Commonize and generalize JVM-only String.contentEquals #KT-42840

libraries/stdlib/api/js-v1/kotlin.text.kt

@@ -162,6 +162,12 @@ public operator fun kotlin.CharSequence.contains(other: kotlin.CharSequence, ign
 @kotlin.internal.InlineOnly
 public inline operator fun kotlin.CharSequence.contains(regex: kotlin.text.Regex): kotlin.Boolean
 
+@kotlin.SinceKotlin(version = "1.5")
+public infix fun kotlin.CharSequence?.contentEquals(other: kotlin.CharSequence?): kotlin.Boolean
+
+@kotlin.SinceKotlin(version = "1.5")
+public fun kotlin.CharSequence?.contentEquals(other: kotlin.CharSequence?, ignoreCase: kotlin.Boolean): kotlin.Boolean
+
 @kotlin.internal.InlineOnly
 public inline fun kotlin.CharSequence.count(): kotlin.Int
 

libraries/stdlib/api/js/kotlin.text.kt

@@ -162,6 +162,12 @@ public operator fun kotlin.CharSequence.contains(other: kotlin.CharSequence, ign
 @kotlin.internal.InlineOnly
 public inline operator fun kotlin.CharSequence.contains(regex: kotlin.text.Regex): kotlin.Boolean
 
+@kotlin.SinceKotlin(version = "1.5")
+public infix fun kotlin.CharSequence?.contentEquals(other: kotlin.CharSequence?): kotlin.Boolean
+
+@kotlin.SinceKotlin(version = "1.5")
+public fun kotlin.CharSequence?.contentEquals(other: kotlin.CharSequence?, ignoreCase: kotlin.Boolean): kotlin.Boolean
+
 @kotlin.internal.InlineOnly
 public inline fun kotlin.CharSequence.count(): kotlin.Int
 

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

@@ -268,6 +268,30 @@ public actual fun String.compareTo(other: String, ignoreCase: Boolean = false):
     }
 }
 
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other],
+ * i.e. both char sequences contain the same number of the same characters in the same order.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual infix fun CharSequence?.contentEquals(other: CharSequence?): Boolean = contentEqualsImpl(other)
+
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other], optionally ignoring case difference.
+ *
+ * @param ignoreCase `true` to ignore character case when comparing contents.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual fun CharSequence?.contentEquals(other: CharSequence?, ignoreCase: Boolean): Boolean {
+    return if (ignoreCase)
+        this.contentEqualsIgnoreCaseImpl(other)
+    else
+        this.contentEqualsImpl(other)
+}
+
 
 private val STRING_CASE_INSENSITIVE_ORDER = Comparator<String> { a, b -> a.compareTo(b, ignoreCase = true) }
 

libraries/stdlib/jvm/src/kotlin/text/StringsJVM.kt

@@ -544,8 +544,8 @@ public actual fun String.compareTo(other: String, ignoreCase: Boolean = false):
 /**
  * Returns `true` if this string is equal to the contents of the specified [CharSequence], `false` otherwise.
  *
- * Unlike the overload that accepts an argument of type [StringBuffer],
- * this function does not compare this string and the specified [CharSequence] in a synchronized block.
+ * Note that if the [CharSequence] argument is a [StringBuffer] then the comparison may be performed in a synchronized block
+ * that acquires that [StringBuffer]'s monitor.
  */
 @kotlin.internal.InlineOnly
 public inline fun String.contentEquals(charSequence: CharSequence): Boolean = (this as java.lang.String).contentEquals(charSequence)
@@ -559,6 +559,41 @@ public inline fun String.contentEquals(charSequence: CharSequence): Boolean = (t
 @kotlin.internal.InlineOnly
 public inline fun String.contentEquals(stringBuilder: StringBuffer): Boolean = (this as java.lang.String).contentEquals(stringBuilder)
 
