Implement string slice assignments

This commit is contained in:
Eugen Wissner 2017-05-04 23:17:50 +02:00
parent db12f03264
commit a6a6f496eb

View File

@ -252,7 +252,7 @@ struct ByCodePoint(E)
return this.begin == this.end;
}
@property dchar front() const
@property dchar front() const @trusted
in
{
assert(!empty);
@ -264,55 +264,60 @@ struct ByCodePoint(E)
body
{
dchar chr;
ubyte units;
char mask;
const(char)* it = begin;
ubyte units, mask;
const(char)* it = this.begin;
if (*it & 0x80)
{
mask = 0xe0;
for (units = 1; (*it & mask) != (mask << 1); ++units)
for (units = 2; ((*it << units) & 0x80) != 0; ++units)
{
mask = (mask >> 1) | 0x80;
}
}
chr = *it++ ^ mask;
for (; units > 0; --units)
if (this.begin + units > end || units > 4)
{
throw defaultAllocator.make!UTFException("Invalid UTF-8 character");
}
chr = *it++ & ~mask;
for (; units > 1; --units)
{
if (begin >= end)
{
throw defaultAllocator.make!UTFException("Invalid UTF-8 character");
}
chr = (chr << 6) | (*it++ & 0x3f);
}
return chr;
}
void popFront()
void popFront() @trusted
in
{
assert(!empty);
}
body
{
if (*begin & 0x80)
ubyte units;
if ((*begin & 0x80) == 0)
{
char mask = 0xe0;
for (auto chr = *begin; (chr & mask) != (mask << 1); ++begin)
{
if (begin >= end)
{
throw defaultAllocator.make!UTFException("Invalid UTF-8 character");
}
mask = (mask >> 1) | 0x80;
}
units = 1;
}
else
else if ((*begin & 0xc0) == 0xc0)
{
++begin;
units = 2;
}
else if ((*begin & 0xe0) == 0xe0)
{
units = 3;
}
else if ((*begin & 0xf0) == 0xf0)
{
units = 4;
}
if (units == 0 || this.begin + units > this.end)
{
throw defaultAllocator.make!UTFException("Invalid UTF-8 character");
}
this.begin += units;
}
ByCodePoint opIndex()
@ -865,6 +870,68 @@ struct String
assert(s.capacity == 38);
}
/**
* Slicing assignment.
*
* Params:
* R = Type of the assigned slice.
* value = New value (single value, range or string).
* i = Slice start.
* j = Slice end.
*
* Returns: Slice with the assigned part of the string.
*
* Precondition: $(D_INLINECODE i <= j && j <= length
* && value.length == j - i)
*/
ByCodeUnit!char opSliceAssign(R)(ByCodeUnit!R value,
const size_t i,
const size_t j) @trusted
if (is(Unqual!R == char))
in
{
assert(i <= j);
assert(j <= length);
assert(j - i == value.length);
}
body
{
copy(value, this.data[i .. j]);
return opSlice(i, j);
}
/// Ditto.
ByCodeUnit!char opSliceAssign(const char[] value,
const size_t i,
const size_t j)
pure nothrow @trusted @nogc
in
{
assert(i <= j);
assert(j <= length);
}
body
{
copy(value[], this.data[i .. j]);
return opSlice(i, j);
}
/// Ditto.
ByCodeUnit!char opSliceAssign(const char value,
const size_t i,
const size_t j)
pure nothrow @trusted @nogc
in
{
assert(i <= j);
assert(j <= length);
}
body
{
fill(this.data[i .. j], value);
return opSlice(i, j);
}
/**
* Returns an array used internally by the string.
* The length of the returned array may be smaller than the size of the
@ -970,8 +1037,30 @@ struct String
return typeof(return)(this, this.data, this.data + length);
}
///
@safe @nogc unittest
{
auto s = String("Высоцкий");
auto cp = s.byCodePoint();
assert(cp.front == 'В');
cp.popFront();
assert(cp.front == 'ы');
cp.popFront();
assert(cp.front == 'с');
s = String("€");
cp = s.byCodePoint();
assert(cp.front == '€');
assert(s.length == 3);
s = String("\U00024B62");
cp = s.byCodePoint();
assert(cp.front == '\U00024B62');
assert(s.length == 4);
}
/**
* Returns: $(D_KEYWORD true) if the vector is empty.
* Returns: $(D_KEYWORD true) if the string is empty.
*/
@property bool empty() const pure nothrow @safe @nogc
{
@ -1068,7 +1157,7 @@ struct String
}
/// Ditto.
ref String opAssig(S)(ref S that) @trusted
ref String opAssign(S)(ref S that) @trusted
if (is(Unqual!S == String))
{
reserve(that.length);
@ -1219,5 +1308,51 @@ struct String
assert(s == "У меня на сердце");
}
/**
* Assigns a value to the character with the index $(D_PARAM pos).
*
* Params:
* value = Value.
* pos = Position.
*
* Returns: Assigned value.
*
* Precondition: $(D_INLINECODE length > pos).
*/
ref char opIndexAssign(const char value, const size_t pos)
pure nothrow @safe @nogc
{
return opIndex(pos) = value;
}
/**
* Assigns a range or a string.
*
* Params:
* R = Value type.
* value = Value.
*
* Returns: Assigned value.
*
* Precondition: $(D_INLINECODE length == value.length).
*/
ByCodeUnit!char opIndexAssign(R)(ByCodeUnit!R value)
if (is(Unqual!R == char))
{
return opSliceAssign(value, 0, length);
}
/// Ditto.
ByCodeUnit!char opIndexAssign(const char value) pure nothrow @safe @nogc
{
return opSliceAssign(value, 0, length);
}
/// Ditto.
ByCodeUnit!char opIndexAssign(const char[] value) pure nothrow @safe @nogc
{
return opSliceAssign(value, 0, length);
}
mixin DefaultAllocator;
}