Introduce Common readln() and readlnOrNull() top-level functions #KT-48456

kotlin-native/backend.native/tests/.gitattributes

@@ -0,0 +1,2 @@
+runtime/basic/readln*CR*.in binary
+runtime/basic/readln*CR*.out binary

kotlin-native/backend.native/tests/build.gradle

@@ -727,6 +727,61 @@ standaloneTest("hello2") {
    source = "runtime/basic/hello2.kt"
 }
 
+standaloneTest("readlnOrNull_empty") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readlnOrNull_empty.kt"
+}
+
+standaloneTest("readln_empty") {
+    useTestData = true
+    outputChecker = { s -> s.contains("ReadAfterEOFException") }
+    expectedExitStatusChecker = { it != 0 }
+    source = "runtime/basic/readln_empty.kt"
+}
+
+standaloneTest("readln_alone_CR") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_alone_CR.kt"
+}
+
+standaloneTest("readln_empty_new_line") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_empty_new_line.kt"
+}
+
+standaloneTest("readln_multiline") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_multiline.kt"
+}
+
+standaloneTest("readln_CR_and_CRLF") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_CR_and_CRLF.kt"
+}
+
+standaloneTest("readln_long_line") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_long_line.kt"
+}
+
+standaloneTest("readln_cyrillic") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_cyrillic.kt"
+}
+
+standaloneTest("readln_multiple_empty_new_lines") {
+    useGoldenData = true
+    useTestData = true
+    source = "runtime/basic/readln_multiple_empty_new_lines.kt"
+}
+
 task hello3(type: KonanLocalTest) {
     useGoldenData = true
     source = "runtime/basic/hello3.kt"

kotlin-native/backend.native/tests/runtime/basic/readlnOrNull_empty.kt

@@ -0,0 +1,8 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+fun main() {
+    print("${readlnOrNull()}/${readlnOrNull()}/${readlnOrNull()}")
+}

kotlin-native/backend.native/tests/runtime/basic/readlnOrNull_empty.out

@@ -0,0 +1 @@
+null/null/null

kotlin-native/backend.native/tests/runtime/basic/readln_CR_and_CRLF.in

@@ -0,0 +1,2 @@
+aaaaaa
bbb
+c

kotlin-native/backend.native/tests/runtime/basic/readln_CR_and_CRLF.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_CR_and_CRLF.out

@@ -0,0 +1 @@
+aaaaaa
bbb

kotlin-native/backend.native/tests/runtime/basic/readln_alone_CR.in

@@ -0,0 +1 @@
+

kotlin-native/backend.native/tests/runtime/basic/readln_alone_CR.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_alone_CR.out

@@ -0,0 +1 @@
+

kotlin-native/backend.native/tests/runtime/basic/readln_cyrillic.in

@@ -0,0 +1 @@
+Привет!

kotlin-native/backend.native/tests/runtime/basic/readln_cyrillic.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_cyrillic.out

@@ -0,0 +1 @@
+Привет!

kotlin-native/backend.native/tests/runtime/basic/readln_empty.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    readln()
+}

kotlin-native/backend.native/tests/runtime/basic/readln_empty_new_line.in

@@ -0,0 +1 @@
+

kotlin-native/backend.native/tests/runtime/basic/readln_empty_new_line.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_long_line.in

@@ -0,0 +1 @@
+A very long line of input with length of more than initial buffer size

kotlin-native/backend.native/tests/runtime/basic/readln_long_line.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_long_line.out

@@ -0,0 +1 @@
+A very long line of input with length of more than initial buffer size

kotlin-native/backend.native/tests/runtime/basic/readln_multiline.in

@@ -0,0 +1,3 @@
+Hello World
+Second line
+Third line

kotlin-native/backend.native/tests/runtime/basic/readln_multiline.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print(readln())
+}

kotlin-native/backend.native/tests/runtime/basic/readln_multiline.out

@@ -0,0 +1 @@
+Hello World

kotlin-native/backend.native/tests/runtime/basic/readln_multiple_empty_new_lines.in

