Rename 'foo' function to 'simple' in flow docs (Kotlin#2078)

The name 'foo' might be hard to get for novice developers. It is really hard to find a "meaningful" name for all examples in the docs, so this is simply a consistent solution. The alternative is to something like "simpleFlow", but adding a "Flow" suffix to the name implicitly condones Hungarian notation, which is not aligned with Kotlin coding style.

kotlinx-coroutines-core/jvm/test/guide/example-flow-01.kt

@@ -5,8 +5,8 @@
 // This file was automatically generated from flow.md by Knit tool. Do not edit.
 package kotlinx.coroutines.guide.exampleFlow01
 
-fun foo(): List<Int> = listOf(1, 2, 3)
+fun simple(): List<Int> = listOf(1, 2, 3)
 
 fun main() {
- foo().forEach { value -> println(value) } 
+ simple().forEach { value -> println(value) } 
 }

kotlinx-coroutines-core/jvm/test/guide/example-flow-02.kt

@@ -5,13 +5,13 @@
 // This file was automatically generated from flow.md by Knit tool. Do not edit.
 package kotlinx.coroutines.guide.exampleFlow02
 
-fun foo(): Sequence<Int> = sequence { // sequence builder
+fun simple(): Sequence<Int> = sequence { // sequence builder
  for (i in 1..3) {
  Thread.sleep(100) // pretend we are computing it
  yield(i) // yield next value
  }
 }
 
 fun main() {
- foo().forEach { value -> println(value) } 
+ simple().forEach { value -> println(value) } 
 }

kotlinx-coroutines-core/jvm/test/guide/example-flow-03.kt

@@ -7,11 +7,11 @@ package kotlinx.coroutines.guide.exampleFlow03
 
 import kotlinx.coroutines.* 
 
-suspend fun foo(): List<Int> {
+suspend fun simple(): List<Int> {
  delay(1000) // pretend we are doing something asynchronous here
  return listOf(1, 2, 3)
 }
 
 fun main() = runBlocking<Unit> {
- foo().forEach { value -> println(value) } 
+ simple().forEach { value -> println(value) } 
 }

kotlinx-coroutines-core/jvm/test/guide/example-flow-04.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow04
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow { // flow builder
+fun simple(): Flow<Int> = flow { // flow builder
  for (i in 1..3) {
  delay(100) // pretend we are doing something useful here
  emit(i) // emit next value
@@ -24,5 +24,5 @@ fun main() = runBlocking<Unit> {
  }
  }
  // Collect the flow
- foo().collect { value -> println(value) } 
+ simple().collect { value -> println(value) } 
 }

kotlinx-coroutines-core/jvm/test/guide/example-flow-05.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow05
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow { 
+fun simple(): Flow<Int> = flow { 
  println("Flow started")
  for (i in 1..3) {
  delay(100)
@@ -17,8 +17,8 @@ fun foo(): Flow<Int> = flow {
 }
 
 fun main() = runBlocking<Unit> {
- println("Calling foo...")
- val flow = foo()
+ println("Calling simple function...")
+ val flow = simple()
  println("Calling collect...")
  flow.collect { value -> println(value) } 
  println("Calling collect again...")

kotlinx-coroutines-core/jvm/test/guide/example-flow-06.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow06
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow { 
+fun simple(): Flow<Int> = flow { 
  for (i in 1..3) {
  delay(100) 
  println("Emitting $i")
@@ -18,7 +18,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> {
  withTimeoutOrNull(250) { // Timeout after 250ms 
- foo().collect { value -> println(value) } 
+ simple().collect { value -> println(value) } 
  }
  println("Done")
 }

kotlinx-coroutines-core/jvm/test/guide/example-flow-13.kt

@@ -10,13 +10,13 @@ import kotlinx.coroutines.flow.*
 
 fun log(msg: String) = println("[${Thread.currentThread().name}] $msg")
 
