Perl 6 Documentationroutine pred
Documentation for routine pred assembled from the following types:
class Numeric
From Numeric
(Numeric) method pred
method pred(Numeric:)
Returns the number decremented by one (predecessor).
enum Bool
From Bool
(Bool) routine pred
method pred(--> Bool)
Returns False.
say True.pred; # OUTPUT: «False»say False.pred; # OUTPUT: «False»
pred is short for "predecessor"; it returns the previous enum value. Bool is a special enum with only two values, False and True. When sorted, False comes first, so False is the predecessor to True. And since False is the "lowest" Bool enum value, its own predecessor is also False.
role Enumeration
From Enumeration
(Enumeration) method pred
Defined as:
method pred(::?CLASS:)
say Freija.pred; # OUTPUT: «Oðin»
class Date
From Date
(Date) method pred
Defined as:
method pred(Date: --> Date)
Returns a Date of the previous day. "pred" is short for "predecessor".
say Date.new("2016-01-01").pred; # OUTPUT: «2015-12-31»
class Str
From Str
(Str) method pred
method pred(Str: --> Str)
Returns the string decremented by one.
String decrementing is "magical" just like string increment (see succ). It fails on underflow
'b0'.pred; # RESULT: «a9»'a0'.pred; # Failure'img002.png'.pred; # RESULT: «img001.png»
class IO::Path
From IO::Path
(IO::Path) method pred
Defined as:
method pred(IO::Path: --> IO::Path)
Returns a new IO::Path constructed from the invocant, with .basename changed by calling Str.pred on it.
"foo/file02.txt".IO.pred.say; # OUTPUT: «"foo/file01.txt".IO»