Equivalize isLowerCase and isUpperCase behavior in all platforms #KT-46184

libraries/stdlib/js/src/generated/_LetterChars.kt

@@ -51,17 +51,17 @@ internal fun Char.isLetterImpl(): Boolean {
 }
 
 /**
- * Returns `true` if this character is a lower case letter.
+ * Returns `true` if this character is a lower case letter, or it has contributory property Other_Lowercase.
  */
 internal fun Char.isLowerCaseImpl(): Boolean {
-    return getLetterType() == 1
+    return getLetterType() == 1 || code.isOtherLowercase()
 }
 
 /**
- * Returns `true` if this character is an upper case letter.
+ * Returns `true` if this character is an upper case letter, or it has contributory property Other_Uppercase.
  */
 internal fun Char.isUpperCaseImpl(): Boolean {
-    return getLetterType() == 2
+    return getLetterType() == 2 || code.isOtherUppercase()
 }
 
 /**

libraries/stdlib/js/src/generated/_OtherLowercaseChars.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.text
+
+//
+// NOTE: THIS FILE IS AUTO-GENERATED by the GenerateUnicodeData.kt
+// See: https://github.com/JetBrains/kotlin/tree/master/libraries/stdlib
+//
+
+private object OtherLowercase {
+    internal val otherLowerStart = intArrayOf(
+        0x00aa, 0x00ba, 0x02b0, 0x02c0, 0x02e0, 0x0345, 0x037a, 0x1d2c, 0x1d78, 0x1d9b, 0x2071, 0x207f, 0x2090, 0x2170, 0x24d0, 0x2c7c, 0xa69c, 0xa770, 0xa7f8, 0xab5c, 
+    )
+    internal val otherLowerLength = intArrayOf(
+        1, 1, 9, 2, 5, 1, 1, 63, 1, 37, 1, 1, 13, 16, 26, 2, 2, 1, 2, 4, 
+    )
+}
+
+internal fun Int.isOtherLowercase(): Boolean {
+    val index = binarySearchRange(OtherLowercase.otherLowerStart, this)
+    return index >= 0 && this < OtherLowercase.otherLowerStart[index] + OtherLowercase.otherLowerLength[index]
+}

libraries/stdlib/js/src/generated/_OtherUppercaseChars.kt

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.text
+
+//
+// NOTE: THIS FILE IS AUTO-GENERATED by the GenerateUnicodeData.kt
+// See: https://github.com/JetBrains/kotlin/tree/master/libraries/stdlib
+//
+
+internal fun Int.isOtherUppercase(): Boolean {
+    return this in 0x2160..0x216f
+            || this in 0x24b6..0x24cf
+}

libraries/stdlib/js/src/kotlin/text/char.kt

@@ -181,9 +181,10 @@ public actual fun Char.isDigit(): Boolean {
 }
 
 /**
- * Returns `true` if this character is an upper case letter.
+ * Returns `true` if this character is upper case.
  *
- * A character is considered to be an upper case letter if its [category] is [CharCategory.UPPERCASE_LETTER].
+ * A character is considered to be an upper case character if its [category] is [CharCategory.UPPERCASE_LETTER],
+ * or it has contributory property Other_Uppercase as defined by the Unicode Standard.
  *
  * @sample samples.text.Chars.isUpperCase
  */
@@ -199,9 +200,10 @@ public actual fun Char.isUpperCase(): Boolean {
 }
 
 /**
- * Returns `true` if this character is a lower case letter.
+ * Returns `true` if this character is lower case.
  *
- * A character is considered to be a lower case letter if its [category] is [CharCategory.LOWERCASE_LETTER].
+ * A character is considered to be a lower case character if its [category] is [CharCategory.LOWERCASE_LETTER],
+ * or it has contributory property Other_Lowercase as defined by the Unicode Standard.
  *
  * @sample samples.text.Chars.isLowerCase
  */