-fun foo(): Flow<Int> = flow {
- log("Started foo flow")
+fun simple(): Flow<Int> = flow {
+ log("Started simple flow")
  for (i in 1..3) {
  emit(i)
  }
 } 
 
 fun main() = runBlocking<Unit> {
- foo().collect { value -> log("Collected $value") } 
+ simple().collect { value -> log("Collected $value") } 
 } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-14.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow14
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  // The WRONG way to change context for CPU-consuming code in flow builder
  kotlinx.coroutines.withContext(Dispatchers.Default) {
  for (i in 1..3) {
@@ -19,5 +19,5 @@ fun foo(): Flow<Int> = flow {
 }
 
 fun main() = runBlocking<Unit> {
- foo().collect { value -> println(value) } 
+ simple().collect { value -> println(value) } 
 } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-15.kt

@@ -10,7 +10,7 @@ import kotlinx.coroutines.flow.*
 
 fun log(msg: String) = println("[${Thread.currentThread().name}] $msg")
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  Thread.sleep(100) // pretend we are computing it in CPU-consuming way
  log("Emitting $i")
@@ -19,7 +19,7 @@ fun foo(): Flow<Int> = flow {
 }.flowOn(Dispatchers.Default) // RIGHT way to change context for CPU-consuming code in flow builder
 
 fun main() = runBlocking<Unit> {
- foo().collect { value ->
+ simple().collect { value ->
  log("Collected $value") 
  } 
 } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-16.kt

@@ -9,7 +9,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 import kotlin.system.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  delay(100) // pretend we are asynchronously waiting 100 ms
  emit(i) // emit next value
@@ -18,7 +18,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> { 
  val time = measureTimeMillis {
- foo().collect { value -> 
+ simple().collect { value -> 
  delay(300) // pretend we are processing it for 300 ms
  println(value) 
  } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-17.kt

@@ -9,7 +9,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 import kotlin.system.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  delay(100) // pretend we are asynchronously waiting 100 ms
  emit(i) // emit next value
@@ -18,7 +18,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> { 
  val time = measureTimeMillis {
- foo()
+ simple()
  .buffer() // buffer emissions, don't wait
  .collect { value -> 
  delay(300) // pretend we are processing it for 300 ms

kotlinx-coroutines-core/jvm/test/guide/example-flow-18.kt

@@ -9,7 +9,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 import kotlin.system.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  delay(100) // pretend we are asynchronously waiting 100 ms
  emit(i) // emit next value
@@ -18,7 +18,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> { 
  val time = measureTimeMillis {
- foo()
+ simple()
  .conflate() // conflate emissions, don't process each one
  .collect { value -> 
  delay(300) // pretend we are processing it for 300 ms

kotlinx-coroutines-core/jvm/test/guide/example-flow-19.kt

@@ -9,7 +9,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 import kotlin.system.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  delay(100) // pretend we are asynchronously waiting 100 ms
  emit(i) // emit next value
@@ -18,7 +18,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> { 
  val time = measureTimeMillis {
- foo()
+ simple()
  .collectLatest { value -> // cancel & restart on the latest value
  println("Collecting $value") 
  delay(300) // pretend we are processing it for 300 ms

kotlinx-coroutines-core/jvm/test/guide/example-flow-26.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow26
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  println("Emitting $i")
  emit(i) // emit next value
@@ -17,7 +17,7 @@ fun foo(): Flow<Int> = flow {
 
 fun main() = runBlocking<Unit> {
  try {
- foo().collect { value -> 
+ simple().collect { value -> 
  println(value)
  check(value <= 1) { "Collected $value" }
  }

kotlinx-coroutines-core/jvm/test/guide/example-flow-27.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow27
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<String> = 
+fun simple(): Flow<String> = 
  flow {
  for (i in 1..3) {
  println("Emitting $i")
@@ -22,7 +22,7 @@ fun foo(): Flow<String> =
 
 fun main() = runBlocking<Unit> {
  try {
- foo().collect { value -> println(value) }
+ simple().collect { value -> println(value) }
  } catch (e: Throwable) {
  println("Caught $e")
  } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-28.kt

