/* Copyright (C) 2003-2013 Runtime Revolution Ltd

This file is part of LiveCode.

LiveCode is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License v3 as published by the Free

Software Foundation.

LiveCode is distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License

for more details.

You should have received a copy of the GNU General Public License

along with LiveCode. If not see <http://www.gnu.org/licenses/>. */

#include <foundation.h>

#include <foundation-auto.h>

#include <foundation-unicode.h>

#include "foundation-private.h"

#include "foundation-bidi.h"

#ifdef __LINUX__

#include <errno.h>

#include <iconv.h>

#include <langinfo.h>

#include <locale.h>

#endif

#ifdef __WINDOWS__

#include <windows.h>

#endif

////////////////////////////////////////////////////////////////////////////////

// CAVEAT!

//

// The currently implementation of the string value is native-only. Although

// the main (Unicode) methods will work, the input will get coerced to native

// encoding.

//

// When all the work is done to change the engine to use MCValueRef exclusively,

// gaining full transparent Unicode *should* just be a case of reimplementing

// the string value!

// NOTE!

//

// As it stands the underlying (native) char buffer always has an implicit NUL

// terminator added on. This is merely an aid to integration until all the uses

// of the legacy 'NativeCString' method is eliminated from use in the engine

// (which is pre-requisite for unicodification).

////////////////////////////////////////////////////////////////////////////////

// This method ensures there is 'count' chars of empty space starting at 'at'

// in 'string'. It returns false if allocation fails.

static bool __MCStringExpandAt(MCStringRef string, uindex_t at, uindex_t count);

// This method removes 'count' chars from string starting at 'at'.

static void __MCStringShrinkAt(MCStringRef string, uindex_t at, uindex_t count);

// This method clamps the given range to the valid limits for the string.

static void __MCStringClampRange(MCStringRef string, MCRange& x_range);

// This method forces a nativization of a string even if there is already a native char ptr.

static uindex_t __MCStringNativize(MCStringRef string);

// This method ensures there is a unichar ptr.

static void __MCStringUnnativize(MCStringRef self);

// This method marks the string as changed.

static void __MCStringChanged(MCStringRef string, uindex_t simple = kMCStringFlagNoChange, uindex_t combined = kMCStringFlagNoChange, uindex_t native = kMCStringFlagNoChange);

// Creates an indirect mutable string with contents.

static bool __MCStringCreateIndirect(__MCString *contents, __MCString*& r_string);

// Returns true if the string is indirect.

static bool __MCStringIsIndirect(__MCString *self);

static bool __MCStringMakeImmutable(__MCString *self);

// Creates an immutable string from this one, changing 'self' to indirect.

static bool __MCStringMakeIndirect(__MCString *self);

// Ensures the given mutable but indirect string is direct.

static bool __MCStringResolveIndirect(__MCString *self);

// Makes direct mutable string indirect, referencing r_new_string.

static bool __MCStringCopyMutable(__MCString *self, __MCString*& r_new_string);

////////////////////////////////////////////////////////////////////////////////

// AL-2015-02-06: [[ Bug 14504 ]] Add wrappers for string flag and length checking,

// for internal use when a string is known to be direct.

static bool __MCStringIsNative(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return (self -> flags & kMCStringFlagIsNotNative) == 0;

}

static bool __MCStringIsChecked(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return (self -> flags & kMCStringFlagIsChecked) != 0;

}

static bool __MCStringIsUncombined(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return (self -> flags & kMCStringFlagIsUncombined) != 0;

}

static bool __MCStringIsSimple(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return (self -> flags & kMCStringFlagIsSimple) != 0;

}

static bool __MCStringCanBeNative(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return (self -> flags & kMCStringFlagIsNotNative) == 0 || (self -> flags & kMCStringFlagCanBeNative) != 0;

}

static bool __MCStringCantBeNative(MCStringRef self, MCStringOptions p_options)

{

return ((!__MCStringCanBeNative(self) && (p_options == kMCStringOptionCompareExact || p_options == kMCStringOptionCompareFolded))

|| (__MCStringIsChecked(self) && __MCStringIsUncombined(self)));

