. Skeleton
infix .
.The rules for . have not been written yet. Everything below is extracted rather than authored: the official documentation supplies the classification, and the interpreters were asked directly about the rest.
What is established #
Classification #
. is parsed as an infix at the dotty infix precedence level, left-associative.
That is level 6 of 27 on the ladder, counting from the tightest. Operators sharing a level bind equally; grouping among them is decided by associativity alone.
Shares its precedence level with #
.=.
These all bind equally tightly, so an expression mixing them groups by associativity alone.
What the interpreter said #
Raku++ parses this spelling. Asked to compile:
my $a = 6; my $b = 3; sink($a . $b)
…it got through the parser. On its own that establishes very little: it says nothing about whether the construct executes, let alone whether the result is right. Where the behaviour table below exists, that is the stronger evidence — those expressions were actually run.
Covered upstream #
The official documentation has a section for this construct: docs.raku.org. Until the rules here are written, that is the better reference.
Observed behaviour #
Each expression below was executed by both interpreters when this page was built; the results are recorded, not written. The operands are chosen to cross the boundaries that catch people out: string against number, a list where a scalar was meant, a boolean, an undefined value, and an exact rational.
Raku++ and Rakudo agree on every row below.
| Expression | Raku++ | Rakudo |
|---|---|---|
1 . 2 | rejected by both — Parse error | |
"a" . "b" | rejected by both — Parse error | |
1 . "2" | rejected by both — Parse error | |
(1, 2) . (3, 4, 5) | rejected by both — Cannot invoke non-Callable value of type List | |
True . False | rejected by both — No such method 'False' for invocant of type 'Bool' | |
Nil . 1 | rejected by both — Parse error | |
1/2 . 1/3 | rejected by both — Parse error | |