? (
[s, [w].concat(ws)]
) : [s.add(w), ws];
return xs.reduce(go, [new Set(), []])[1];
};
const main = () => {
// xs :: [String]
const xs = semordnilap(
lines(readFile('unixdict.txt'))
);
console.log(xs.length);
xs.filter(x => 4 < x.length).forEach(
x => showLog(...[x, x.split('').reverse().join('')])
)
};
// GENERIC FUNCTIONS ----------------------------
// lines :: String -> [String]
const lines = s => s.split(/[\r\n]/);
// readFile :: FilePath -> IO String
const readFile = fp => {
const
e = $(),
uw = ObjC.unwrap,
s = uw(
$.NSString.stringWithContentsOfFileEncodingError(
$(fp)
.stringByStandardizingPath,
$.NSUTF8StringEncoding,
e
)
);
return undefined !== s ? (
s
) : uw(e.localizedDescription);
};
// showLog :: a -> IO ()
const showLog = (...args) =>
console.log(
args
.map(JSON.stringify)
.join(' -> ')
);
// MAIN ---
return main();
})();