Raku Documentation
routine Bool
Documentation for routine Bool assembled from the following types:
class NumStr
From NumStr
(NumStr) method Bool
Defined as:
multi method Bool(NumStr:D: --> Bool:D)
This method may be provided by the parent classes and not implemented in NumStr directly.
Returns False if the invocant is numerically ±0e0, otherwise returns True. String portion is not considered.
class ComplexStr
From ComplexStr
(ComplexStr) method Bool
Defined as:
multi method Bool(ComplexStr:D: --> Bool:D)
This method may be provided by the parent classes and not implemented in ComplexStr directly.
Returns False if the invocant is numerically ±0±0i, otherwise returns True. String portion is not considered.
role Setty
From Setty
(Setty) method Bool
Defined as:
multi method Bool(Setty:D: --> Bool:D)
Returns True if the invocant contains at least one element.
my $s1 = Set.new(1, 2, 3); say $s1.Bool; # OUTPUT: «True» my $s2 = $s1 ∩ Set.new(4, 5); # set intersection operator say $s2.Bool; # OUTPUT: «False»
class Failure
From Failure
(Failure) method Bool
Defined as:
multi method Bool(Failure:D: --> Bool:D)
Returns False, and marks the failure as handled.
sub f() { fail }; my $v = f; say $v.handled; $v.Bool; say $v.handled;
# OUTPUT: «False
# True»
class RatStr
From RatStr
(RatStr) method Bool
Defined as:
multi method Bool(RatStr:D: --> Bool:D)
This method may be provided by the parent classes and not implemented in RatStr directly.
Returns False if the numerator of the numeric portion is 0, otherwise returns True. This applies for < 0/0 > zero-denominator RatStr as well, despite ?< 0/0 >.Num being True. String portion is not considered.
class Match
From Match
(Match) method Bool
Defined as:
method Bool(Capture:D: --> Bool:D)
Returns True on successful and False on unsuccessful matches. Please note that any zero-width match can also be successful.
say 'abc' ~~ /^/; # OUTPUT: «｢｣» say $/.from, ' ', $/.to, ' ', ?$/; # OUTPUT: «0 0 True»
class Str
From Str
(Str) method Bool
Defined as:
method Bool(Str:D: --> Bool:D)
Returns False if the string is empty, True otherwise.
class IntStr
From IntStr
(IntStr) method Bool
Defined as:
multi method Bool(IntStr:D: --> Bool:D)
This method may be provided by the parent classes and not implemented in IntStr directly.
Returns False if the invocant is numerically 0, otherwise returns True. String portion is not considered.
role Blob
From Blob
(Blob) method Bool
Defined as:
multi method Bool(Blob:D:)
Returns False if and only if the buffer is empty.
my $blob = Blob.new(); say $blob.Bool; # OUTPUT: «False» $blob = Blob.new([1, 2, 3]); say $blob.Bool; # OUTPUT: «True»
role Baggy
From Baggy
(Baggy) method Bool
Defined as:
method Bool(Baggy:D: --> Bool:D)
Returns True if the invocant contains at least one element.
my $breakfast = ('eggs' => 1).BagHash;
say $breakfast.Bool; # OUTPUT: «True (since we have one element)»
$breakfast<eggs> = 0; # weight == 0 will lead to element removal
say $breakfast.Bool; # OUTPUT: «False»
class Regex
From Regex
(Regex) method Bool
multi method Bool(Regex:D: --> Bool:D)
Matches against the caller's $_ variable, and returns True for a match or False for no match.
class Proc
From Proc
(Proc) method Bool
multi method Bool(Proc:D:)
Awaits for the process to finish and returns True if both exit code and signal of the process were 0, indicating a successful process termination. Returns False otherwise.
class Promise
From Promise
(Promise) method Bool
multi method Bool(Promise:D:)
Returns True for a kept or broken promise, and False for one in state Planned.
class Map
From Map
(Map) method Bool
Defined as:
method Bool(Map:D: --> Bool:D)
Returns True if the invocant contains at least one key/value pair.
my $m = Map.new('a' => 2, 'b' => 17);
say $m.Bool; # OUTPUT: «True»
class List
From List
(List) method Bool
Defined as:
method Bool(List:D: --> Bool:D)
Returns True if the list has at least one element, and False for the empty list.
say ().Bool; # OUTPUT: «False» say (1).Bool; # OUTPUT: «True»
class Numeric
From Numeric
(Numeric) method Bool
multi method Bool(Numeric:D:)
Returns False if the number is equivalent to zero, and True otherwise.
class Junction
From Junction
(Junction) method Bool
Defined as:
multi method Bool(Junction:D:)
Collapses the Junction and returns a single Boolean value according to the type and the values it holds. Every element is transformed to Bool.
my $n = Junction.new( "one", 1..6 ); say $n.Bool; # OUTPUT: «False»
All elements in this case are converted to True, so it's false to assert that only one of them is.
my $n = Junction.new( "one", <0 1> ); say $n.Bool; # OUTPUT: «True»
Just one of them is truish in this case, 1, so the coercion to Bool returns True.
role Rational
From Rational
(Rational) method Bool
Defined as:
multi method Bool(Rational:D: --> Bool:D)
Returns False if numerator is 0, otherwise returns True. This applies for <0/0> zero-denominator Rational as well, despite ?<0/0>.Num being True.
class StrDistance
From StrDistance
(StrDistance) method Bool
Returns True if before is different from after.
class Capture
From Capture
(Capture) method Bool
Defined as:
method Bool(Capture:D: --> Bool:D)
Returns True if the Capture contains at least one named or one positional argument.
say \(1,2,3, apples => 2).Bool; # OUTPUT: «True» say \().Bool; # OUTPUT: «False»
class Mu
From Mu
(Mu) routine Bool
multi sub Bool(Mu --> Bool:D) multi method Bool( --> Bool:D)
Returns False on the type object, and True otherwise.
Many built-in types override this to be False for empty collections, the empty string or numerical zeros
say Mu.Bool; # OUTPUT: «False»
say Mu.new.Bool; # OUTPUT: «True»
say [1, 2, 3].Bool; # OUTPUT: «True»
say [].Bool; # OUTPUT: «False»
say %( hash => 'full' ).Bool; # OUTPUT: «True»
say {}.Bool; # OUTPUT: «False»
say "".Bool; # OUTPUT: «False»
say 0.Bool; # OUTPUT: «False»
say 1.Bool; # OUTPUT: «True»
say "0".Bool; # OUTPUT: «True»