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| -rw-r--r-- | source/tanya/container/string.d | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/source/tanya/container/string.d b/source/tanya/container/string.d new file mode 100644 index 0000000..75298eb --- /dev/null +++ b/source/tanya/container/string.d @@ -0,0 +1,283 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/** + * UTF-8 string. + * + * Copyright: Eugene Wissner 2017. + * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/, + * Mozilla Public License, v. 2.0). + * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner) + */ +module tanya.container.string; + +import core.checkedint; +import core.exception; +import core.stdc.string; +import std.algorithm.comparison; +import tanya.memory; + +/** + * UTF-8 string. + */ +struct String +{ + private size_t length_; + private char* data; + private size_t capacity_; + + invariant + { + assert(length_ <= capacity_); + } + + /** + * Params: + * str = Initial string. + * allocator = Allocator. + */ + this(const(char)[] str, shared Allocator allocator = defaultAllocator) + nothrow @trusted @nogc + { + this(allocator); + reserve(str.length); + length_ = str.length; + memcpy(data, str.ptr, length_); + } + + /// Ditto. + this(const(wchar)[] str, shared Allocator allocator = defaultAllocator) + nothrow @trusted @nogc + { + this(allocator); + + bool overflow; + auto size = mulu(str.length, 4, overflow); + assert(!overflow); + + reserve(size); + + auto s = data; + auto sourceLength = str.length; + for (auto c = str.ptr; sourceLength != 0; ++c, --sourceLength) + { + if (*c < 0x80) + { + *s++ = *c & 0x7f; + length_ += 1; + } + else if (*c < 0x800) + { + *s++ = 0xc0 | (*c >> 6) & 0xff; + *s++ = 0x80 | (*c & 0x3f); + length_ += 2; + } + else if (*c < 0xd800 || *c - 0xe000 < 0x2000) + { + *s++ = 0xe0 | (*c >> 12) & 0xff; + *s++ = 0x80 | ((*c >> 6) & 0x3f); + *s++ = 0x80 | (*c & 0x3f); + length_ += 3; + } + else if ((*c - 0xd800) < 2048 && sourceLength > 0 && *(c + 1) - 0xdc00 < 0x400) + { // Surrogate pair + dchar d = (*c - 0xd800) | ((*c++ - 0xdc00) >> 10); + + *s++ = 0xf0 | (d >> 18); + *s++ = 0x80 | ((d >> 12) & 0x3f); + *s++ = 0x80 | ((d >> 6) & 0x3f); + *s++ = 0x80 | (d & 0x3f); + --sourceLength; + length_ += 4; + } + } + } + + /// + @safe @nogc unittest + { + auto s = String("\u10437"w); + assert("\u10437" == s.get()); + } + + /// Ditto. + this(const(dchar)[] str, shared Allocator allocator = defaultAllocator) + nothrow @trusted @nogc + { + this(allocator); + + bool overflow; + auto size = mulu(str.length, 4, overflow); + assert(!overflow); + + reserve(size); + + auto s = data; + foreach (c; str) + { + if (c < 0x80) + { + *s++ = c & 0x7f; + length_ += 1; + } + else if (c < 0x800) + { + *s++ = 0xc0 | (c >> 6) & 0xff; + *s++ = 0x80 | (c & 0x3f); + length_ += 2; + } + else if (c < 0xd800 || c - 0xe000 < 0x2000) + { + *s++ = 0xe0 | (c >> 12) & 0xff; + *s++ = 0x80 | ((c >> 6) & 0x3f); + *s++ = 0x80 | (c & 0x3f); + length_ += 3; + } + else if (c - 0x10000 < 0x100000) + { + *s++ = 0xf0 | (c >> 18); + *s++ = 0x80 | ((c >> 12) & 0x3f); + *s++ = 0x80 | ((c >> 6) & 0x3f); + *s++ = 0x80 | (c & 0x3f); + length_ += 4; + } + } + } + + /// + @nogc @safe unittest + { + auto s = String("Отказаться от вина - в этом страшная вина."d); + assert("Отказаться от вина - в этом страшная вина." == s.get()); + } + + /// Ditto. + this(shared Allocator allocator) pure nothrow @safe @nogc + in + { + assert(allocator !is null); + } + body + { + allocator_ = allocator; + } + + /** + * Destroys the string. + */ + ~this() nothrow @trusted @nogc + { + allocator.deallocate(data[0 .. capacity_]); + } + + /** + * Reserves $(D_PARAM size) bytes for the string. + * + * If $(D_PARAM size) is less than or equal to the $(D_PSYMBOL capacity), the + * function call does not cause a reallocation and the string capacity is not + * affected. + * + * Params: + * size = Desired size in bytes. + */ + void reserve(in size_t size) nothrow @trusted @nogc + { + if (capacity_ >= size) + { + return; + } + + void[] buf = data[0 .. capacity_]; + if (!allocator.reallocate(buf, size)) + { + onOutOfMemoryErrorNoGC(); + } + data = cast(char*) buf; + capacity_ = size; + } + + /// + @nogc @safe unittest + { + String s; + assert(s.capacity == 0); + + s.reserve(3); + assert(s.capacity == 3); + + s.reserve(3); + assert(s.capacity == 3); + + s.reserve(1); + assert(s.capacity == 3); + } + + /** + * Requests the string to reduce its capacity to fit the $(D_PARAM size). + * + * The request is non-binding. The string won't become smaller than the + * string byte length. + * + * Params: + * size = Desired size. + */ + void shrink(in size_t size) nothrow @trusted @nogc + { + if (capacity_ <= size) + { + return; + } + + immutable n = max(length_, size); + void[] buf = data[0 .. capacity_]; + if (allocator.reallocate(buf, size)) + { + capacity_ = n; + data = cast(char*) buf; + } + } + + /// + @nogc @safe unittest + { + auto s = String("Die Alten lasen laut."); + assert(s.capacity == 21); + + s.reserve(30); + s.shrink(25); + assert(s.capacity == 25); + + s.shrink(18); + assert(s.capacity == 21); + } + + /** + * Returns: String capacity in bytes. + */ + @property size_t capacity() const pure nothrow @safe @nogc + { + return capacity_; + } + + /// + @nogc @safe unittest + { + auto s = String("In allem Schreiben ist Schamlosigkeit."); + assert(s.capacity == 38); + } + + /** + * Returns an array used internally by the string. + * The length of the returned array may be smaller than the size of the + * reserved memory for the string. + * + * Returns: The array representing the string. + */ + inout(char[]) get() inout pure nothrow @trusted @nogc + { + return data[0 .. length_]; + } + + mixin DefaultAllocator; +} |