Move Regex pattern definitions to a separate file in preparation for SN

scalafmt-core/jvm/src/main/scala/org/scalafmt/internal/RegexCompat.scala

@@ -0,0 +1,94 @@
+package org.scalafmt.internal
+
+import java.util.regex.Pattern
+
+private[scalafmt] object RegexCompat {
+
+  @inline
+  val trailingSpace = Pattern.compile("\\h++$", Pattern.MULTILINE)
+
+  // "slc" stands for single-line comment
+  @inline
+  val slcLine = Pattern.compile("^/\\/\\/*+\\h*+(.*?)\\h*+$")
+
+  @inline
+  val slcDelim = Pattern.compile("\\h++")
+
+  // "mlc" stands for multi-line comment
+  @inline
+  val mlcHeader = Pattern.compile("^/\\*\\h*+(?:\n\\h*+[*]*+\\h*+)?")
+
+  @inline
+  val mlcLineDelim = Pattern.compile("\\h*+\n\\h*+[*]*+\\h*+")
+
+  @inline
+  val mlcParagraphEnd = Pattern.compile("[.:!?=]$")
+
+  @inline
+  val mlcParagraphBeg = Pattern.compile("^(?:[-*@=]|\\d++[.:])")
+
+  @inline
+  private val leadingAsteriskSpace = Pattern.compile("(?<=\n)\\h*+(?=[*][^*])")
+
+  @inline
+  val docstringLine = Pattern
+    .compile("^(?:\\h*+\\*)?(\\h*+)(.*?)\\h*+$", Pattern.MULTILINE)
+
+  @inline
+  private val emptyLines = "\\h*+(\n\\h*+\\*?\\h*+)*"
+
+  @inline
+  val emptyDocstring = Pattern.compile(s"^/\\*\\*$emptyLines\\*/$$")
+
+  @inline
+  val onelineDocstring = {
+    val oneline = "[^*\n\\h](?:[^\n]*[^\n\\h])?"
+    Pattern.compile(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/$$")
+  }
+
+  @inline
+  val docstringLeadingSpace = Pattern.compile("^\\h++")
+
+  @inline
+  def compileStripMarginPattern(pipe: Char) = Pattern
+    .compile(s"(?<=\n)\\h*+(?=\\$pipe)")
+
+  @inline
+  def compileStripMarginPatternWithLineContent(pipe: Char) = Pattern
+    .compile(s"\n(\\h*+\\$pipe)?([^\n]*+)")
+
+  @inline
+  val stripMarginPattern = compileStripMarginPattern('|')
+
+  @inline
+  val stripMarginPatternWithLineContent =
+    compileStripMarginPatternWithLineContent('|')
+
+  @inline
+  private val leadingPipeSpace = compileStripMarginPattern('|')
+
+  @inline
+  private def getStripMarginPattern(pipe: Char) =
+    if (pipe == '|') leadingPipeSpace else compileStripMarginPattern(pipe)
+
+  @inline
+  def replaceAllStripMargin(
+      text: String,
+      spaces: String,
+      pipe: Char,
+  ): String =
+    getStripMarginPattern(pipe).matcher(text).replaceAll(spaces)
+
+  @inline
+  def replaceAllLeadingAsterisk(
+      trimmed: String,
+      spaces: String,
+  ): String = leadingAsteriskSpace.matcher(trimmed).replaceAll(spaces)
+
+  // Replaces baseText.split("(?={beforeText})")
+  @inline
+  def splitByBeforeTextMatching(
+      baseText: String,
+      beforeText: String,
+  ): Array[String] = baseText.split(s"(?=$beforeText)")
+}

scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatWriter.scala

@@ -5,6 +5,7 @@ import org.scalafmt.Error
 import org.scalafmt.Formatted
 import org.scalafmt.Scalafmt
 import org.scalafmt.config.{Case => _, _}
+import org.scalafmt.internal.RegexCompat._
 import org.scalafmt.rewrite.RedundantBraces
 import org.scalafmt.util.LiteralOps
 import org.scalafmt.util.TokenOps._
@@ -583,7 +584,7 @@ class FormatWriter(formatOps: FormatOps) {
         }
         tupleOpt.fold(text) { case (pipe, indent) =>
           val spaces = getIndentation(indent)
-          getStripMarginPattern(pipe).matcher(text).replaceAll(spaces)
+          RegexCompat.replaceAllStripMargin(text, spaces, pipe)
         }
       }
 
@@ -794,7 +795,7 @@ class FormatWriter(formatOps: FormatOps) {
             terminateMlc(curlen, lines)
           } else {
             val trimmed = removeTrailingWhiteSpace(text)
-            sb.append(leadingAsteriskSpace.matcher(trimmed).replaceAll(spaces))
+            sb.append(RegexCompat.replaceAllLeadingAsterisk(trimmed, spaces))
           }
 
         private def appendLineBreak(): Unit = startNewLine(spaces).append('*')
@@ -1905,42 +1906,12 @@ object FormatWriter {
   private def getIndentation(len: Int): String =
     if (len < indentations.length) indentations(len) else " " * len
 
-  private val trailingSpace = Pattern.compile("\\h++$", Pattern.MULTILINE)
   private def removeTrailingWhiteSpace(str: String): String = trailingSpace
     .matcher(str).replaceAll("")
 
   private def splitAsIterator(regex: Pattern)(value: String): Iterator[String] =
     regex.splitAsStream(value).iterator().asScala
 
