← Starting Henceforth
Episode 4
Words from words
Words made from words — all the way down to a payment.
1:53 · Vivaldi · Allegro (RV 297 i)
Watch here · code in the app
Henceforth is the real terminal — one purchase ($9.99) for iPhone, iPad and Mac. Type the commands below into the app as you watch.
Code along
Tap to copy, then type it into Henceforth.
What you’ll learn
- ✓ A colon definition teaches a new word: : double 2 * ; — then it's yours, used like any built-in.
- ✓ Bigger words are built from the small ones — quadruple is double double, square is dup *, cube is dup square *. Factoring, all the way down.
- ✓ Mistype a word and Henceforth points you home with a did you mean? hint — and a payment, : pay-rent … send ;, is defined the exact same way.
Transcript
- last time — small words made big maths.
- but where do the small words come from?
- you make them. watch.
- double. you taught it this — episode one.
- still here. yours, and built-in, all at once.
- and you can look inside. there's its recipe.
- now — a bigger word, from the one you made.
- quadruple. just double — twice.
- twenty. a word, standing on a word.
- what if a word needs its number twice?
- you copy the top. that's dup.
- dup copies it — then times itself.
- forty-nine. seven, squared.
- cube stands on square — square stands on dup.
- small words. all the way down.
- and a word you never taught it?
- no — it only knows the words you made.
- but see — it points you home.
- one more. remember this — from episode one?
- that bitcoin word? it was a word i defined.
- same colon. same semicolon. same : ... ;
- a payment is just another word you teach.
- henceforth.