}

static uindex_t __MCStringGetLength(MCStringRef self)

{

MCAssert(!__MCStringIsIndirect(self));

return self -> char_count;

}

static bool __MCStringIsEmpty(MCStringRef string)

{

return string == nil || __MCStringGetLength(string) == 0;

}

////////////////////////////////////////////////////////////////////////////////

// This method creates a 'constant' MCStringRef from the given c-string. At some

// point we'll make it work 'magically' at compile/build time. For now, uniquing

// and returning that has a similar effect (if slightly slower).

MCStringRef MCSTR(const char *p_cstring)

{

MCStringRef t_string;

/* UNCHECKED */ MCStringCreateWithNativeChars((const char_t *)p_cstring, strlen(p_cstring), t_string);

MCValueRef t_unique_string;

/* UNCHECKED */ MCValueInter(t_string, t_unique_string);

MCValueRelease(t_string);

return (MCStringRef)t_unique_string;

}

////////////////////////////////////////////////////////////////////////////////

bool MCStringCreateWithCString(const char* p_cstring, MCStringRef& r_string)

{

return MCStringCreateWithNativeChars((const char_t*)p_cstring, p_cstring == nil ? 0 : strlen(p_cstring), r_string);

}

bool MCStringCreateWithCStringAndRelease(char* p_cstring, MCStringRef& r_string)

{

if (MCStringCreateWithNativeChars((const char_t *)p_cstring, p_cstring == nil ? 0 : strlen((const char*)p_cstring), r_string))

{

delete p_cstring;

return true;

}

return false;

}

const char *MCStringGetCString(MCStringRef p_string)

{

if (p_string == nil)

return nil;

MCStringNativize(p_string);

const char *t_cstring;

t_cstring = (const char *)MCStringGetNativeCharPtr(p_string);

MCAssert(t_cstring != nil);

return t_cstring;

}

bool MCStringIsEqualToCString(MCStringRef p_string, const char *p_cstring, MCStringOptions p_options)

{

return MCStringIsEqualToNativeChars(p_string, (const char_t *)p_cstring, strlen(p_cstring), p_options);

}

// Create an immutable string from the given bytes, interpreting them using

// the specified encoding.

bool MCStringCreateWithBytes(const byte_t *p_bytes, uindex_t p_byte_count, MCStringEncoding p_encoding, bool p_is_external_rep, MCStringRef& r_string)

{

MCAssert(!p_is_external_rep);

switch (p_encoding)

{

case kMCStringEncodingASCII:

case kMCStringEncodingNative:

return MCStringCreateWithNativeChars(p_bytes, p_byte_count, r_string);

case kMCStringEncodingUTF16:

return MCStringCreateWithChars((unichar_t *)p_bytes, p_byte_count / 2, r_string);

// AL-2014-31-03: [[ Bug 12067 ]] Fix conversion from little endian bytes.

case kMCStringEncodingUTF16LE:

case kMCStringEncodingUTF16BE:

{

unichar_t *t_buffer;

uindex_t t_length = p_byte_count / 2;

MCMemoryAllocate(t_length * sizeof(unichar_t), t_buffer);

for (uindex_t i = 0; i < t_length; i++)

{

if (p_encoding == kMCStringEncodingUTF16BE)

t_buffer[i] = (unichar_t)MCSwapInt16BigToHost(((unichar_t *)p_bytes)[i]);

else

t_buffer[i] = (unichar_t)MCSwapInt16LittleToHost(((unichar_t *)p_bytes)[i]);

}

return MCStringCreateWithCharsAndRelease(t_buffer, t_length, r_string);

}

case kMCStringEncodingUTF8:

{

unichar_t *t_chars;

uindex_t t_char_count;

t_char_count = MCUnicodeCharsMapFromUTF8(p_bytes, p_byte_count, nil, 0);

if (!MCMemoryNewArray(t_char_count, t_chars))

return false;

