Added implementation of NSRegularExpression, from iOS 4 Foundation.

This class is a thin wrapper around libicu regular expressions, so if we don't
have libicu we simply don't compile it at all.  This will give people a linker
failure, rather than a nonfunctional class if they try to use GNUstep without
ICU with code that requires it.

The Apple documentation says that this class has a primitive method that takes
a block as an argument and that this method is called by others, so subclasses
can replace that block method without touching the convenience methods.  We
mimic this behaviour when compiling with block, but when compiling without them
it's a problem.  The current code contains some ugly hacks that will work in
normal usage but break with subclassing when not compiling with blocks.

This commit also includes a partial implementation of NSTextCheckingResult,
implementing the subset of its functionality required for NSRegularExpression
to work.

It also includes numerous fixes to GSICUString.  This is heavily used by
NSRegularExpression, to avoid copying strings when mapping between UText for
libicu and NSString for GNUstep.


Note: I don't have a copy of iOS anywhere to test this against, so it's
entirely possible that there are significant discrepancies between this
implementation of NSRegularExpression and the iOS version.  This version should
function exactly as the iOS one is described as functioning, but I think we've
all seen that Apple documentation refers more to hopes than facts.  Any testing
that someone who does have an ip{hone,od,ad} can do is very welcome.



git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@31635 72102866-910b-0410-8b05-ffd578937521

Source/GSICUString.m

@@ -1,3 +1,5 @@
+#import "config.h"
+#if HAVE_ICU
 #import "GSICUString.h"
 
 /**
@@ -16,6 +18,53 @@ static int64_t UTextNSStringNativeLength(UText *ut)
 	return [(NSString*)ut->p length];
 }
 
+
+/**
+ * Loads a group of characters into the buffer that can be directly accessed by
+ * users of the UText.  This is used for iteration but UText users.
+ */
+UBool UTextNSStringAccess(UText *ut, int64_t nativeIndex, UBool forward)
+{
+	NSString *str = ut->p;
+	NSUInteger length = [str length];
+	if (nativeIndex >= length) { return FALSE; }
+	// Special case if the chunk already contains this index
+	if (nativeIndex >= ut->chunkNativeStart
+	    && nativeIndex < (ut->chunkNativeStart + ut->chunkLength))
+	{
+		ut->chunkOffset = nativeIndex - ut->chunkNativeStart;
+		return TRUE;
+	}
+	NSRange r = {nativeIndex, chunkSize};
+	forward = TRUE;
+	if (forward)
+	{
+		if (nativeIndex + chunkSize > length)
+		{
+			r.length = length - nativeIndex;
+		}
+	}
+	else
+	{
+		if (nativeIndex - chunkSize > 0)
+		{
+			r.location = nativeIndex - chunkSize;
+			r.length = chunkSize;
+		}
+		else
+		{
+			r.location = 0;
+			r.length = chunkSize - nativeIndex;
+		}
+	}
+	[str getCharacters: ut->pExtra range: r];
+	ut->chunkNativeStart = r.location;
+	ut->chunkNativeLimit = r.location + r.length;
+	ut->chunkLength = r.length;
+	ut->chunkOffset = 0;
+	return TRUE;
+}
+
 /**
  * Replaces characters in an NSString-backed UText.
  */
@@ -41,10 +90,14 @@ static int32_t UTextNSMutableStringReplace(UText *ut,
 		                                       freeWhenDone: NO];
 	}
 	[str replaceCharactersInRange: r withString: replacement];
+
+	// Setting the chunk length to 0 here forces UTextNSStringAccess to fetch
+	// the data from the string object.
+	ut->chunkLength = 0;
+	UTextNSStringAccess(ut, r.location + [replacement length] + 1, TRUE);
+	ut->chunkOffset++;
+	
 	[replacement release];
-	// Update the chunk to reflect the internal changes.
-	r = NSMakeRange(ut->chunkNativeStart, ut->chunkLength);
-	[str getCharacters: ut->pExtra range: r];
 	if (NULL != status)
 	{
 		*status = 0;
@@ -52,51 +105,6 @@ static int32_t UTextNSMutableStringReplace(UText *ut,
 	return 0;
 }
 
