The D Programming Language's Unofficial Docs
beta
The D Programming Language's Unofficial Docs
beta
An input range of input ranges to be joined.
A range of elements in the joined range. This will be a forward range if both outer and inner ranges of RoR are forward ranges; otherwise it will be only an input range. The range bidirectionality is propagated if no separator is specified.
import std.algorithm.comparison : equal; import std.conv : text; assert(["abc", "def"].joiner.equal("abcdef")); assert(["Mary", "has", "a", "little", "lamb"] .joiner("...") .equal("Mary...has...a...little...lamb")); assert(["", "abc"].joiner("xyz").equal("xyzabc")); assert([""].joiner("xyz").equal("")); assert(["", ""].joiner("xyz").equal("xyz"));
import std.algorithm.comparison : equal; import std.range : repeat; assert([""].joiner.equal("")); assert(["", ""].joiner.equal("")); assert(["", "abc"].joiner.equal("abc")); assert(["abc", ""].joiner.equal("abc")); assert(["abc", "def"].joiner.equal("abcdef")); assert(["Mary", "has", "a", "little", "lamb"].joiner.equal("Maryhasalittlelamb")); assert("abc".repeat(3).joiner.equal("abcabcabc"));
joiner allows in-place mutation!
import std.algorithm.comparison : equal; auto a = [ [1, 2, 3], [42, 43] ]; auto j = joiner(a); j.front = 44; assert(a == [ [44, 2, 3], [42, 43] ]); assert(equal(j, [44, 2, 3, 42, 43]));
insert characters fully lazily into a string
import std.algorithm.comparison : equal; import std.range : chain, cycle, iota, only, retro, take, zip; import std.format : format; static immutable number = "12345678"; static immutable delimiter = ","; auto formatted = number.retro .zip(3.iota.cycle.take(number.length)) .map!(z => chain(z[0].only, z[1] == 2 ? delimiter : null)) .joiner .retro; static immutable expected = "12,345,678"; assert(formatted.equal(expected));
joiner can be bidirectional
import std.algorithm.comparison : equal; import std.range : retro; auto a = [[1, 2, 3], [4, 5]]; auto j = a.joiner; j.back = 44; assert(a == [[1, 2, 3], [4, 44]]); assert(equal(j.retro, [44, 4, 3, 2, 1]));
std.range.chain, which chains a sequence of ranges with compatible elements into a single range.
Lazily joins a range of ranges with a separator. The separator itself is a range. If a separator is not provided, then the ranges are joined directly without anything in between them (often called flatten in other languages).