MCUnicodeCharsMapFromUTF8(p_bytes, p_byte_count, t_chars, t_char_count);

if (!MCStringCreateWithCharsAndRelease(t_chars, t_char_count, r_string))

{

MCMemoryDeleteArray(t_chars);

return false;

}

return true;

}

break;

case kMCStringEncodingUTF32:

case kMCStringEncodingUTF32LE:

case kMCStringEncodingUTF32BE:

{

// Round the byte count to a multiple of UTF-32 units

p_byte_count = ((p_byte_count + sizeof(uint32_t) - 1) & ~(sizeof(uint32_t) - 1));

// Convert the string to UTF-16 first. The UTF-16 string cannot be longer than the UTF-32 string

MCAutoArray<unichar_t> t_buffer;

t_buffer.Extend(p_byte_count / sizeof(uint32_t));

uindex_t t_in_offset;

uindex_t t_out_offset = 0;

for (t_in_offset = 0; t_in_offset < p_byte_count; t_in_offset += sizeof(uint32_t))

{

// BMP characters are output unchanged, non-BMP requires surrogate pairs

codepoint_t t_codepoint;

t_codepoint = *(uint32_t*)&p_bytes[t_in_offset];

if (p_encoding == kMCStringEncodingUTF32BE)

t_codepoint = MCSwapInt32BigToHost(t_codepoint);

else if (p_encoding == kMCStringEncodingUTF32LE)

t_codepoint = MCSwapInt32LittleToHost(t_codepoint);

if (t_codepoint < 0x10000)

{

t_buffer[t_out_offset] = unichar_t(t_codepoint);

t_out_offset += 1;

}

else

{

// Split to surrogate pairs

unichar_t t_lead, t_trail;

t_lead = unichar_t((t_codepoint - 0x10000) >> 10) + 0xD800;

t_trail = unichar_t((t_codepoint - 0x10000) & 0x3FF) + 0xDC00;

t_buffer[t_out_offset] = t_lead;

t_buffer[t_out_offset + 1] = t_trail;

t_out_offset += 2;

}

}

return MCStringCreateWithChars(t_buffer.Ptr(), t_out_offset, r_string);

}

break;

#if !defined(__LINUX__) && !defined(__ANDROID__)

case kMCStringEncodingISO8859_1:

break;

#endif

#ifndef __WINDOWS__

case kMCStringEncodingWindows1252:

break;

#endif

#if !defined(__MAC__) && !defined(__IOS__)

case kMCStringEncodingMacRoman:

break;

#endif

}

return false;

}

bool MCStringCreateWithBytesAndRelease(byte_t *p_bytes, uindex_t p_byte_count, MCStringEncoding p_encoding, bool p_is_external_rep, MCStringRef& r_string)

{

MCStringRef t_string;

t_string = nil;

switch (p_encoding)

{

case kMCStringEncodingASCII:

case kMCStringEncodingNative:

break;

default:

if (!MCStringCreateWithBytes(p_bytes, p_byte_count, p_encoding, p_is_external_rep, t_string))

return false;

r_string = t_string;

free(p_bytes);

return true;

}

bool t_success;

t_success = true;

if (p_byte_count == 0 && kMCEmptyString != nil)

{

r_string = MCValueRetain(kMCEmptyString);

free(p_bytes);

return true;

}

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, t_string);

if (t_success)

t_success = MCMemoryReallocate(p_bytes, p_byte_count + 1, p_bytes);

if (t_success)

{

p_bytes[p_byte_count] = '\0';

t_string -> native_chars = p_bytes;

t_string -> char_count = p_byte_count;

r_string = t_string;

}

else

MCMemoryDelete(t_string);

return t_success;

}

////////////////////////////////////////////////////////////////////////////////

bool MCStringCreateWithChars(const unichar_t *p_chars, uindex_t p_char_count, MCStringRef& r_string)

{

if (p_char_count == 0 && kMCEmptyString != nil)

{

r_string = MCValueRetain(kMCEmptyString);

return true;

}

bool t_success;

t_success = true;

__MCString *self;

self = nil;