-/**
- * Loads a group of characters into the buffer that can be directly accessed by
- * users of the UText.  This is used for iteration but UText users.
- */
-UBool UTextNSStringAccess(UText *ut, int64_t nativeIndex, UBool forward)
-{
-	// Special case if the chunk already contains this index
-	if (nativeIndex > ut->chunkNativeStart
-	    && nativeIndex < (ut->chunkNativeStart + ut->chunkLength))
-	{
-		ut->chunkOffset = nativeIndex - ut->chunkNativeStart;
-		return TRUE;
-	}
-	NSString *str = ut->p;
-	NSUInteger length = [str length];
-	if (nativeIndex > length) { return FALSE; }
-	NSRange r = {nativeIndex, chunkSize};
-	forward = TRUE;
-	if (forward)
-	{
-		if (nativeIndex + chunkSize > length)
-		{
-			r.length = length - nativeIndex;
-		}
-	}
-	else
-	{
-		if (nativeIndex - chunkSize > 0)
-		{
-			r.location = nativeIndex - chunkSize;
-			r.length = chunkSize;
-		}
-		else
-		{
-			r.location = 0;
-			r.length = chunkSize - nativeIndex;
-		}
-	}
-	[str getCharacters: ut->pExtra range: r];
-	ut->chunkNativeStart = r.location;
-	ut->chunkLength = r.length;
-	ut->chunkOffset = 0;
-	return TRUE;
-}
-
 /**
  * Reads some characters.  This is roughly analogous to NSString's
  * -getCharacters:range:.
@@ -216,7 +224,7 @@ UText* UTextNSMutableStringClone(UText *dest,
  */
 int64_t UTextNSStringMapOffsetToNative(const UText *ut)
 {
-	return ut->chunkNativeLimit + ut->chunkOffset;
+	return ut->chunkNativeStart + ut->chunkOffset;
 }
 
 /**
@@ -262,11 +270,12 @@ UText* UTextInitWithNSMutableString(UText *txt, NSMutableString *str)
 	UErrorCode status = 0;
 	txt = utext_setup(txt, chunkSize * sizeof(unichar), &status);
 
-	if (0 != status)  { return NULL; }
+	if (U_FAILURE(status)) { return NULL; }
 
-	txt->p = str;
+	txt->p = [str retain];
 	txt->pFuncs = &NSMutableStringFuncs;
 	txt->chunkContents = txt->pExtra;
+	txt->nativeIndexingLimit = INT32_MAX;
 
 	txt->providerProperties = 1<<UTEXT_PROVIDER_WRITABLE;
 
@@ -278,17 +287,24 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
 	UErrorCode status = 0;
 	txt = utext_setup(txt, 64, &status);
 
-	if (0 != status)  { return NULL; }
+	if (U_FAILURE(status)) { return NULL; }
 
-	txt->p = str;
+	txt->p = [str retain];
 	txt->pFuncs = &NSStringFuncs;
 	txt->chunkContents = txt->pExtra;
+	txt->nativeIndexingLimit = INT32_MAX;
 
 	return txt;
 }
 
-
 @implementation GSUTextString
+- init
+{
+	if (nil == (self = [super init])) { return nil; }
+	UText t = UTEXT_INITIALIZER;
+	memcpy(&txt, &t, sizeof(t));
+	return self;
+}
 - (NSUInteger)length
 {
 	return utext_nativeLength(&txt);
@@ -301,10 +317,10 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
 }
 - (void)getCharacters: (unichar*)buffer range: (NSRange)r
 {
-	UErrorCode status;
+	UErrorCode status = 0;
 	utext_extract(&txt, r.location, r.location+r.length, buffer, r.length,
 			&status);
-	if (0 != status)
+	if (U_FAILURE(status))
 	{
 		_NSRangeExceptionRaise();
 	}
@@ -317,6 +333,13 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
 @end
 
 @implementation GSUTextMutableString
+- init
+{
+	if (nil == (self = [super init])) { return nil; }
+	UText t = UTEXT_INITIALIZER;
+	memcpy(&txt, &t, sizeof(t));
+	return self;
+}
 - (NSUInteger)length
 {
 	return utext_nativeLength(&txt);
@@ -329,10 +352,10 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
 }
 - (void)getCharacters: (unichar*)buffer range: (NSRange)r
 {
-	UErrorCode status;
+	UErrorCode status = 0;
 	utext_extract(&txt, r.location, r.location+r.length, buffer, r.length,
 			&status);
-	if (0 != status)
+	if (U_FAILURE(status))
 	{
 		_NSRangeExceptionRaise();
 	}
@@ -341,7 +364,7 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
                       withString: (NSString*)aString
 {
 	NSUInteger size = [aString length];
-	UErrorCode status;
+	UErrorCode status = 0;
 	TEMP_BUFFER(buffer, size);
 	[aString getCharacters: buffer range: NSMakeRange(0, size)];
 
@@ -355,3 +378,4 @@ UText* UTextInitWithNSString(UText *txt, NSString *str)
 	[super dealloc];
 }
 @end
+#endif // HAV_ICU