Terms
src
Most syntactic constructs in Perl 6 can be categorized in I<terms> and
L<operators|/language/operators>.
Here you can find an overview of different kinds of terms.
Literals
Int
42
12_300_00
:16<DEAD_BEEF>
L<Int> literals consist of digits, and can contain underscores
between any two digits.
To specify a base other than ten, use the colonpair form < :radix<number >>.
Rat
12.34
1_200.345_678
L<Rat> (rational numbers) literals contain two integer parts joined by a dot.
Note that trailing dots are not allowed, so you have to write 1.0 instead
of 1. (this rule is important because there are infix operators starting
with a dot, for example the .. L<Range> operator).
Num
12.3e-32
3e8
L<Num> (floating point numbers) literals consist of L<Rat> or L<Int> literals
followed by an e and a (possibly negative) exponent. 3e8 constructs a
L<Num> with value 3 * 10**8 .
Str
see the section on quoting constructs below.
Regex
see the section on quoting constructs below.
Pair
a => 1
'a' => 'b'
:identifier
:!identifier
:identifier<value>
:identifier<value1 value2>
:identifer($value)
:identifer['val1', 'val2']
:identifier{key1 => 'val1', key2 => 'value2'}
:$item
:@array
:%hash
:&callable
L<Pair> objects can be created either with < infix:«= » >> (which
auto-quotes the left-hand side if it is an identifier), or with the various
colonpair forms. Those always start with a colon, and then are followed either
by an identifier or the name of an already existing varible (whose name sans
the sigil is used as the key, and value of the variable is used as the value
of the pair).
In the identifier form a colonpair, the optional value can be any circumfix.
If it is left blank, the value is Bool::True . The value of the
:!identifier form is Bool::False .
If used in an argument list, all of these forms count as named arguments, with
the exception of < 'quoted string' = $value >>.
Parcel
()
1, 2, 3
<a b c>
«a b c»
qw/a b c/
L<Parcel> literals are: the empty pair of parens () , a comma-separated
list, or several quoting constructs
Quoting constructs
TODO
Identifier terms
There are built-in identifier terms in Perl 6, which are listed below.
In addition one can add new identifier terms with the syntax
sub term:<fourty-two> { 42 };
say fourty-two
or as constants
constant forty-two = 42;
say fourty-two
self
Inside a method, self refers to the invocant (i.e. the object the method
was called on). If used in a context where it doesn't make sense, a
compile-time exception of type L<X::Syntax::NoSelf> is thrown.
now
Returns an L<Instant> object representing the current time.
rand
Returns a pseudo-random L<Num> in the range 0..^1 .
pi
Returns the number pi , i.e. the ratio between circumference and diameter of
a circle.
e
Returns Euler's number
i
Returns the imaginary unit (for L<Complex> numbers).
Variables
Variables are discussed in L<variable language docs |/language/variables>.