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, self);

bool t_not_native;

t_not_native = false;

if (t_success)

t_success = MCMemoryNewArray(p_char_count + 1, self -> native_chars);

if (t_success)

{

uindex_t i;

for(i = 0; i < p_char_count; i++)

if (!MCUnicodeCharMapToNative(p_chars[i], self -> native_chars[i]))

{

t_not_native = true;

break;

}

if (t_not_native)

{

MCMemoryDeleteArray(self -> native_chars);

t_success = MCMemoryNewArray(p_char_count + 1, self -> chars);

}

}

if (t_success)

{

if (t_not_native)

{

MCStrCharsMapFromUnicode(p_chars, p_char_count, self -> chars, self -> char_count);

self -> flags |= kMCStringFlagIsNotNative;

}

else

self -> char_count = p_char_count;

r_string = self;

}

else

{

if (self != nil)

MCMemoryDeleteArray(self -> chars);

MCMemoryDelete(self);

}

return t_success;

}

bool MCStringCreateWithCharsAndRelease(unichar_t *p_chars, uindex_t p_char_count, MCStringRef& r_string)

{

if (MCStringCreateWithChars(p_chars, p_char_count, r_string))

{

free(p_chars);

return true;

}

return false;

}

bool MCStringCreateWithWString(const unichar_t *p_wstring, MCStringRef& r_string)

{

uindex_t t_length;

for(t_length = 0; p_wstring[t_length] != 0; t_length++)

;

return MCStringCreateWithChars(p_wstring, t_length, r_string);

}

bool MCStringCreateWithWStringAndRelease(unichar_t* p_wstring, MCStringRef& r_string)

{

if (MCStringCreateWithWString(p_wstring, r_string))

{

free(p_wstring);

return true;

}

return false;

}

bool MCStringCreateWithNativeChars(const char_t *p_chars, uindex_t p_char_count, MCStringRef& r_string)

{

bool t_success;

t_success = true;

if (p_char_count == 0 && kMCEmptyString != nil)

{

r_string = MCValueRetain(kMCEmptyString);

return true;

}

__MCString *self;

self = nil;

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, self);

if (t_success)

t_success = MCMemoryNewArray(p_char_count + 1, self -> native_chars);

if (t_success)

MCMemoryCopy(self -> native_chars, p_chars, p_char_count);

else

{

if (self != nil)

MCMemoryDeleteArray(self -> native_chars);

MCMemoryDelete(self);

}

if (t_success)

{

self -> char_count = p_char_count;

r_string = self;

}

return t_success;

}

bool MCStringCreateWithNativeCharsAndRelease(char_t *p_chars, uindex_t p_char_count, MCStringRef& r_string)

{

bool t_success;

t_success = true;

if (p_char_count == 0 && kMCEmptyString != nil)

{

r_string = MCValueRetain(kMCEmptyString);

MCMemoryDeallocate(p_chars);

return true;

}

__MCString *self;

self = nil;

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, self);

if (t_success)

t_success = MCMemoryReallocate(p_chars, p_char_count + 1, p_chars);

if (t_success)

{

p_chars[p_char_count] = '\0';

self -> native_chars = p_chars;

self -> char_count = p_char_count;

r_string = self;

}

else

MCMemoryDelete(self);

return t_success;

}

static bool MCStringCreateMutableUnicode(uindex_t p_initial_capacity, MCStringRef& r_string)

{

bool t_success;

t_success = true;

__MCString *self;

self = nil;

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, self);

if (t_success)

{

self -> flags |= kMCStringFlagIsNotNative;

t_success = __MCStringExpandAt(self, 0, p_initial_capacity);

}

if (t_success)

{

self -> flags |= kMCStringFlagIsMutable;

self->char_count = 0;

r_string = self;

}

else

{

MCValueRelease (self);

}

return t_success;

}

bool MCStringCreateMutable(uindex_t p_initial_capacity, MCStringRef& r_string)

{

bool t_success;

t_success = true;

