Implement -[NSString enumerateSubstringsInRange:options:usingBlock]

2025-05-21 04:32:03 +00:00 · 2023-02-12 11:00:27 -06:00 · 2023-02-12 11:00:27 -06:00 · b8239f604f
commit b8239f604f
parent 7862434d85
3 changed files with 304 additions and 0 deletions
--- a/Source/NSString.m
+++ b/Source/NSString.m
@ -112,6 +112,14 @@
 # include <icu.h>
 #endif

+#import "Foundation/NSObjCRuntime.h"
+#import "GNUstepBase/GSBlocks.h"
+#if GS_USE_ICU
+#include <unicode/ubrk.h>
+#include <unicode/utypes.h>
+#endif
+
+
 /* Create local inline versions of key functions for case-insensitive operations
 */
 #import "Additions/unicode/caseconv.h"
@ -6248,6 +6256,156 @@ static NSFileManager *fm = nil;
  return [self rangeOfString: string].location != NSNotFound;
 }

+- (void) enumerateSubstringsInRange: (NSRange)range 
+                            options: (NSStringEnumerationOptions)opts 
+                         usingBlock: (GSNSStringEnumerationBlock)block
+{
+  // Get low byte.
+  uint8_t substringType = opts & 0xFF;
+
+  BOOL isReverse = opts & NSStringEnumerationReverse;
+  BOOL substringNotRequired = opts & NSStringEnumerationSubstringNotRequired;
+  BOOL localized = opts & NSStringEnumerationLocalized;
+  
+  NSUInteger currentLocation;
+  BOOL stop = NO;
+  if(isReverse) {
+    currentLocation = range.location + range.length;
+  } else {
+    currentLocation = range.location;
+  }
+
+  if (substringType == NSStringEnumerationByLines || substringType == NSStringEnumerationByParagraphs) {
+    BOOL isLineSep = substringType == NSStringEnumerationByLines;
+    
+    while(YES) {
+      // contains the index of the first character of the line containing the beginning of aRange.
+      NSUInteger start;
+      // contains the index of the first character past the terminator of the line containing the end of aRange.
+      NSUInteger end;
+      // contains the index of the first character of the terminator of the line containing the end of aRange. 
+      NSUInteger contentsEnd;
+      NSRange currentLocationRange = (NSRange){
+        .location = currentLocation,
+        .length = 0,
+      };
+      [self _getStart: &start 
+                  end: &end 
+          contentsEnd: &contentsEnd 
+             forRange: currentLocationRange 
+              lineSep: isLineSep];
+      // If the enumerated range starts after the line/paragraph, we start at the beginning of the enumerated range
+      NSUInteger substringStart = start > range.location ? start : range.location;
+      NSRange substringRange = (NSRange){
+        .location = substringStart,
+        .length = contentsEnd - substringStart
+      };
+      CALL_BLOCK(block, 
+        substringNotRequired ? nil : [self substringWithRange: substringRange],
+        substringRange,
+        (NSRange){
+          .location = start,
+          .length = end - start
+        },
+        &stop);
+      if(stop) break;
+      if(end == range.location + range.length) break;
+      currentLocation = end;
+    }
+  } else if (substringType == NSStringEnumerationByComposedCharacterSequences) {
+    // We could also use rangeOfComposedCharacterSequenceAtIndex:, but then we would need different logic.
+    while(YES) {
+      // Since all characters are in a composed character sequence, enclosingRange == substringRange
+      NSRange enclosingRange = [self rangeOfComposedCharacterSequenceAtIndex: currentLocation];
+      CALL_BLOCK(block, 
+        substringNotRequired ? nil : [self substringWithRange: enclosingRange],
+        enclosingRange,
+        enclosingRange,
+        &stop);
+      if(stop) break;
+      currentLocation = enclosingRange.location + enclosingRange.length;
+    }
+  } else if (substringType == NSStringEnumerationByWords || substringType == NSStringEnumerationBySentences) {
+    #if GS_USE_ICU
+    // These macros may be useful elsewhere.
+    #define GS_U_HANDLE_ERROR(errorCode, description) do { \
+      if(U_FAILURE(errorCode)) { \
+        NSWarnMLog(@"Error " description ": %s", u_errorName(errorCode)); \
+        return; \
+      } else if(errorCode < U_ZERO_ERROR) { \
+        NSWarnMLog(@"Warning " description ": %s", u_errorName(errorCode)); \
+      } \
+      errorCode = U_ZERO_ERROR; \
+    } while (NO)
+
+    BOOL byWords = substringType == NSStringEnumerationByWords;
+    NSUInteger length = range.length;
+    UChar characters[length];
+    [self getCharacters: characters range: range];
+    UErrorCode errorCode = U_ZERO_ERROR;
+    const char* locale = localized
+      ? [[[[NSLocale currentLocale] 
+                     localeIdentifier] 
+                     // @ss=standard will use lists of common abbreviations, such as Mr., Mrs., etc.
+                     stringByAppendingString: @"@ss=standard"] 
+                     UTF8String]
+      : "en_US_POSIX";
+    UBreakIterator* breakIterator = ubrk_open(byWords ? UBRK_WORD : UBRK_SENTENCE, // type
+                                              locale, // locale
+                                              characters, // text
+                                              length, // textLength
+                                              &errorCode);
+    GS_U_HANDLE_ERROR(errorCode, @"opening ICU break iterator");
+    ubrk_first(breakIterator);
+    while(YES) {
+      // Make sure it's a valid substring.
+      BOOL isValidSubstring = YES;
+      
+      if(byWords) {
+        int32_t ruleStatus = ubrk_getRuleStatus(breakIterator);
+        // From ICU User Guide:
+        //   A status value UBRK_WORD_NONE indicates that the boundary does
+        //   not start a word or number.
+        // However, valid words seem to be UBRK_WORD_NONE, and invalid words
+        // seem to be UBRK_WORD_NONE_LIMIT.
+        isValidSubstring = ruleStatus != UBRK_WORD_NONE_LIMIT;
+        NSLog(@"Status for position %d (%d): %d", (int)currentLocation, (int)ubrk_current(breakIterator), (int) ruleStatus);
+      }
+      int32_t nextPosition = ubrk_next(breakIterator);
+      if(nextPosition == UBRK_DONE) break;
+      NSUInteger nextLocation = range.location + nextPosition;
+      // Same as substringRange
+      NSRange enclosingRange = (NSRange){
+        .location = currentLocation,
+        .length = nextLocation - currentLocation
+      };
+      
+      if(isValidSubstring) {
+        CALL_BLOCK(block, 
+          substringNotRequired ? nil : [self substringWithRange: enclosingRange],
+          enclosingRange,
+          enclosingRange,
+          &stop);
+        if(stop) break;
+      }
+
+      currentLocation = nextLocation;
+    }
+    #else
+    NSWarnLog(@"NSStringEnumerationByWords and NSStringEnumerationBySentences are not supported when GNUstep-base is compiled without ICU.");
+    return;
+    #endif
+  } else if (substringType == NSStringEnumerationByCaretPositions) {
+    // FIXME - Not documented by Apple.
+    NSWarnLog(@"NSStringEnumerationByCaretPositions is not supported");
+    return;
+  } else if (substringType == NSStringEnumerationByDeletionClusters) {
+    // FIXME - Not documented by Apple.
+    NSWarnLog(@"NSStringEnumerationByDeletionClusters is not supported");
+    return;
+  }
+}
+
@end

 /**