Introduce the new ♢ modifier and don't wrap spaces by default (#2001)

* Add diamond symbol to docs

* Get all tests to pass

* Replace usages of · with space

* Ignore unsafe wraps

interop/kotlin-metadata/src/main/kotlin/com/squareup/kotlinpoet/metadata/specs/KotlinPoetMetadataSpecs.kt

@@ -251,7 +251,7 @@ public fun KmPackage.toFileSpec(
     .build()
 }
 
-private const val NOT_IMPLEMENTED = "throw·NotImplementedError(\"Stub!\")"
+private const val NOT_IMPLEMENTED = "throw NotImplementedError(\"Stub!\")"
 
 private fun KmClass.toTypeSpec(
   classInspector: ClassInspector?,

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/CodeBlock.kt

@@ -50,9 +50,10 @@ import kotlin.reflect.KClass
  *    importable, e.g. it's a top-level function or a property declared inside an object, the import
  *    will be resolved if possible. Arguments for members must be of type [MemberName].
  *  * `%%` emits a percent sign.
- *  * `·` emits a space that never wraps. KotlinPoet prefers to wrap lines longer than 100 columns.
- *    It does this by replacing normal spaces with a newline and indent. Note that spaces in strings
- *    are never wrapped.
+ *  * `♢` emits a space or a newline, depending on its position on the line. This prefers to wrap
+ *    lines before 100 columns. It does this by replacing normal spaces with a newline and indent.
+ *    Note that spaces in strings are never wrapped.
+ *  * `·` emits a space that never wraps. Equivalent to the regular space (` `).
  *  * `⇥` increases the indentation level.
  *  * `⇤` decreases the indentation level.
  *  * `«` begins a statement. For multiline statements, every line after the first line is
@@ -430,7 +431,7 @@ public class CodeBlock private constructor(
           break
         }
       }
-      return "$this·{\n"
+      return "$this {\n"
     }
 
     /**
@@ -439,7 +440,7 @@ public class CodeBlock private constructor(
      */
     public fun nextControlFlow(controlFlow: String, vararg args: Any?): Builder = apply {
       unindent()
-      add("}·$controlFlow·{\n", *args)
+      add("} $controlFlow {\n", *args)
       indent()
     }
 

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/CodeWriter.kt

@@ -587,7 +587,7 @@ internal class CodeWriter(
       if (!first) {
         if ((kdoc || comment) && trailingNewline) {
           emitIndentation()
-          out.appendNonWrapping(if (kdoc) " *" else "//")
+          out.append(if (kdoc) " *" else "//")
         }
         out.newline()
         trailingNewline = true
@@ -606,9 +606,9 @@ internal class CodeWriter(
       if (trailingNewline) {
         emitIndentation()
         if (kdoc) {
-          out.appendNonWrapping(" * ")
+          out.append(" * ")
         } else if (comment) {
-          out.appendNonWrapping("// ")
+          out.append("// ")
         }
       }
 
@@ -627,7 +627,7 @@ internal class CodeWriter(
 
   private fun emitIndentation() {
     for (j in 0..<indentLevel) {
-      out.appendNonWrapping(indent)
+      out.append(indent)
     }
   }
 

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/FileSpec.kt

@@ -164,7 +164,7 @@ public class FileSpec private constructor(
     val escapedPackageName = packageName.escapeSegmentsIfNecessary()
 
     if (escapedPackageName.isNotEmpty()) {
-      codeWriter.emitCode("package·%L\n", escapedPackageName)
+      codeWriter.emitCode("package %L\n", escapedPackageName)
       codeWriter.emit("\n")
     }
 
@@ -186,7 +186,7 @@ public class FileSpec private constructor(
 
     if (imports.isNotEmpty()) {
       for (import in imports) {
-        codeWriter.emitCode("import·%L", import)
+        codeWriter.emitCode("import %L", import)
         codeWriter.emit("\n")
       }
       codeWriter.emit("\n")
@@ -290,7 +290,7 @@ public class FileSpec private constructor(
 
     /** Adds a file-site comment. This is prefixed to the start of the file and different from [addBodyComment]. */
     public fun addFileComment(format: String, vararg args: Any): Builder = apply {
-      comment.add(format.replace(' ', '·'), *args)
+      comment.add(format, *args)
     }
 
     @Deprecated(
@@ -480,7 +480,7 @@ public class FileSpec private constructor(
       check(isScript) {
         "addBodyComment() is only allowed in script files"
       }
-      body.add("//·${format.replace(' ', '·')}\n", *args)
+      body.add("// $format\n", *args)
     }
 