__MCString *self;

self = nil;

if (t_success)

t_success = __MCValueCreate(kMCValueTypeCodeString, self);

if (t_success)

t_success = __MCStringExpandAt(self, 0, p_initial_capacity);

if (t_success)

{

self -> flags |= kMCStringFlagIsMutable;

self->char_count = 0;

r_string = self;

}

else

{

MCValueRelease (self);

}

return t_success;

}

////////////////////////////////////////////////////////////////////////////////

bool MCStringEncode(MCStringRef p_string, MCStringEncoding p_encoding, bool p_is_external_rep, MCDataRef& r_data)

{

byte_t *t_bytes;

uindex_t t_byte_count;

if (!MCStringConvertToBytes(p_string, p_encoding, p_is_external_rep, t_bytes, t_byte_count))

return false;

if (!MCDataCreateWithBytesAndRelease(t_bytes, t_byte_count, r_data))

{

free(t_bytes);

return false;

}

return true;

}

bool MCStringEncodeAndRelease(MCStringRef p_string, MCStringEncoding p_encoding, bool p_is_external_rep, MCDataRef& r_data)

{

MCDataRef t_data;

if (!MCStringEncode(p_string, p_encoding, p_is_external_rep, t_data))

return false;

MCValueRelease(p_string);

r_data = t_data;

return true;

}

bool MCStringDecode(MCDataRef p_data, MCStringEncoding p_encoding, bool p_is_external_rep, MCStringRef& r_string)

{

return MCStringCreateWithBytes(MCDataGetBytePtr(p_data), MCDataGetLength(p_data), p_encoding, p_is_external_rep, r_string);

}

bool MCStringDecodeAndRelease(MCDataRef p_data, MCStringEncoding p_encoding, bool p_is_external_rep, MCStringRef& r_string)

{

MCStringRef t_string;

if (!MCStringDecode(p_data, p_encoding, p_is_external_rep, t_string))

return false;

MCValueRelease(p_data);

r_string = t_string;

return true;

}

////////////////////////////////////////////////////////////////////////////////

static bool __MCStringFormatSupportedForUnicode(const char *p_format)

{

while(*p_format != '\0')

{

if (*p_format == '%' &&

(p_format[1] != 's' && p_format[1] != 'd' && p_format[1] != '@'))

return false;

if (*p_format == '\\' &&

(p_format[1] != 'n' && p_format[1] != '"'))

return false;

p_format++;

}

return true;

}

#if defined(__32_BIT__)

#define FORMAT_ARG_32_BIT 1

#define FORMAT_ARG_64_BIT 2

#elif defined(__64_BIT__)

#define FORMAT_ARG_32_BIT 1

#define FORMAT_ARG_64_BIT 1

#endif

bool MCStringFormatV(MCStringRef& r_string, const char *p_format, va_list p_args)

{

MCStringRef t_buffer;

if (!MCStringCreateMutable(0, t_buffer))

return false;

bool t_success;

t_success = true;

const char *t_format_ptr;

t_format_ptr = p_format;

while(t_success && *t_format_ptr != '\0')

{

const char *t_format_start_ptr;

t_format_start_ptr = t_format_ptr;

bool t_has_range;

t_has_range = false;

int t_arg_count;

t_arg_count = 0;

while(*t_format_ptr != '\0')

{

if (*t_format_ptr == '%')

{

// AL-2014-09-19: Flush chars between format strings

if (t_format_ptr != t_format_start_ptr)

break;

t_format_ptr++;

if (*t_format_ptr == '@')

break;

// AL-2014-11-19: [[ Bug 14059 ]] Add support for variable length zero padding

if (*t_format_ptr == '0')

t_format_ptr++;

if (*t_format_ptr == '*')

{

t_arg_count += FORMAT_ARG_32_BIT;

t_format_ptr++;

if (*t_format_ptr == '@')

{

t_format_start_ptr = t_format_ptr;

t_has_range = true;

break;

}

}

else

{

while(*t_format_ptr != '\0' && isdigit(*t_format_ptr))

t_format_ptr++;

}

if (*t_format_ptr == '.')

