<list> Class Reference

Methods in this pseudo-class can be executed on lists. More...

#include <Pseudo_QC_List.dox.h>

Inheritance diagram for Qore::<list>:

Public Member Methods
bool	complexType ()
	returns True if the list has a Hash With Declared Value Type, False if not More...
bool	contains (auto arg)
	Returns True if the list contains arg, False if it does not. More...
bool	empty ()
	Returns True if the list is empty (size = 0), False if not. More...
auto	first ()
	Returns the first entry in the list. More...
AbstractIterator	iterator ()
	Returns a ListIterator object for the list. More...
string	join (string str)
	Creates a string from the list and a separator string given as an argument. More...
auto	last ()
	Returns the last entry in the list. More...
int	lsize ()
	Returns the number of elements in the list. More...
AbstractIterator	rangeIterator (auto val)
	Returns a RangeIterator object for the list elements. More...
int	size ()
	Returns the number of elements in the list. More...
bool	sizep ()
	Returns True since lists can return a non-zero size. More...
int	typeCode ()
	Returns Qore::NT_LIST. More...
bool	val ()
	Returns False if the list is empty (size = 0), True if not. More...
Public Member Methods inherited from <value>
bool	callp ()
	Returns False; this method is reimplemented in other types and will return True if the given expression is a callable value (ie closures or call references) More...
bool	complexType ()
	returns True if the value has a complex type, False if not More...
bool	empty ()
	Returns True; this method will be reimplemented in container types where it may return False. More...
string	fullType (*bool with_namespaces)
	returns the full type name which differs from the simple type name in case of complex types and objects More...
bool	intp ()
	Returns False; this method is reimplemented in other types and will return True if the given expression can be converted to an integer. More...
AbstractIterator	iterator ()
	Returns an iterator object for the value; the default iterator object returned is SingleValueIterator. More...
int	lsize ()
	Returns 1; the return value of this method should give the list size of the value, which is normally 1 for non-lists (except for NOTHING where the size will be 0) and the number of the elements in the list for lists; this method will be reimplemented in other types where it may return other values. More...
int	size ()
	Returns zero; this method will be reimplemented in container types where it may return a non-zero value. More...
bool	sizep ()
	Returns True if the type can return a non-zero size (True for containers including binary objects and strings, False for everything else) More...
bool	strp ()
	Returns False; this method is reimplemented in other types and will return True if the given expression can be converted to a string. More...
bool	toBool ()
	Returns the boolean representation of the value; the default is False. More...
float	toFloat ()
	Returns the floating-point representation of the value; the default is 0.0. More...
int	toInt ()
	Returns the integer representation of the value; the default is 0. More...
number	toNumber ()
	Returns the arbitrary-precision numeric representation of the value; the default is 0. More...
string	toString ()
	Returns the string representation of the value; the default is an empty string. More...
string	type ()
	Returns the string type for the value. More...
int	typeCode ()
	Returns the type code for the value. More...
bool	val ()
	Returns False; this method is reimplemented in other types and will return True if the given expression has a non-empty value. More...

Detailed Description

Methods in this pseudo-class can be executed on lists.

Member Function Documentation

complexType()

bool <list>::complexType

(

)

returns True if the list has a Hash With Declared Value Type, False if not

Code Flags:

CONSTANT

Example:

bool b = n.complexType();

Returns

True if the list has a Hash With Declared Value Type, False if not

See also

• <value>::fullType()

Since

Qore 0.8.13

contains()

bool <list>::contains

(

auto

arg

)

Returns True if the list contains arg, False if it does not.

This call uses "soft" comparisons (where types may be converted). The computational complexity is O(n) (n = the length of the list).

Code Flags:

RET_VALUE_ONLY

Parameters

arg	any value to check its presence in the list

Returns

True if the list contains arg, False if it does not

Example:

list<int> l = (1, 2, 3);
bool b = l.contains(5); # returns False

empty()

bool <list>::empty

(

)

Returns True if the list is empty (size = 0), False if not.

The opposite of <list>::val()

Returns

True if the list is empty (size = 0), False if not

Code Flags:

CONSTANT

Example:

bool b = l.empty();

first()

auto <list>::first

(

)

Returns the first entry in the list.

Returns

the first entry in the list

Code Flags:

CONSTANT

Example:

auto e = l.first();

See also

<list>::last()

Since

Qore 0.8.5

iterator()

AbstractIterator <list>::iterator

(

)

Returns a ListIterator object for the list.

Returns

a ListIterator object for the list

Code Flags:

CONSTANT

Example:

map printf("+ %y\n", $1), l.iterator();

Since

Qore 0.8.6

join()

string <list>::join

(

string

str

)

Creates a string from the list and a separator string given as an argument.

Each element in the list will be converted to a string if necessary to be concatenated to the return value string; additionally if any string argument has a different character encoding than str, then it will be converted to str's character encoding before concatentation to the return value string

Code Flags:

RET_VALUE_ONLY

Parameters

str	the separator string

Returns

a string created from a list and a separator string, each element in the list will be present in the return value separated by the separator string; the string returned with have the same character encoding as str

Example:

string str = ("a", "b", "c").join(":"); # returns "a:b:c"

Exceptions

ENCODING-CONVERSION-ERROR

this exception could be thrown if the string arguments have different character encodings and an error occurs during encoding conversion

Note

equivalent to join(string, list)

Since

Qore 0.8.5

last()

auto <list>::last

(

)

Returns the last entry in the list.

Returns

the last entry in the list

Code Flags:

CONSTANT

Example:

auto e = l.last();

See also

<list>::first()

Since

Qore 0.8.5

lsize()

int <list>::lsize

(

)

Returns the number of elements in the list.

For this type, this method is equivalent to size()

Returns

the number of elements in the list

Code Flags:

CONSTANT

Example:

printf("iterating %d element%s\n", val.lsize(), val.lsize() == 1 ? "" : "s");
foreach auto element in (val) {
    do_something(element);
}

rangeIterator()

AbstractIterator <list>::rangeIterator

(

auto

val

)

Returns a RangeIterator object for the list elements.

Code Flags:

CONSTANT

Example:

map printf("+ %y\n", $1), l.ranegIterator();

Parameters

val	an optional value to be returned instead of the default integer value

Returns

a RangeIterator object for the list elements

Since

• Qore 0.8.8
• Qore 0.8.11.1 this pseudo-method takes the optional val argument

size()

int <list>::size

(

)

Returns the number of elements in the list.

Returns

the number of elements in the list

Code Flags:

CONSTANT

Example:

int len = l.size();

See also

<list>::sizep()

sizep()

bool <list>::sizep

(

)

Returns True since lists can return a non-zero size.

Code Flags:

CONSTANT

Returns

True since lists can return a non-zero size

See also

<list>::size()

Since

Qore 0.8.9

typeCode()

int <list>::typeCode

(

)

Returns Qore::NT_LIST.

Returns

Qore::NT_LIST

Code Flags:

CONSTANT

Example:

switch (l.typeCode()) {
    case NT_LIST:
        printf("%y: is a list\n", l);
        break;
}

val()

bool <list>::val

(

)

Returns False if the list is empty (size = 0), True if not.

The opposite of <list>::empty()

Returns

False if the list is empty (size = 0), True if not

Code Flags:

CONSTANT

Example:

bool b = l.val();

See also

• %perl-bool-eval
• %strict-bool-eval