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Move single-element predicate-only find above subrange find

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This commit is contained in:
Nick Treleaven 2014-12-01 17:24:43 +00:00
parent c1c923e8ed
commit 038d2f1054
1 changed files with 78 additions and 78 deletions
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156
std/algorithm.d
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@ -5296,6 +5296,84 @@ if (isInputRange!InputRange &&
assert([x].find(x).empty == false);
}
/**
Advances the input range $(D haystack) by calling $(D haystack.popFront)
until either $(D pred(haystack.front)), or $(D
haystack.empty). Performs $(BIGOH haystack.length) evaluations of $(D
pred).
To find the last element of a bidirectional $(D haystack) satisfying
$(D pred), call $(D find!(pred)(retro(haystack))). See $(XREF
range, retro).
See_Also:
$(WEB sgi.com/tech/stl/find_if.html, STL's find_if)
*/
InputRange find(alias pred, InputRange)(InputRange haystack)
if (isInputRange!InputRange)
{
alias R = InputRange;
alias predFun = unaryFun!pred;
static if (isNarrowString!R)
{
import std.utf : decode;
immutable len = haystack.length;
size_t i = 0, next = 0;
while (next < len)
{
if (predFun(decode(haystack, next)))
return haystack[i .. $];
i = next;
}
return haystack[$ .. $];
}
else static if (!isInfinite!R && hasSlicing!R && is(typeof(haystack[cast(size_t)0 .. $])))
{
size_t i = 0;
foreach (ref e; haystack)
{
if (predFun(e))
return haystack[i .. $];
++i;
}
return haystack[$ .. $];
}
else
{
//standard range
for ( ; !haystack.empty; haystack.popFront() )
{
if (predFun(haystack.front))
break;
}
return haystack;
}
}
///
@safe unittest
{
auto arr = [ 1, 2, 3, 4, 1 ];
assert(find!("a > 2")(arr) == [ 3, 4, 1 ]);
// with predicate alias
bool pred(int x) { return x + 1 > 1.5; }
assert(find!(pred)(arr) == arr);
}
@safe pure unittest
{
//scope(success) writeln("unittest @", __FILE__, ":", __LINE__, " done.");
int[] r = [ 1, 2, 3 ];
assert(find!(a=>a > 2)(r) == [3]);
bool pred(int x) { return x + 1 > 1.5; }
assert(find!(pred)(r) == r);
assert(find!(a=>a > 'v')("hello world") == "world");
assert(find!(a=>a%4 == 0)("日本語") == "本語");
}
/**
Finds a forward range in another. Elements are compared for
equality. Performs $(BIGOH walkLength(haystack) * walkLength(needle))
@ -5909,84 +5987,6 @@ Range1 find(Range1, alias pred, Range2)(
assert(match.empty);
}
/**
Advances the input range $(D haystack) by calling $(D haystack.popFront)
until either $(D pred(haystack.front)), or $(D
haystack.empty). Performs $(BIGOH haystack.length) evaluations of $(D
pred).
To find the last element of a bidirectional $(D haystack) satisfying
$(D pred), call $(D find!(pred)(retro(haystack))). See $(XREF
range, retro).
See_Also:
$(WEB sgi.com/tech/stl/find_if.html, STL's find_if)
*/
InputRange find(alias pred, InputRange)(InputRange haystack)
if (isInputRange!InputRange)
{
alias R = InputRange;
alias predFun = unaryFun!pred;
static if (isNarrowString!R)
{
import std.utf : decode;
immutable len = haystack.length;
size_t i = 0, next = 0;
while (next < len)
{
if (predFun(decode(haystack, next)))
return haystack[i .. $];
i = next;
}
return haystack[$ .. $];
}
else static if (!isInfinite!R && hasSlicing!R && is(typeof(haystack[cast(size_t)0 .. $])))
{
size_t i = 0;
foreach (ref e; haystack)
{
if (predFun(e))
return haystack[i .. $];
++i;
}
return haystack[$ .. $];
}
else
{
//standard range
for ( ; !haystack.empty; haystack.popFront() )
{
if (predFun(haystack.front))
break;
}
return haystack;
}
}
///
@safe unittest
{
auto arr = [ 1, 2, 3, 4, 1 ];
assert(find!("a > 2")(arr) == [ 3, 4, 1 ]);
// with predicate alias
bool pred(int x) { return x + 1 > 1.5; }
assert(find!(pred)(arr) == arr);
}
@safe pure unittest
{
//scope(success) writeln("unittest @", __FILE__, ":", __LINE__, " done.");
int[] r = [ 1, 2, 3 ];
assert(find!(a=>a > 2)(r) == [3]);
bool pred(int x) { return x + 1 > 1.5; }
assert(find!(pred)(r) == r);
assert(find!(a=>a > 'v')("hello world") == "world");
assert(find!(a=>a%4 == 0)("日本語") == "本語");
}
// findSkip
/**
* If $(D needle) occurs in $(D haystack), positions $(D haystack)