{

t_format_ptr++;

if (*t_format_ptr == '*')

{

t_arg_count += FORMAT_ARG_32_BIT;

t_format_ptr++;

}

else

{

while(*t_format_ptr != '\0' && isdigit(*t_format_ptr))

t_format_ptr++;

}

}

// MW-2014-10-23: [[ Bug 13757 ]] Make sure we process the VS specific 'I64d' format

// as 64-bit.

if (strncmp(t_format_ptr, "lld", 3) == 0 ||

strncmp(t_format_ptr, "llu", 3) == 0 ||

strncmp(t_format_ptr, "lf", 2) == 0 ||

strncmp(t_format_ptr, "f", 1) == 0 ||

strncmp(t_format_ptr, "g", 1) == 0 ||

strncmp(t_format_ptr, "I64d", 4) == 0)

t_arg_count += FORMAT_ARG_64_BIT;

// SN-2015-01-05: [[ Bug 14304 ]] There is no argument to be popped from the list

// if we are considering a "%%" sequence

else if (*t_format_ptr != '%')

t_arg_count += FORMAT_ARG_32_BIT;

}

t_format_ptr += 1;

}

if (t_format_start_ptr != t_format_ptr)

{

char *t_format;

uint32_t t_format_size;

// [[ vsnprintf ]] On Linux, the trailing '%' from '%@' placeholder causes vsprintf to fail

// and return -1 in MCNativeCharsFormat (and thus creates a 0-byte sized array).

if (*t_format_ptr == '@' && *(t_format_ptr - 1) == '%')

t_format_size = t_format_ptr - t_format_start_ptr - 1;

else

t_format_size = t_format_ptr - t_format_start_ptr;

/* UNCHECKED */ t_format = (char *)malloc(t_format_size + 1);

if (t_format == nil)

t_success = false;

char_t *t_string;

uindex_t t_size;

t_string = nil;

if (t_success)

{

memcpy(t_format, t_format_start_ptr, t_format_size);

t_format[t_format_size] = '\0';

#if defined(_WINDOWS) || defined(_WINDOWS_SERVER)

t_success = MCNativeCharsFormatV(t_string, t_size, t_format, p_args);

#else

va_list t_args;

va_copy(t_args, p_args);

t_success = MCNativeCharsFormatV(t_string, t_size, t_format, t_args);

va_end(t_args);

#endif

}

if (t_success)

t_success = MCStringAppendNativeChars(t_buffer, t_string, t_size);

if (t_success)

while(t_arg_count > 0)

{

va_arg(p_args, uintptr_t);

t_arg_count -= 1;

}

MCMemoryDeallocate(t_string);

free(t_format);

}

if (t_success && *t_format_ptr == '@')

{

t_format_ptr += 1;

const MCRange *t_range;

if (t_has_range)

t_range = va_arg(p_args, const MCRange *);

else

t_range = nil;

MCValueRef t_value;

t_value = va_arg(p_args, MCValueRef);

MCAutoStringRef t_string;

if (MCValueGetTypeCode(t_value) == kMCValueTypeCodeString)

t_string = (MCStringRef)t_value;

else

/* UNCHECKED */ MCValueCopyDescription (t_value, &t_string);

if (t_range == nil)

t_success = MCStringAppend(t_buffer, *t_string);

else

t_success = MCStringAppendSubstring(t_buffer, *t_string, *t_range);

}

}

if (t_success)

t_success = MCStringCopyAndRelease(t_buffer, r_string);

if (!t_success)

MCValueRelease (t_buffer);

return t_success;

}

bool MCStringFormat(MCStringRef& r_string, const char *p_format, ...)