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other],
+ * i.e. both char sequences contain the same number of the same characters in the same order.
+ *
+ * If this [CharSequence] is a [String] and [other] is not `null`
+ * then this function behaves the same as [String.contentEquals].
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual infix fun CharSequence?.contentEquals(other: CharSequence?): Boolean {
+    return if (this is String && other != null)
+        contentEquals(other)
+    else
+        contentEqualsImpl(other)
+}
+
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other], optionally ignoring case difference.
+ *
+ * If this [CharSequence] is a [String], [other] is not `null` and [ignoreCase] is `false`
+ * then this function behaves the same as [String.contentEquals].
+ *
+ * @param ignoreCase `true` to ignore character case when comparing contents.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual fun CharSequence?.contentEquals(other: CharSequence?, ignoreCase: Boolean): Boolean {
+    return if (ignoreCase)
+        contentEqualsIgnoreCaseImpl(other)
+    else
+        contentEquals(other)
+}
+
 /**
  * Returns a canonical representation for this string object.
  */

libraries/stdlib/samples/test/samples/text/strings.kt

@@ -454,4 +454,17 @@ class Strings {
         assertPrints(inputString0.replace('s', 'z'), "Mizzizzippi")
         assertPrints(inputString1.replace("data", "information"), "Insufficient information for meaningful answer.")
     }
+
+    @Sample
+    fun contentEquals() {
+        val stringBuilder = StringBuilder()
+        stringBuilder.append("Kot").append("lin")
+        assertPrints(stringBuilder, "Kotlin")
+        assertTrue(stringBuilder contentEquals "Kotlin")
+
+        stringBuilder.setCharAt(0, 'k')
+        assertPrints(stringBuilder, "kotlin")
+        assertFalse("Kotlin".contentEquals(stringBuilder))
+        assertTrue("Kotlin".contentEquals(stringBuilder, ignoreCase = true))
+    }
 }

libraries/stdlib/src/kotlin/text/Strings.kt

@@ -1378,3 +1378,56 @@ public fun CharSequence.lineSequence(): Sequence<String> = splitToSequence("\r\n
  * The lines returned do not include terminating line separators.
  */
 public fun CharSequence.lines(): List<String> = lineSequence().toList()
+
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other],
+ * i.e. both char sequences contain the same number of the same characters in the same order.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public expect infix fun CharSequence?.contentEquals(other: CharSequence?): Boolean
+
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other], optionally ignoring case difference.
+ *
+ * @param ignoreCase `true` to ignore character case when comparing contents.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public expect fun CharSequence?.contentEquals(other: CharSequence?, ignoreCase: Boolean): Boolean
+
+internal fun CharSequence?.contentEqualsIgnoreCaseImpl(other: CharSequence?): Boolean {
+    if (this is String && other is String) {
+        return this.equals(other, ignoreCase = true)
+    }
+
+    if (this === other) return true
+    if (this == null || other == null || this.length != other.length) return false
+
+    for (i in 0 until length) {
+        if (!this[i].equals(other[i], ignoreCase = true)) {
+            return false
+        }
+    }
+
+    return true
+}
+
+internal fun CharSequence?.contentEqualsImpl(other: CharSequence?): Boolean {
+    if (this is String && other is String) {
+        return this == other
+    }
+
+    if (this === other) return true
+    if (this == null || other == null || this.length != other.length) return false
+
+    for (i in 0 until length) {
+        if (this[i] != other[i]) {
+            return false
+        }
+    }
+
+    return true
+}