     /**

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/FunSpec.kt

@@ -100,7 +100,7 @@ public class FunSpec private constructor(
     codeWriter.emitModifiers(modifiers, implicitModifiers)
 
     if (!isConstructor && !name.isAccessor) {
-      codeWriter.emitCode("fun·")
+      codeWriter.emitCode("fun ")
     }
 
     if (typeVariables.isNotEmpty()) {
@@ -120,7 +120,7 @@ public class FunSpec private constructor(
     if (asExpressionBody != null) {
       codeWriter.emitCode(CodeBlock.of(" = %L", asExpressionBody), ensureTrailingNewline = true)
     } else if (!isEmptySetter) {
-      codeWriter.emitCode("·{\n")
+      codeWriter.emitCode(" {\n")
       codeWriter.indent()
       codeWriter.emitCode(body.returnsWithoutLinebreak(), ensureTrailingNewline = true)
       codeWriter.unindent()
@@ -505,7 +505,7 @@ public class FunSpec private constructor(
     }
 
     public fun addComment(format: String, vararg args: Any): Builder = apply {
-      body.add("//·${format.replace(' ', '·')}\n", *args)
+      body.add("// $format\n", *args)
     }
 
     /**

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/Import.kt

@@ -23,7 +23,7 @@ public data class Import internal constructor(
   private val importString = buildString {
     append(qualifiedName.escapeSegmentsIfNecessary())
     if (alias != null) {
-      append("·as·${alias.escapeIfNecessary()}")
+      append(" as ${alias.escapeIfNecessary()}")
     }
   }
 

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/LambdaTypeName.kt

@@ -62,10 +62,10 @@ public class LambdaTypeName private constructor(
     }
 
     if (isSuspending) {
-      out.emit("suspend·")
+      out.emit("suspend ")
     }
 
-    out.emitContextReceivers(contextReceivers, suffix = "·")
+    out.emitContextReceivers(contextReceivers, suffix = " ")
 
     receiver?.let {
       if (it.isAnnotated) {
@@ -76,7 +76,7 @@ public class LambdaTypeName private constructor(
     }
 
     parameters.emit(out)
-    out.emitCode(if (returnType is LambdaTypeName) "·->·(%T)" else "·->·%T", returnType)
+    out.emitCode(if (returnType is LambdaTypeName) " -> (%T)" else " -> %T", returnType)
 
     if (isNullable) {
       out.emit(")")

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/LineWrapper.kt

@@ -52,8 +52,8 @@ internal class LineWrapper(
     var pos = 0
     while (pos < s.length) {
       when (s[pos]) {
-        ' ' -> {
-          // Each space starts a new empty segment.
+        '♢' -> {
+          // Each wrapping space starts a new empty segment.
           this.indentLevel = indentLevel
           this.linePrefix = linePrefix
           segments += ""
@@ -66,7 +66,7 @@ internal class LineWrapper(
           pos++
         }
 
-        '·' -> {
+        ' ', '·' -> {
           // Render · as a non-breaking space.
           segments[segments.size - 1] += " "
           pos++
@@ -105,8 +105,6 @@ internal class LineWrapper(
   }
 
   private fun emitCurrentLine() {
-    foldUnsafeBreaks()
-
     var start = 0
     var columnCount = segments[0].length
 
@@ -150,26 +148,7 @@ internal class LineWrapper(
     }
   }
 
-  /**
-   * Any segment that starts with '+' or '-' can't have a break preceding it. Combine it with the
-   * preceding segment. Note that this doesn't apply to the first segment.
-   */
-  private fun foldUnsafeBreaks() {
-    var i = 1
-    while (i < segments.size) {
-      val segment = segments[i]
-      if (UNSAFE_LINE_START.matches(segment)) {
-        segments[i - 1] = segments[i - 1] + " " + segments[i]
-        segments.removeAt(i)
-        if (i > 1) i--
-      } else {
-        i++
-      }
-    }
-  }
-
   companion object {
-    private val UNSAFE_LINE_START = Regex("\\s*[-+].*")
-    private val SPECIAL_CHARACTERS = " \n·".toCharArray()
+    private val SPECIAL_CHARACTERS = " \n·♢".toCharArray()
   }
 }

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/ParameterSpec.kt

@@ -59,7 +59,7 @@ public class ParameterSpec private constructor(
     codeWriter.emitAnnotations(annotations, inlineAnnotations)
     codeWriter.emitModifiers(modifiers)
     if (name.isNotEmpty()) codeWriter.emitCode("%N", this)
-    if (name.isNotEmpty() && includeType) codeWriter.emitCode(":·")
+    if (name.isNotEmpty() && includeType) codeWriter.emitCode(": ")
     if (includeType) codeWriter.emitCode("%T", type)
     emitDefaultValue(codeWriter)
   }

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/ParameterizedTypeName.kt

@@ -86,7 +86,7 @@ public class ParameterizedTypeName internal constructor(
     if (typeArguments.isNotEmpty()) {
       out.emit("<")
       typeArguments.forEachIndexed { index, parameter ->
-        if (index > 0) out.emit(",·")
+        if (index > 0) out.emit(", ")
         parameter.emitAnnotations(out)
         parameter.emit(out)
         parameter.emitNullable(out)

