Regex: Turn CharSequence into Strings upon entry in our implementation.

sjrd · sjrd · commit 85b9d6fc4353 · 2021-06-10T18:54:09.000+02:00
Since we have to convert the input `CharSequence`s to `String`s
anyway to be able to give them to `js.RegExp`, it is better to do
that upon entry into our implementation. We can force the
`toString()`s to be at the call site, which can then be inlined and
removed when the arguments are already Strings, which should be the
vast majority of use cases.
diff --git a/javalib/src/main/scala/java/util/regex/Matcher.scala b/javalib/src/main/scala/java/util/regex/Matcher.scala
@@ -19,7 +19,7 @@ import scala.annotation.switch
 import scala.scalajs.js
 
 final class Matcher private[regex] (
-    private var pattern0: Pattern, private var input0: CharSequence)
+    private var pattern0: Pattern, private var input0: String)
     extends AnyRef with MatchResult {
 
   import Matcher._
@@ -29,7 +29,7 @@ final class Matcher private[regex] (
   // Region configuration (updated by reset() and region())
   private var regionStart0 = 0
   private var regionEnd0 = input0.length()
-  private var inputstr = input0.toString()
+  private var inputstr = input0
 
   // Match result (updated by successful matches)
   private var position: Int = 0 // within `inputstr`, not `input0`
@@ -158,12 +158,13 @@ final class Matcher private[regex] (
   def reset(): Matcher = {
     regionStart0 = 0
     regionEnd0 = input0.length()
-    inputstr = input0.toString()
+    inputstr = input0
     resetMatch()
   }
 
+  @inline // `input` is almost certainly a String at call site
   def reset(input: CharSequence): Matcher = {
-    input0 = input
+    input0 = input.toString()
     reset()
   }
 
@@ -245,7 +246,7 @@ final class Matcher private[regex] (
   def region(start: Int, end: Int): Matcher = {
     regionStart0 = start
     regionEnd0 = end
-    inputstr = input0.subSequence(regionStart0, regionEnd0).toString
+    inputstr = input0.substring(start, end)
     resetMatch()
   }
 
diff --git a/javalib/src/main/scala/java/util/regex/Pattern.scala b/javalib/src/main/scala/java/util/regex/Pattern.scala
@@ -136,15 +136,19 @@ final class Pattern private[regex] (
 
   override def toString(): String = pattern()
 
+  @inline // `input` is almost certainly a String at call site
   def matcher(input: CharSequence): Matcher =
-    new Matcher(this, input)
+    new Matcher(this, input.toString())
 
+  @inline // `input` is almost certainly a String at call site
   def split(input: CharSequence): Array[String] =
     split(input, 0)
 
-  def split(input: CharSequence, limit: Int): Array[String] = {
-    val inputStr = input.toString
+  @inline // `input` is almost certainly a String at call site
+  def split(input: CharSequence, limit: Int): Array[String] =
+    splitString(input.toString(), limit)
 
+  private def splitString(inputStr: String, limit: Int): Array[String] = {
     // If the input string is empty, always return Array("") - #987, #2592
     if (inputStr == "") {
       Array("")
@@ -207,7 +211,11 @@ object Pattern {
   def compile(regex: String): Pattern =
     compile(regex, 0)
 
+  @inline // `input` is almost certainly a String at call site
   def matches(regex: String, input: CharSequence): Boolean =
+    matchesString(regex, input.toString())
+
+  private def matchesString(regex: String, input: String): Boolean =
     compile(regex).matcher(input).matches()
 
   def quote(s: String): String = {
