ICU-23307 Space-sensitive UnicodeSet string literals

Author: eggrobin

icu4c/source/common/uniset_props.cpp

@@ -538,9 +538,9 @@ class UnicodeSet::Lexer {
             UChar32 next;
             int32_t codePointCount = 0;
             while (!chars_.atEnd() && U_SUCCESS(errorCode)) {
-                // TODO(egg): Propose making this space-sensitive.
                 const RuleCharacterIterator::Pos beforeNext = getPos();
-                next = chars_.next(charsOptions_ & ~RuleCharacterIterator::PARSE_ESCAPES,
+                next = chars_.next(charsOptions_ & ~(RuleCharacterIterator::PARSE_ESCAPES |
+                                                     RuleCharacterIterator::SKIP_WHITESPACE),
                                    unusedEscaped, errorCode);
                 if (next == u'\\') {
                     if (chars_.next(charsOptions_ & ~(RuleCharacterIterator::PARSE_ESCAPES |

icu4c/source/test/intltest/usettest.cpp

@@ -4633,8 +4633,8 @@ void UnicodeSetTest::TestToPatternOutput() {
             {u"[ - - ]", uR"([\-])"},
             {u"[ - _ - ]", uR"([\-_])"},
             {u"[ - + - ]", uR"([+\-])"},
-            {u"[ { Z e i c h e n k e t t e } Zeichenmenge ]", u"[Zceg-imn{Zeichenkette}]"},
-            {uR"([ { \x5A e i c h e n k e t t e } \x5Aeichenmenge ])", u"[Zceg-imn{Zeichenkette}]"},
+            {u"[ { Z e i c h e n k e t t e } Zeichenmenge ]", uR"([Zceg-imn{\ Z\ e\ i\ c\ h\ e\ n\ k\ e\ t\ t\ e\ }])"},
+            {uR"([ { \x5A e i c h e n k e t t e } \x5Aeichenmenge ])", uR"([Zceg-imn{\ Z\ e\ i\ c\ h\ e\ n\ k\ e\ t\ t\ e\ }])"},
             {u"[$d-za-c]", uR"([\$a-z])"},
             {u"[a-c$d-z]", uR"([\$a-z])"},
             {uR"([\uFFFFa-z])", uR"([a-z\uFFFF])"},
@@ -4659,10 +4659,10 @@ void UnicodeSetTest::TestToPatternOutput() {
             {uR"([ ^ [ \u0000-b d-\U0010FFFF ] ])", uR"([^[^c]])"},
             {u"[$[]]", uR"([\$[]])"},
             // Spaces are eliminated within a string-literal even when the syntax is preserved.
-            {u"[ {Z e i c h e n k e t t e } [] Zeichenmenge ]", u"[{Zeichenkette}[]Zeichenmenge]"},
+            {u"[ { Z e i c h e n k e t t e } [] Zeichenmenge ]", uR"([{\ Z\ e\ i\ c\ h\ e\ n\ k\ e\ t\ t\ e\ }[]Zeichenmenge])"},
             // Escapes are removed even when the syntax is preserved.
             {uR"([ { \x5A e i c h e n k e t t e } [] \x5Aeichenmenge ])",
-            u"[{Zeichenkette}[]Zeichenmenge]"},
+            uR"([{\ Z\ e\ i\ c\ h\ e\ n\ k\ e\ t\ t\ e\ }[]Zeichenmenge])"},
             // In ICU 78 and earlier, a named-element was a nested set, so it was preserved and
             // caused the syntax to be preserved.  Now it is treated like an escape.
             {uR"([ \N{LATIN CAPITAL LETTER Z}eichenmenge ])", uR"([Zceg-imn])"},