fabric-carpet/docs/scarpet/language/VariablesAndConstants.md

Variables and Constants

scarpet provides a number of constants that can be used literally in scripts

• null: nothing, zilch, not even false
• true: pure true, or just 1 (one)
• false: false truth, or true falsth, 0 (zero) actually
• pi: for the fans of perimeters, its a perimeter of an apple pi of diameter 1. About 3.14
• euler: clever guy. Derivative of its exponent is goto 1. About 2.72

Apart from that, there is a bunch of system variables, that start with _ that are set by scarpet built-ins, like _, typically each consecutive value in loops, _i indicating iteration, or _a like an accumulator for reduce function. Certain calls to Minecraft specific calls would also set _x, _y, _z, indicating block positions. All variables starting with _ are read-only, and cannot be declared and modified in client code.

Literals

scarpet accepts numeric and string liters constants. Numbers look like 1, 2.5, -3e-7, 0xff, and are internally represented primarily as Java's double but scarpet will try to trim trailing zeros as much as possible so if you need to use them as integers or even longs - you can. However any operation on a number even if it can be properly represented as long, but not a double type, will make them round up to be doubles.

Strings use single quoting, for multiple reasons, but primarily to allow for easier use of strings inside doubly quoted command arguments (when passing a script as a parameter of /script fill for example), or when typing in jsons inside scarpet (to feed back into a /data merge command for example). Strings also use backslashes \ for quoting special characters, in both plain strings and regular expressions

'foo'
print('This doesn\'t work')
nbt ~ '\\.foo'   // matching '.' as a '.', not 'any character match'