Engineer & Educator | Observable Ambassador | Karaoke Enthusiast
Functional JavaScript First StepsWhat is functional programming?Exercise: Pure FunctionsStaying out of the loop with recursionExercise: Iteration vs. RecursionFlying first class with higher-order functionsExercise: Filter, Map, ReduceGetting closureIt's functions all the way downExercise: Function CompositionImmutabilityExercise: Avoiding mutationRecap & takeawaysNext steps
Exercise: Closures & Currying
function writeMessage(message, salutation, name) {
return md`<p style="padding:3em;font-family:monospace">${message}<br><br>${salutation},<br>${name}</p>`;
}
writeMessage(
"You're doing amazing! Hopefully these exercises help you get a bit _closure_ to your programming goals.",
"Keep _currying_ on",
"Functional Pungrammer"
)
function signMessageFrom(name) {
return (message, salutation) => writeMessage(message, salutation, name);
}
writeFriendlyNote = signMessageFrom("Your best bud")
writeFriendlyNote("Hey pal! Party at my place tonight, bring snacks!", "See ya")
function signMessageWith(salutation) {
return () => {} // TODO replace this function
}
writeBusinessMemo = signMessageWith('Best')
writeBusinessMemo("Hi, Peter. We need to talk about your TPS reports.", "Bob")
function makeSignature(salutation, name) {
return () => {}; // TODO replace this function
}
writeLoveLetter = makeSignature("Thine evermore", "William")
writeLoveLetter(
"Shall I compare thee to a summer's day? Thou art more lovely and more temperate."
)
function quote(name, year, text) {
return md`<p style="font-size:smaller;padding:1em;font-family:monospace;">"${text}"<br>- ${name} (${year})</p>`;
}
grumpyQuotes = html`${[
quote(
'Guido van Rossum',
2001,
"Don't you hate code that's not properly indented?"
), // https://slashdot.org/story/01/04/20/1455252/guido-van-rossum-unleashed
quote(
'Doug Crockford',
2005,
'There are no good texts on JavaScript programming.'
), // http://crockford.com/javascript/style1.html
quote(
'Doug Crockford',
2008,
'JavaScript is an astonishing language, in the very worst sense.'
), // http://crockford.com/javascript/popular.html
quote(
'Edsger Dijkstra',
1978,
'Object oriented programming is an exceptionally bad idea which could only have originated in California.'
), // https://www.quora.com/Why-did-Dijkstra-say-that-%E2%80%9CObject-oriented-programming-is-an-exceptionally-bad-idea-which-could-only-have-originated-in-California-%E2%80%9D/answer/Terry-Moore-32
quote(
'Edsger Dijkstra',
1975,
'By claiming that they can contribute to software engineering, the soft scientists make themselves even more ridiculous.'
), // https://www.cs.utexas.edu/users/EWD/ewd04xx/EWD498.PDF
quote(
'Edsger Dijkstra',
1975,
"Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer."
) // ibid.
]}`
curriedQuote = () => {} // TODO replace this placeholder function
quoteCrockford = curriedQuote('Doug Crockford')
quoteDijkstra = curriedQuote('Edsger Dijkstra')
quoteDijkstra75 = quoteDijkstra(1975)
stillGrumpyQuotes = html`${[
curriedQuote('Guido van Rossum')(2001)(
"Don't you hate code that's not properly indented?"
),
quoteCrockford(2005)('There are no good texts on JavaScript programming.'),
quoteCrockford(2008)(
'JavaScript is an astonishing language, in the very worst sense.'
),
quoteDijkstra(1978)(
'Object oriented programming is an exceptionally bad idea which could only have originated in California.'
),
quoteDijkstra75(
'By claiming that they can contribute to software engineering, the soft scientists make themselves even more ridiculous.'
),
quoteDijkstra75(
"Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer."
),
quoteDijkstra75(
"The irony of my self-contradiction is lost on me. [Just kidding, he didn't actually say this one - making it all the more true!]"
)
]}`
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