SI-8266 Deprecate octal escapes in f-interpolator

Also turns the f-interpolator into a migration
assistant by suggesting alternatives for the
standard escapes.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/library/scala/StringContext.scala b/src/library/scala/StringContext.scala
index 2d79452c5d..cd928a2b61 100644
--- a/src/library/scala/StringContext.scala
+++ b/src/library/scala/StringContext.scala
@@ -172,8 +172,8 @@ object StringContext {
    *  @param  str   The offending string
    *  @param  idx   The index of the offending backslash character in `str`.
    */
-  class InvalidEscapeException(str: String, idx: Int)
-    extends IllegalArgumentException("invalid escape character at index "+idx+" in \""+str+"\"")
+  class InvalidEscapeException(str: String, @deprecatedName('idx) val index: Int)
+    extends IllegalArgumentException("invalid escape character at index "+index+" in \""+str+"\"")
 
   /** Expands standard Scala escape sequences in a string.
    *  Escape sequences are:
@@ -184,7 +184,11 @@ object StringContext {
    *  @param  str  A string that may contain escape sequences
    *  @return The string with all escape sequences expanded.
    */
-  def treatEscapes(str: String): String = {
+  def treatEscapes(str: String): String = treatEscapes0(str, strict = false)
+
+  def processEscapes(str: String): String = treatEscapes0(str, strict = true)
+
+  private def treatEscapes0(str: String, strict: Boolean): String = {
     lazy val bldr = new java.lang.StringBuilder
     val len = str.length
     var start = 0
@@ -201,6 +205,7 @@ object StringContext {
         idx += 1
         if (idx >= len) throw new InvalidEscapeException(str, cur)
         if ('0' <= str(idx) && str(idx) <= '7') {
+          if (strict) throw new InvalidEscapeException(str, cur)
           val leadch = str(idx)
           var oct = leadch - '0'
           idx += 1