Standard library¶

The RCL standard library is a dict of values that is in scope by default under the name std. Most of the built-in functionality is not in this std dict, but in methods on the builtin types. See the next chapters for those.

empty_set¶

std.empty_set: Set[Void]

An empty set. This constant exists, because without type annotations, {} is an empty dict rather than an empty set. This constant is the standard way to refer to an empty set.

range¶

std.range: (lower: Int, upper: Int) -> List[Int]

Return the range of integers lower through upper. The lower bound is inclusive and the upper bound is exclusive. When the lower bound is greater than the upper bound, range returns an empty list.

std.range(3, 7)
// Evaluates to:
[3, 4, 5, 6]

std.range(7, 3)
// Evaluates to:
[]

read_file_utf8¶

std.read_file_utf8: (path: String) -> String

Return the contents of the file at the given path. Paths are treated the same as for imports, and are subject to the same sandbox restrictions. The file must contain valid UTF-8 text without byte order mark.