Add flags check for specials

Author: Sara Alemanno

library/src-3.x/dotty/internal/StringContextMacro.scala

@@ -544,12 +544,18 @@ object StringContextMacro {
      *  @return reports an error if precision or width is specified for '%' or
      *  if precision is specified for end of line
      */
-    def checkSpecials(partIndex : Int, conversionChar : Char, hasPrecision : Boolean, precision : Int, hasWidth : Boolean, width : Int) = conversionChar match {
+    def checkSpecials(partIndex : Int, conversionChar : Char, hasPrecision : Boolean, precision : Int, hasWidth : Boolean, width : Int, flags : List[(Char, Int)]) = conversionChar match {
       case 'n' => {
         checkNotAllowedParameter(hasPrecision, partIndex, precision, "precision")
         checkNotAllowedParameter(hasWidth, partIndex, width, "width")
+        val notAllowedFlagOnCondition = for (flag <- List('-', '#', '+', ' ', '0', ',', '(')) yield (flag, true, "flags not allowed")
+        checkUniqueFlags(partIndex, flags, notAllowedFlagOnCondition : _*)
+      }
+      case '%' => {
+        checkNotAllowedParameter(hasPrecision, partIndex, precision, "precision")
+        val notAllowedFlagOnCondition = for (flag <- List('#', '+', ' ', '0', ',', '(')) yield (flag, true, "Illegal flag '" + flag + "'")
+        checkFlags(partIndex, flags, notAllowedFlagOnCondition : _*)
       }
-      case '%' => checkNotAllowedParameter(hasPrecision, partIndex, precision, "precision")
       case _ => // OK
     }
 
@@ -588,7 +594,7 @@ object StringContextMacro {
         case 'e' | 'E' |'f' | 'g' | 'G' | 'a' | 'A' => checkFloatingPointConversion(partIndex, conversionChar, flags, hasPrecision, precision)
         case 't' | 'T' => checkTimeConversion(partIndex, part, conversion, flags, hasPrecision, precision)
         case 'b' | 'B' | 'h' | 'H' | 'S' | 's' => checkGeneralConversion(partIndex, argType, conversionChar, flags)
-        case 'n' | '%' => checkSpecials(partIndex, conversionChar, hasPrecision, precision, hasWidth, width)
+        case 'n' | '%' => checkSpecials(partIndex, conversionChar, hasPrecision, precision, hasWidth, width, flags)
         case illegal => reporter.partError("illegal conversion character '" + illegal + "'", partIndex, conversion)
       }
 

tests/run-macros/f-interpolator-neg/Tests_2.scala

@@ -54,6 +54,9 @@ object Test {
         (true, 0, 1, 3, "only use '(' for BigInt conversions to o, x, X")))
       assertEquals(foo"$f%,(a", List((true, 0, 1, 1, "',' not allowed for a, A"), (true, 0, 1, 2, "'(' not allowed for a, A")))
       assertEquals(foo"$t%#+ 0,(tT", List((true, 0, 1, 1, "Only '-' allowed for date/time conversions")))
+      assertEquals(foo"%-#+ 0,(n", List((true, 0, 0, 1, "flags not allowed")))
+      assertEquals(foo"%#+ 0,(%", List((true, 0, 0, 1, "Illegal flag '#'"), (true, 0, 0, 2, "Illegal flag '+'"),
+        (true, 0, 0, 3, "Illegal flag ' '"), (true, 0, 0, 4, "Illegal flag '0'"), (true, 0, 0, 5, "Illegal flag ','"), (true, 0, 0, 6, "Illegal flag '('")))
     }
 
     def badPrecisions(c : Char, d : Int, f : Double, t : java.util.Date) = {

tests/run-macros/f-interpolator-tests.check

@@ -78,5 +78,6 @@ am
 08/31/82
 1982-08-31
 the percentage is 100 %
-we have a line separator now %n and now, we are on the next line
+we have a line separator now 
+and now, we are on the next line
 a b b

tests/run-macros/f-interpolator-tests.scala

@@ -187,7 +187,7 @@ object Test {
   def specificLiteralsTests = {
     def percentArgsTest = println(f"the percentage is 100 %%")
 
-    def lineSeparatorArgs = println(f"we have a line separator now %%n and now, we are on the next line")
+    def lineSeparatorArgs = println(f"we have a line separator now %nand now, we are on the next line")
 
     def nothingTest = println(f"we have nothing")