libraries/stdlib/test/text/StringTest.kt

@@ -1741,4 +1741,42 @@ ${"    "}
         // Special Casing
         assertEquals("\u0399\u0308\u0301\u0053\u0053", "\u0390\u00DF".uppercase())
     }
+
+    @Test
+    fun contentEquals() = withTwoCharSequenceArgs { arg1, arg2 ->
+        infix fun String?.contentEquals(other: String?): Boolean {
+            return this?.let { arg1(it) } contentEquals other?.let { arg2(it) }
+        }
+
+        assertTrue("" contentEquals "")
+        assertTrue("1" contentEquals "1")
+        assertFalse("12" contentEquals "1")
+        assertFalse("1" contentEquals "12")
+
+        assertTrue("sample" contentEquals "sample")
+        assertFalse("Sample" contentEquals "sample")
+        assertFalse("sample" contentEquals "Sample")
+        assertFalse("sample" contentEquals null)
+        assertFalse(null contentEquals "sample")
+        assertTrue(null contentEquals null)
+    }
+
+    @Test
+    fun contentEqualsIgnoreCase() = withTwoCharSequenceArgs { arg1, arg2 ->
+        fun String.contentEquals(other: String, ignoreCase: Boolean): Boolean {
+            return arg1(this).contentEquals(arg2(other), ignoreCase)
+        }
+
+        assertTrue("".contentEquals("", ignoreCase = false))
+        assertTrue("".contentEquals("", ignoreCase = true))
+        assertTrue("1".contentEquals("1", ignoreCase = false))
+        assertTrue("1".contentEquals("1", ignoreCase = true))
+
+        assertFalse("sample".contentEquals("Sample", ignoreCase = false))
+        assertTrue("sample".contentEquals("Sample", ignoreCase = true))
+        assertFalse("sample".contentEquals(null, ignoreCase = false))
+        assertFalse("sample".contentEquals(null, ignoreCase = true))
+        assertTrue(null.contentEquals(null, ignoreCase = true))
+        assertTrue(null.contentEquals(null, ignoreCase = false))
+    }
 }

libraries/stdlib/wasm/src/kotlin/Text.kt

@@ -425,6 +425,25 @@ actual fun String?.equals(other: String?, ignoreCase: Boolean): Boolean = TODO("
 @SinceKotlin("1.2")
 actual fun String.compareTo(other: String, ignoreCase: Boolean): Int = TODO("Wasm stdlib: Text")
 
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other],
+ * i.e. both char sequences contain the same number of the same characters in the same order.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual infix fun CharSequence?.contentEquals(other: CharSequence?): Boolean = TODO("Wasm stdlib: Text")
+
+/**
+ * Returns `true` if the contents of this char sequence are equal to the contents of the specified [other], optionally ignoring case difference.
+ *
+ * @param ignoreCase `true` to ignore character case when comparing contents.
+ *
+ * @sample samples.text.Strings.contentEquals
+ */
+@SinceKotlin("1.5")
+public actual fun CharSequence?.contentEquals(other: CharSequence?, ignoreCase: Boolean): Boolean = TODO("Wasm stdlib: Text")
+
 
 public actual fun String.startsWith(prefix: String, ignoreCase: Boolean): Boolean = TODO("Wasm stdlib: Text")
 public actual fun String.startsWith(prefix: String, startIndex: Int, ignoreCase: Boolean): Boolean = TODO("Wasm stdlib: Text")

libraries/tools/binary-compatibility-validator/reference-public-api/kotlin-stdlib-runtime-merged.txt

@@ -5261,6 +5261,8 @@ public final class kotlin/text/StringsKt {
 	public static final fun contains (Ljava/lang/CharSequence;Ljava/lang/CharSequence;Z)Z
 	public static synthetic fun contains$default (Ljava/lang/CharSequence;CZILjava/lang/Object;)Z
 	public static synthetic fun contains$default (Ljava/lang/CharSequence;Ljava/lang/CharSequence;ZILjava/lang/Object;)Z
+	public static final fun contentEquals (Ljava/lang/CharSequence;Ljava/lang/CharSequence;)Z
+	public static final fun contentEquals (Ljava/lang/CharSequence;Ljava/lang/CharSequence;Z)Z
 	public static final fun count (Ljava/lang/CharSequence;Lkotlin/jvm/functions/Function1;)I
 	public static final fun decapitalize (Ljava/lang/String;)Ljava/lang/String;
 	public static final fun decapitalize (Ljava/lang/String;Ljava/util/Locale;)Ljava/lang/String;