@@ -0,0 +1,4 @@
+first
+second
+
+

kotlin-native/backend.native/tests/runtime/basic/readln_multiple_empty_new_lines.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.
+ */
+
+fun main() {
+    print("${readln()}/${readln()}/${readln()}/${readln()}/${readlnOrNull()}")
+}

kotlin-native/backend.native/tests/runtime/basic/readln_multiple_empty_new_lines.out

@@ -0,0 +1 @@
+first/second///null

kotlin-native/runtime/src/main/cpp/Console.cpp

@@ -13,6 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include <cstdio>
+
 #include "KAssert.h"
 #include "Memory.h"
 #include "Natives.h"
@@ -67,4 +69,35 @@ OBJ_GETTER0(Kotlin_io_Console_readLine) {
     RETURN_RESULT_OF(CreateStringFromCString, data);
 }
 
+OBJ_GETTER0(Kotlin_io_Console_readlnOrNull) {
+    KStdVector<char> data;
+    data.reserve(16);
+    bool isEOF = false;
+    bool isError = false;
+    {
+        kotlin::ThreadStateGuard guard(kotlin::ThreadState::kNative);
+        while (true) {
+            int result = fgetc(stdin);
+
+            if (result == EOF || result == '\n') {
+                isEOF = (result == EOF);
+                isError = (ferror(stdin) != 0);
+                break;
+            }
+
+            data.push_back(result);
+        }
+    }
+    if (isError) {
+        ThrowIllegalStateException();
+    }
+    if (!isEOF && !data.empty() && data.back() == '\r') { // CRLF
+        data.pop_back();
+    }
+    if (data.empty() && isEOF) {
+        RETURN_OBJ(nullptr);
+    }
+    RETURN_RESULT_OF(StringFromUtf8Buffer, data.data(), data.size());
+}
+
 } // extern "C"

kotlin-native/runtime/src/main/kotlin/kotlin/io/Console.kt

@@ -29,6 +29,29 @@ public actual fun println(message: Any?) {
 @GCUnsafeCall("Kotlin_io_Console_println0")
 public actual external fun println()
 
+/**
+ * Reads a line of input from the standard input stream and returns it,
+ * or throws a [RuntimeException] if EOF has already been reached when [readln] is called.
+ *
+ * LF or CRLF is treated as the line terminator. Line terminator is not included in the returned string.
+ *
+ * The input is interpreted as UTF-8. Invalid bytes are replaced by the replacement character '\uFFFD'.
+ */
+@SinceKotlin("1.6")
+public actual fun readln(): String = readlnOrNull() ?: throw ReadAfterEOFException("EOF has already been reached")
+
+/**
+ * Reads a line of input from the standard input stream and returns it,
+ * or return `null` if EOF has already been reached when [readlnOrNull] is called.
+ *
+ * LF or CRLF is treated as the line terminator. Line terminator is not included in the returned string.
+ *
+ * The input is interpreted as UTF-8. Invalid bytes are replaced by the replacement character '\uFFFD'.
+ */
+@SinceKotlin("1.6")
+@GCUnsafeCall("Kotlin_io_Console_readlnOrNull")
+public actual external fun readlnOrNull(): String?
+
 /**
  * Reads a line of input from the standard input stream.
  *

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

@@ -2,4 +2,10 @@ public fun print(message: kotlin.Any?): kotlin.Unit
 
 public fun println(): kotlin.Unit
 
-public fun println(message: kotlin.Any?): kotlin.Unit
+public fun println(message: kotlin.Any?): kotlin.Unit
+
+@kotlin.SinceKotlin(version = "1.6")
+public fun readln(): kotlin.String
+
+@kotlin.SinceKotlin(version = "1.6")
+public fun readlnOrNull(): kotlin.String?

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

@@ -2,4 +2,10 @@ public fun print(message: kotlin.Any?): kotlin.Unit
 
 public fun println(): kotlin.Unit
 
-public fun println(message: kotlin.Any?): kotlin.Unit
+public fun println(message: kotlin.Any?): kotlin.Unit
+
+@kotlin.SinceKotlin(version = "1.6")
+public fun readln(): kotlin.String
+
+@kotlin.SinceKotlin(version = "1.6")
+public fun readlnOrNull(): kotlin.String?

libraries/stdlib/common/src/kotlin/ioH.kt

@@ -15,5 +15,29 @@ public expect fun println(message: Any?)
 /** Prints the given [message] to the standard output stream. */
 public expect fun print(message: Any?)
 
