Rules / Types, classes & roles / basic

Formatter Reference

Produce Callable for given format specification

What it is #

Routines #

Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.

method `new` #

method new($format --> Callable:D)

Returns Callable:D.

Returns a cached Callable object from a sprintf compatible format string. Will create a new Callable object if the given format string had not been seen before.

method `CODE` #

method CODE(--> Callable:D)

Returns Callable:D.

Returns an uncached Callable object from a sprintf compatible format string. Intended to be used in compile-time situations where caching is neither important nor wanted.

method `AST` #

method AST(--> RakuAST::Node:D)

Returns RakuAST::Node:D.

Returns a RakuAST representation of the Callable for the given sprintf compatible format string. Intended to be used for debugging.

Examples, run three ways #

Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.

1 no-output · 2 ok

class Formatter { }

Not executed: the documentation states no expected output for this example.

use v6.e.PREVIEW;
my &handle = Formatter.new("'%5s'");
say handle("foo");              # OUTPUT: «'  foo'␤»

Output

'  foo'

Documentation, Rakudo and Raku++ all agree.

use v6.e.PREVIEW;
my &zero5 = Formatter.new("%05d");
say zero5(42);                  # OUTPUT: «00042␤»