-  // "slc" stands for single-line comment
-  private val slcDelim = Pattern.compile("\\h++")
-  // "mlc" stands for multi-line comment
-  private val mlcHeader = Pattern.compile("^/\\*\\h*+(?:\n\\h*+[*]*+\\h*+)?")
-  private val mlcLineDelim = Pattern.compile("\\h*+\n\\h*+[*]*+\\h*+")
-  private val mlcParagraphEnd = Pattern.compile("[.:!?=]$")
-  private val mlcParagraphBeg = Pattern.compile("^(?:[-*@=]|\\d++[.:])")
-
-  private val leadingAsteriskSpace = Pattern.compile("(?<=\n)\\h*+(?=[*][^*])")
-  private val docstringLine = Pattern
-    .compile("^(?:\\h*+\\*)?(\\h*+)(.*?)\\h*+$", Pattern.MULTILINE)
-  private val emptyLines = "\\h*+(\n\\h*+\\*?\\h*+)*"
-  private val emptyDocstring = Pattern.compile(s"^/\\*\\*$emptyLines\\*/$$")
-  private val onelineDocstring = {
-    val oneline = "[^*\n\\h](?:[^\n]*[^\n\\h])?"
-    Pattern.compile(s"^/\\*\\*$emptyLines($oneline)$emptyLines\\*/$$")
-  }
-  private val docstringLeadingSpace = Pattern.compile("^\\h++")
-
-  @inline
-  private def getStripMarginPattern(pipe: Char) =
-    if (pipe == '|') leadingPipeSpace else compileStripMarginPattern(pipe)
-
-  @inline
-  private def compileStripMarginPattern(pipe: Char) = Pattern
-    .compile(s"(?<=\n)\\h*+(?=\\$pipe)")
-
-  private val leadingPipeSpace = compileStripMarginPattern('|')
-
   /** [[https://dotty.epfl.ch/docs/reference/other-new-features/indentation.html#the-end-marker]]
     */
   private def getEndMarkerLabel(tree: Tree): String = tree match {

scalafmt-core/shared/src/main/scala/org/scalafmt/internal/State.scala

@@ -9,8 +9,6 @@ import org.scalafmt.util.TreeOps._
 import scala.meta._
 import scala.meta.tokens.Token
 
-import java.util.regex.Pattern
-
 import scala.annotation.tailrec
 
 /** A partial formatting solution up to splits.length number of tokens.
@@ -371,16 +369,9 @@ object State {
   }
 
   @inline
-  private def compileStripMarginPattern(pipe: Char) = Pattern
-    .compile(s"\n(\\h*+\\$pipe)?([^\n]*+)")
-
-  @inline
-  private def getStripMarginPattern(pipe: Char) =
-    if (pipe == '|') pipeStripMarginPattern else compileStripMarginPattern(pipe)
-
-  private val pipeStripMarginPattern = compileStripMarginPattern('|')
-
-  private val slcLine = Pattern.compile("^/\\/\\/*+\\h*+(.*?)\\h*+$")
+  private def getStripMarginPatternWithLineContent(pipe: Char) =
+    if (pipe == '|') RegexCompat.stripMarginPatternWithLineContent
+    else RegexCompat.compileStripMarginPatternWithLineContent(pipe)
 
   def getColumns(ft: FormatToken, indent: Int, column: Int)(implicit
       style: ScalafmtConfig,
@@ -390,7 +381,7 @@ object State {
     if (firstNL < 0) {
       val syntaxLen =
         if (column != 0 && ft.right.is[Token.Comment]) {
-          val asSlc = State.slcLine.matcher(syntax)
+          val asSlc = RegexCompat.slcLine.matcher(syntax)
           if (asSlc.matches()) 3 + asSlc.end(1) - asSlc.start(1)
           else syntax.length
         } else syntax.length
@@ -457,7 +448,7 @@ object State {
       adjustMargin: Int => Int,
       firstLength: Int,
   ): (Int, Int) = {
-    val matcher = getStripMarginPattern(pipe).matcher(syntax)
+    val matcher = getStripMarginPatternWithLineContent(pipe).matcher(syntax)
     matcher.region(firstNL, syntax.length)
     if (!matcher.find()) (firstLength, firstLength)
     else {

scalafmt-tests/shared/src/test/scala/org/scalafmt/cli/FileTestOps.scala

@@ -1,6 +1,7 @@
 package org.scalafmt.cli
 
 import org.scalafmt.config.ScalafmtConfig
+import org.scalafmt.internal.RegexCompat
 import org.scalafmt.sysops.AbsoluteFile
 import org.scalafmt.sysops.FileOps
 
@@ -15,7 +16,7 @@ object FileTestOps {
     */
   def string2dir(layout: String): AbsoluteFile = {
     val root = AbsoluteFile(Files.createTempDirectory("root"))
-    layout.split("(?=\n/)").foreach { row =>
+    RegexCompat.splitByBeforeTextMatching(layout, "\n/").foreach { row =>
       val path :: contents :: Nil = row.stripPrefix("\n").split("\n", 2).toList
       val file = root / path.stripPrefix("/")
       file.parent.mkdirs()