+/**
+ * Reads a line of input from the standard input stream and returns it,
+ * or throws a [RuntimeException] if EOF has already been reached when [readln] is called.
+ *
+ * LF or CRLF is treated as the line terminator. Line terminator is not included in the returned string.
+ *
+ * Currently this function is not supported in Kotlin/JS and throws [UnsupportedOperationException].
+ */
+@SinceKotlin("1.6")
+public expect fun readln(): String
+
+/**
+ * Reads a line of input from the standard input stream and returns it,
+ * or return `null` if EOF has already been reached when [readlnOrNull] is called.
+ *
+ * LF or CRLF is treated as the line terminator. Line terminator is not included in the returned string.
+ *
+ * Currently this function is not supported in Kotlin/JS and throws [UnsupportedOperationException].
+ */
+@SinceKotlin("1.6")
+public expect fun readlnOrNull(): String?
+
+internal class ReadAfterEOFException(message: String?) : RuntimeException(message)
+
 
 internal expect interface Serializable

libraries/stdlib/js/src/kotlin/console.kt

@@ -104,3 +104,9 @@ public actual fun println(message: Any?) {
 public actual fun print(message: Any?) {
     output.print(message)
 }
+
+@SinceKotlin("1.6")
+public actual fun readln(): String = throw UnsupportedOperationException("readln is not supported in Kotlin/JS")
+
+@SinceKotlin("1.6")
+public actual fun readlnOrNull(): String? = throw UnsupportedOperationException("readlnOrNull is not supported in Kotlin/JS")

libraries/stdlib/jvm/src/kotlin/io/Console.kt

@@ -149,7 +149,7 @@ public actual inline fun println() {
  * The input is decoded using the system default Charset. A [CharacterCodingException] is thrown if input is malformed.
  */
 @SinceKotlin("1.6")
-public fun readln(): String = readlnOrNull() ?: throw ReadAfterEOFException("EOF has already been reached")
+public actual fun readln(): String = readlnOrNull() ?: throw ReadAfterEOFException("EOF has already been reached")
 
 /**
  * Reads a line of input from the standard input stream and returns it,
@@ -160,9 +160,7 @@ public fun readln(): String = readlnOrNull() ?: throw ReadAfterEOFException("EOF
  * The input is decoded using the system default Charset. A [CharacterCodingException] is thrown if input is malformed.
  */
 @SinceKotlin("1.6")
-public fun readlnOrNull(): String? = readLine()
-
-private class ReadAfterEOFException(message: String?) : RuntimeException(message)
+public actual fun readlnOrNull(): String? = readLine()
 
 /**
  * Reads a line of input from the standard input stream.

libraries/stdlib/jvm/test/io/Console.kt

@@ -48,6 +48,20 @@ class ConsoleTest {
         testReadLine("first${linuxLineSeparator}second", listOf("first", "second"))
     }
 
+    @Test
+    fun shouldReadMultipleEmptyLines() {
+        testReadLine(
+            "first${linuxLineSeparator}second${linuxLineSeparator}${linuxLineSeparator}${linuxLineSeparator}",
+            listOf("first", "second", "", "")
+        )
+    }
+
+    @Test
+    fun shouldReadAloneCarriageReturn() {
+        val result = readLines("\r", Charsets.UTF_8)
+        assertEquals(listOf("\r"), result)
+    }
+
     @Test
     fun shouldReadConsecutiveEmptyLines() {
         testReadLine("$linuxLineSeparator$linuxLineSeparator", listOf("", ""))

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

@@ -23,6 +23,12 @@ public actual fun print(message: Any?) {
     println(message)
 }
 
+@SinceKotlin("1.6")
+public actual fun readln(): String = TODO("Wasm stdlib: IO")
+
+@SinceKotlin("1.6")
+public actual fun readlnOrNull(): String? = TODO("Wasm stdlib: IO")
+
 
 internal actual interface Serializable