This example file aims to exercise most of snippin's features.

We can load snippets from the current directory:
#pin "s1" "A"

Or from a subdirectory:
#pin "d/s1" "A"

// Some prefixes are acceptable to the directive parser:
// #pin "s2" "A"
// while others aren't, e.g. #pin "s2" "A".

Pins to files that don't exist aren't loaded:
#pin "nonesuch" "A"

And neither are pins to snippets that don't exist:
#pin "s1" "nonesuch"

Pins are expanded without prefix, even if the line with the pin directive
is itself prefixed, e.g.

        // #pin "s1" "A"

And of course a file can contain more than one snippet:
#pin "s1" "B"