Difference between revisions of "DIP67"
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== Usage == | == Usage == | ||
<syntaxhighlight lang="d"> | <syntaxhighlight lang="d"> | ||
| + | import std.range; | ||
struct AssociativeRange | struct AssociativeRange | ||
{ | { | ||
| Line 60: | Line 61: | ||
</syntaxhighlight> | </syntaxhighlight> | ||
<syntaxhighlight lang="d"> | <syntaxhighlight lang="d"> | ||
| + | import std.range; | ||
struct LazyAssociativeRange | struct LazyAssociativeRange | ||
{ | { | ||
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alias V=ElementValueType!LazyAssociativeRange; | alias V=ElementValueType!LazyAssociativeRange; | ||
</syntaxhighlight> | </syntaxhighlight> | ||
| + | |||
== Copyright == | == Copyright == | ||
This document has been placed in the Public Domain. | This document has been placed in the Public Domain. | ||
[[Category: DIP]] | [[Category: DIP]] | ||
Revision as of 22:49, 28 October 2014
| Title: | Associative Ranges |
|---|---|
| DIP: | 67 |
| Version: | 1 |
| Status: | Draft |
| Created: | 2014-10-28 |
| Last Modified: | 2014-10-28 |
| Author: | Freddy "superstar64" Cubas |
| Links: |
Contents
Abstract
Introduce Associative ranges and lazy associative ranges to phobos. A associative range is a user defined container that has all the features of a build-in associative array. A lazy associative range is a sub set of a associative with only a index operator(of any type)
Rationale
Allow abtraction of hashmaps with ranges.
Description
An associative range must have: A byKey attribute that returns an input range of keys, A byValue attribute that returns an input range of values, byKey and byValue must be align to the same Pair when iterating. An index operator that takes a key and returns a value. An in operator that takes a key and returns a value pointer(or a user defined type that acts like one) or null if it doesn't exist.
A lazy associative range must have: An alias to the key type "KeyType" An alias to the value type "ValueType" An index operator that takes a key type and returns value.
Usage
import std.range;
struct AssociativeRange
{
float[] byKey;
uint[] byValue;
uint opIndex(float);
const (uint)* opBinaryRight(string op)(float) if(op=="in");
}
static assert(isAssociativeRange!AssociativeRange);
alias K=ElementKeyType!AssociativeRange;
alias V=ElementValueType!AssociativeRange;
import std.range;
struct LazyAssociativeRange
{
alias KeyType=double;
alias ValueType=float;
float opIndex(double);
}
static assert(isLazyAssociativeRange!LazyAssociativeRange);
alias K=ElementKeyType!LazyAssociativeRange;
alias V=ElementValueType!LazyAssociativeRange;
Copyright
This document has been placed in the Public Domain.
