pipeline.js

const append = (text) => (value) => value + text;
const removeTheLetter = (letter) => (sentence) => 
    sentence
    .split('')
    .filter(c => c !== letter)
    .join('');

const makeLetterUpperCase = (letter) => (sentence) => 
    sentence.split('')
    .map(c => c === letter ? c.toUpperCase() : c)
    .join('');

const removeWordsWithLessThanFourLetters = (sentence) =>
    sentence
    .split(' ')
    .filter(word => word.length > 4)
    .join(' ');

const phrase = 'Welcome';
const result = removeWordsWithLessThanFourLetters(
    makeLetterUpperCase('e')(
        makeLetterUpperCase('a')(
            makeLetterUpperCase('o')(
                removeTheLetter('i')(
                    append(' pipelining')(
                        append(' I hope you like')(
                            append(' Functional Programming')(
                                append(' to')(phrase)
                            )
                        )
                    )
                )
            )
        )
    )
);

console.log(result);
// prints: WElcOmE FunctOnAl PrOgrAmmng ppElnng