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/PropertySpec.kt

@@ -79,10 +79,10 @@ public class PropertySpec private constructor(
     codeWriter.emitContextReceivers(contextReceiverTypes, suffix = "\n")
     codeWriter.emitAnnotations(annotations, inlineAnnotations)
     codeWriter.emitModifiers(propertyModifiers, implicitModifiers)
-    codeWriter.emitCode(if (mutable) "var·" else "val·")
+    codeWriter.emitCode(if (mutable) "var " else "val ")
     if (typeVariables.isNotEmpty()) {
       codeWriter.emitTypeVariables(typeVariables)
-      codeWriter.emit(" ")
+      codeWriter.emit("♢")
     }
     if (receiverType != null) {
       if (receiverType is LambdaTypeName) {
@@ -91,12 +91,12 @@ public class PropertySpec private constructor(
         codeWriter.emitCode("%T.", receiverType)
       }
     }
-    codeWriter.emitCode("%N: %T", this, type)
+    codeWriter.emitCode("%N:♢%T", this, type)
     if (withInitializer && initializer != null) {
       if (delegated) {
-        codeWriter.emit(" by ")
+        codeWriter.emit("♢by♢")
       } else {
-        codeWriter.emitCode(" = ")
+        codeWriter.emitCode("♢=♢")
       }
       val initializerFormat = if (initializer.hasStatements()) "%L" else "«%L»"
       codeWriter.emitCode(

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/TypeSpec.kt

@@ -236,7 +236,7 @@ public class TypeSpec private constructor(
         }
 
         if (superTypes.isNotEmpty()) {
-          val separator = if (wrapSupertypes) ",\n    " else ", "
+          val separator = if (wrapSupertypes) ",\n    " else ",♢"
           codeWriter.emitCode(superTypes.joinToCode(separator = separator, prefix = " : "))
         }
 

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/Util.kt

@@ -353,7 +353,7 @@ private fun String.escapeIfNotJavaIdentifier(): String {
       ) &&
     !alreadyEscaped()
   ) {
-    "`$this`".replace(' ', '·')
+    "`$this`"
   } else {
     this
   }

kotlinpoet/src/commonMain/kotlin/com/squareup/kotlinpoet/WildcardTypeName.kt

@@ -46,9 +46,9 @@ public class WildcardTypeName private constructor(
 
   override fun emit(out: CodeWriter): CodeWriter {
     return when {
-      inTypes.size == 1 -> out.emitCode("in·%T", inTypes[0])
+      inTypes.size == 1 -> out.emitCode("in %T", inTypes[0])
       outTypes == STAR.outTypes -> out.emit("*")
-      else -> out.emitCode("out·%T", outTypes[0])
+      else -> out.emitCode("out %T", outTypes[0])
     }
   }
 

kotlinpoet/src/commonTest/kotlin/com/squareup/kotlinpoet/CodeBlockTest.kt

@@ -562,10 +562,8 @@ class CodeBlockTest {
       |package com.squareup.tacos
       |
       |public fun test() {
-      |  if ("Very long string that would wrap the line " ==
-      |      "Very long string that would wrap the line ") {
-      |  } else if ("Long string that would wrap the line 2 " ==
-      |      "Long string that would wrap the line 2 ") {
+      |  if ("Very long string that would wrap the line " == "Very long string that would wrap the line ") {
+      |  } else if ("Long string that would wrap the line 2 " == "Long string that would wrap the line 2 ") {
       |  }
       |}
       |

kotlinpoet/src/commonTest/kotlin/com/squareup/kotlinpoet/KotlinPoetTest.kt

@@ -1016,8 +1016,7 @@ class KotlinPoetTest {
       |
       |import kotlin.String
       |
-      |public
-      |    fun functionWithAPrettyLongNameThatWouldCauseWrapping(parameterWithALongNameThatWouldAlsoCauseWrapping: String) {
+      |public fun functionWithAPrettyLongNameThatWouldCauseWrapping(parameterWithALongNameThatWouldAlsoCauseWrapping: String) {
       |}
       |
       """.trimMargin(),
@@ -1103,13 +1102,11 @@ class KotlinPoetTest {
       |import kotlin.String
       |
       |/**
-      | * Builder class for Foo. Allows creating instances of Foo by initializing a subset of their fields,
-      | * following the Builder pattern.
+      | * Builder class for Foo. Allows creating instances of Foo by initializing a subset of their fields, following the Builder pattern.
       | */
       |public class Builder {
       |  /**
-      |   * The description for the choice, e.g. "Currently unavailable due to high demand. Please try
-      |   * later." May be null.
+      |   * The description for the choice, e.g. "Currently unavailable due to high demand. Please try later." May be null.
       |   */
       |  public fun summary_text(summary_text: String?): Builder {
       |    this.summary_text = summary_text