block

A group of adjacent lines that are indented the same amount, further than the previous, controlling line.

co

The official file extension.

exist

To be defined and not null.

dedent

To close a block by indenting fewer on the following line.

implicit block

An inline block generated when an expression immediately follows ->, try etc.

implicit call

The syntax that allows you to write f x instead of f(x).

outdent

→ dedent

soak

To guard against non-existent or non-callable values by transforming into an if expression. E.g.:

• o?.p → o.p if o?
• f? x → f x if typeof f == 'function'

splat

To expand with ..., or the operator itself. The symbol used to be the actual splat (* from Ruby), later changed but the name stuck. We don't call it spread/rest a la ES6 as it does more, working also on non-trailing positions ((...a, b) ->).

then

A mysteriously undocumented keyword that explicitly creates an implicit block.