@@ -8,7 +8,7 @@ package kotlinx.coroutines.guide.exampleFlow28
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<String> = 
+fun simple(): Flow<String> = 
  flow {
  for (i in 1..3) {
  println("Emitting $i")
@@ -21,7 +21,7 @@ fun foo(): Flow<String> =
  }
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .catch { e -> emit("Caught $e") } // emit on exception
  .collect { value -> println(value) }
 } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-29.kt

@@ -8,15 +8,15 @@ package kotlinx.coroutines.guide.exampleFlow29
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  println("Emitting $i")
  emit(i)
  }
 }
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .catch { e -> println("Caught $e") } // does not catch downstream exceptions
  .collect { value ->
  check(value <= 1) { "Collected $value" } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-30.kt

@@ -8,15 +8,15 @@ package kotlinx.coroutines.guide.exampleFlow30
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  for (i in 1..3) {
  println("Emitting $i")
  emit(i)
  }
 }
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .onEach { value ->
  check(value <= 1) { "Collected $value" } 
  println(value) 

kotlinx-coroutines-core/jvm/test/guide/example-flow-31.kt

@@ -8,11 +8,11 @@ package kotlinx.coroutines.guide.exampleFlow31
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = (1..3).asFlow()
+fun simple(): Flow<Int> = (1..3).asFlow()
 
 fun main() = runBlocking<Unit> {
  try {
- foo().collect { value -> println(value) }
+ simple().collect { value -> println(value) }
  } finally {
  println("Done")
  }

kotlinx-coroutines-core/jvm/test/guide/example-flow-32.kt

@@ -8,10 +8,10 @@ package kotlinx.coroutines.guide.exampleFlow32
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = (1..3).asFlow()
+fun simple(): Flow<Int> = (1..3).asFlow()
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .onCompletion { println("Done") }
  .collect { value -> println(value) }
 } 

kotlinx-coroutines-core/jvm/test/guide/example-flow-33.kt

@@ -8,13 +8,13 @@ package kotlinx.coroutines.guide.exampleFlow33
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = flow {
+fun simple(): Flow<Int> = flow {
  emit(1)
  throw RuntimeException()
 }
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .onCompletion { cause -> if (cause != null) println("Flow completed exceptionally") }
  .catch { cause -> println("Caught exception") }
  .collect { value -> println(value) }

kotlinx-coroutines-core/jvm/test/guide/example-flow-34.kt

@@ -8,10 +8,10 @@ package kotlinx.coroutines.guide.exampleFlow34
 import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.*
 
-fun foo(): Flow<Int> = (1..3).asFlow()
+fun simple(): Flow<Int> = (1..3).asFlow()
 
 fun main() = runBlocking<Unit> {
- foo()
+ simple()
  .onCompletion { cause -> println("Flow completed with $cause") }
  .collect { value ->
  check(value <= 1) { "Collected $value" } 

kotlinx-coroutines-core/jvm/test/guide/test/FlowGuideTest.kt

@@ -50,7 +50,7 @@ class FlowGuideTest {
  @Test
  fun testExampleFlow05() {
  test("ExampleFlow05") { kotlinx.coroutines.guide.exampleFlow05.main() }.verifyLines(
- "Calling foo...",
+ "Calling simple function...",
  "Calling collect...",
  "Flow started",
  "1",
@@ -139,7 +139,7 @@ class FlowGuideTest {
  @Test
  fun testExampleFlow13() {
  test("ExampleFlow13") { kotlinx.coroutines.guide.exampleFlow13.main() }.verifyLinesFlexibleThread(
- "[main @coroutine#1] Started foo flow",
+ "[main @coroutine#1] Started simple flow",
  "[main @coroutine#1] Collected 1",
  "[main @coroutine#1] Collected 2",
  "[main @coroutine#1] Collected 3"