infix :
Documentation for infix :
assembled from the following types:
language documentation Operators
From Operators
(Operators) infix :
Used as an argument separator just like infix ,
and marks the argument to its left as the invocant. That turns what would otherwise be a function call into a method call.
substr('abc': 1); # same as 'abc'.substr(1)
Infix :
is only allowed after the first argument of a non-method call. In other positions, it's a syntax error.