{

bool t_success;

va_list t_args;

va_start(t_args, p_format);

t_success = MCStringFormatV(r_string, p_format, t_args);

va_end(t_args);

return t_success;

}

////////////////////////////////////////////////////////////////////////////////

static bool __MCStringCloneBuffer(MCStringRef self, unichar_t*& chars, uindex_t& char_count)

{

MCAssert(!__MCStringIsIndirect(self));

if (MCMemoryNewArray(self -> char_count + 1, chars))

{

MCStrCharsMapFromUnicode(self -> chars, self -> char_count, chars, char_count);

return true;

}

return false;

}

static bool __MCStringCloneNativeBuffer(MCStringRef self, char_t*& chars, uindex_t& char_count)

{

MCAssert(!__MCStringIsIndirect(self));

if (MCMemoryNewArray(self -> char_count + 1, chars))

{

MCMemoryCopy(chars, self -> native_chars, self -> char_count);

char_count = self -> char_count;

return true;

}

return false;

}

bool MCStringCopy(MCStringRef self, MCStringRef& r_new_string)

{

// If the string is immutable we can just bump the reference count.

if (!MCStringIsMutable(self))

{

r_new_string = self;

MCValueRetain(self);

return true;

}

// If it is mutable and indirect then retain the referenced string

if (__MCStringIsIndirect(self))

{

r_new_string = MCValueRetain(self -> string);

return true;

}

// Otherwise make the mutable direct string immutable,

// assign the new string as that, and make self indirect

// referencing it.

return __MCStringCopyMutable(self, r_new_string);

}

bool MCStringCopyAndRelease(MCStringRef self, MCStringRef& r_new_string)

{

// If the string is immutable we just pass it through (as we are releasing the string).

if (!MCStringIsMutable(self))

{

r_new_string = self;

return true;

}

// If the string is indirect then retain its reference, and release

if (__MCStringIsIndirect(self))

{

r_new_string = MCValueRetain(self -> string);

MCValueRelease(self);

return true;

}

// If the reference count is one, then shrink the buffer and mark as immutable.

if (self -> references == 1)

{

__MCStringMakeImmutable(self);

self -> flags &= ~kMCStringFlagIsMutable;

self -> capacity = 0;

r_new_string = self;

return true;

}

// Otherwise, make a new indirect string

if (!__MCStringMakeIndirect(self))

return false;

// Reduce reference count

self -> references -= 1;

// And return a copy of the string

r_new_string = MCValueRetain(self -> string);

return true;

}

bool MCStringMutableCopy(MCStringRef self, MCStringRef& r_new_string)

{

// If self is immutable, then the new mutable string will be indirect

// referencing it.

if (!MCStringIsMutable(self))

return __MCStringCreateIndirect(self, r_new_string);

// If the string is already indirect, we just create a new reference to its string

if (__MCStringIsIndirect(self))

return __MCStringCreateIndirect(self -> string, r_new_string);

// If the string is mutable, we make it indirect and share

// the indirect copy.

if (!__MCStringMakeIndirect(self))

return false;

return __MCStringCreateIndirect(self -> string, r_new_string);

}

bool MCStringMutableCopyAndRelease(MCStringRef self, MCStringRef& r_new_string)

{

if (self -> references == 1)

{

if (!MCStringIsMutable(self))

{

self -> flags |= kMCStringFlagIsMutable;

//self -> capacity = self -> char_count;

}

r_new_string = self;

return true;

}

if (!MCStringMutableCopy(self, r_new_string))

return false;

self -> references -= 1;

return true;

}

////////////////////////////////////////////////////////////////////////////////

bool MCStringCopySubstring(MCStringRef self, MCRange p_range, MCStringRef& r_substring)

{

if (__MCStringIsIndirect(self))

self = self -> string;

// Avoid copying in case the substring is actually the whole string

if (p_range . offset == 0 && self -> char_count < p_range . length)

return MCStringCopy(self, r_substring);

__MCStringClampRange(self, p_range);

if (__MCStringIsNative(self))

return MCStringCreateWithNativeChars(self -> native_chars + p_range . offset, p_range . length, r_substring);

return MCStringCreateWithChars(self -> chars + p_range . offset, p_range . length, r_substring);

}

bool MCStringCopySubstringAndRelease(MCStringRef self, MCRange p_range, MCStringRef& r_substring)

{

if (MCStringCopySubstring(self, p_range, r_substring))

{

MCValueRelease(self);

return true;

}

return false;