SI-8092 More verify for f-interpolator

Attempt to verify the nooks and crannies of the format string.

Allows all syntax in the javadoc, including arg indexes. If the
specifier after an arg has an index that doesn't refer to the arg,
a warning is issued and the missing `%s` is prepended (just as
for a part with a leading `%n`).

Other enhancements include detecting that a `Formattable` wasn't
supplied to `%#s`.

Error messages attempt to be pithy but descriptive.

1 files changed, 115 insertions, 16 deletions

diff --git a/test/files/neg/stringinterpolation_macro-neg.check b/test/files/neg/stringinterpolation_macro-neg.check
index 457f497f2f..00002f5a4b 100644
--- a/test/files/neg/stringinterpolation_macro-neg.check
+++ b/test/files/neg/stringinterpolation_macro-neg.check
@@ -1,61 +1,61 @@
-stringinterpolation_macro-neg.scala:8: error: too few parts
+stringinterpolation_macro-neg.scala:13: error: there are no parts
   new StringContext().f()
   ^
-stringinterpolation_macro-neg.scala:9: error: too few arguments for interpolated string
+stringinterpolation_macro-neg.scala:14: error: too few arguments for interpolated string
   new StringContext("", " is ", "%2d years old").f(s)
                                                    ^
-stringinterpolation_macro-neg.scala:10: error: too many arguments for interpolated string
+stringinterpolation_macro-neg.scala:15: error: too many arguments for interpolated string
   new StringContext("", " is ", "%2d years old").f(s, d, d)
                                                          ^
-stringinterpolation_macro-neg.scala:11: error: too few arguments for interpolated string
+stringinterpolation_macro-neg.scala:16: error: too few arguments for interpolated string
   new StringContext("", "").f()
                              ^
-stringinterpolation_macro-neg.scala:14: error: type mismatch;
+stringinterpolation_macro-neg.scala:19: error: type mismatch;
  found   : String
  required: Boolean
   f"$s%b"
      ^
-stringinterpolation_macro-neg.scala:15: error: type mismatch;
+stringinterpolation_macro-neg.scala:20: error: type mismatch;
  found   : String
  required: Char
   f"$s%c"
      ^
-stringinterpolation_macro-neg.scala:16: error: type mismatch;
+stringinterpolation_macro-neg.scala:21: error: type mismatch;
  found   : Double
  required: Char
   f"$f%c"
      ^
-stringinterpolation_macro-neg.scala:17: error: type mismatch;
+stringinterpolation_macro-neg.scala:22: error: type mismatch;
  found   : String
  required: Int
   f"$s%x"
      ^
-stringinterpolation_macro-neg.scala:18: error: type mismatch;
+stringinterpolation_macro-neg.scala:23: error: type mismatch;
  found   : Boolean
  required: Int
   f"$b%d"
      ^
-stringinterpolation_macro-neg.scala:19: error: type mismatch;
+stringinterpolation_macro-neg.scala:24: error: type mismatch;
  found   : String
  required: Int
   f"$s%d"
      ^
-stringinterpolation_macro-neg.scala:20: error: type mismatch;
+stringinterpolation_macro-neg.scala:25: error: type mismatch;
  found   : Double
  required: Int
   f"$f%o"
      ^
-stringinterpolation_macro-neg.scala:21: error: type mismatch;
+stringinterpolation_macro-neg.scala:26: error: type mismatch;
  found   : String
  required: Double
   f"$s%e"
      ^
-stringinterpolation_macro-neg.scala:22: error: type mismatch;
+stringinterpolation_macro-neg.scala:27: error: type mismatch;
  found   : Boolean
  required: Double
   f"$b%f"
      ^
-stringinterpolation_macro-neg.scala:27: error: type mismatch;
+stringinterpolation_macro-neg.scala:32: error: type mismatch;
  found   : String
  required: Int
 Note that implicit conversions are not applicable because they are ambiguous:
@@ -64,7 +64,106 @@ Note that implicit conversions are not applicable because they are ambiguous:
  are possible conversion functions from String to Int
     f"$s%d"
        ^
-stringinterpolation_macro-neg.scala:30: error: illegal conversion character
+stringinterpolation_macro-neg.scala:35: error: illegal conversion character 'i'
   f"$s%i"
        ^
-15 errors found
+stringinterpolation_macro-neg.scala:38: error: Illegal flag '+'
+  f"$s%+ 0,(s"
+       ^
+stringinterpolation_macro-neg.scala:38: error: Illegal flag ' '
+  f"$s%+ 0,(s"
+        ^
+stringinterpolation_macro-neg.scala:38: error: Illegal flag '0'
+  f"$s%+ 0,(s"
+         ^
+stringinterpolation_macro-neg.scala:38: error: Illegal flag ','
+  f"$s%+ 0,(s"
+          ^
+stringinterpolation_macro-neg.scala:38: error: Illegal flag '('
+  f"$s%+ 0,(s"
+           ^
+stringinterpolation_macro-neg.scala:39: error: Only '-' allowed for c conversion
+  f"$c%#+ 0,(c"
+       ^
+stringinterpolation_macro-neg.scala:40: error: # not allowed for d conversion
+  f"$d%#d"
+       ^
+stringinterpolation_macro-neg.scala:41: error: ',' only allowed for d conversion of integral types
+  f"$d%,x"
+       ^
+stringinterpolation_macro-neg.scala:42: error: only use '+' for BigInt conversions to o, x, X
+  f"$d%+ (x"
+       ^
+stringinterpolation_macro-neg.scala:42: error: only use ' ' for BigInt conversions to o, x, X
+  f"$d%+ (x"
+        ^
+stringinterpolation_macro-neg.scala:42: error: only use '(' for BigInt conversions to o, x, X
+  f"$d%+ (x"
+         ^
+stringinterpolation_macro-neg.scala:43: error: ',' not allowed for a, A
+  f"$f%,(a"
+       ^
+stringinterpolation_macro-neg.scala:43: error: '(' not allowed for a, A
+  f"$f%,(a"
+        ^
+stringinterpolation_macro-neg.scala:44: error: Only '-' allowed for date/time conversions
+  f"$t%#+ 0,(tT"
+       ^
+stringinterpolation_macro-neg.scala:47: error: precision not allowed
+  f"$c%.2c"
+       ^
+stringinterpolation_macro-neg.scala:48: error: precision not allowed
+  f"$d%.2d"
+       ^
+stringinterpolation_macro-neg.scala:49: error: precision not allowed
+  f"%.2%"
+     ^
+stringinterpolation_macro-neg.scala:50: error: precision not allowed
+  f"%.2n"
+     ^
+stringinterpolation_macro-neg.scala:51: error: precision not allowed
+  f"$f%.2a"
+       ^
+stringinterpolation_macro-neg.scala:52: error: precision not allowed
+  f"$t%.2tT"
+       ^
+stringinterpolation_macro-neg.scala:55: error: No last arg
+  f"%<s"
+     ^
+stringinterpolation_macro-neg.scala:56: error: No last arg
+  f"%<c"
+     ^
+stringinterpolation_macro-neg.scala:57: error: No last arg
+  f"%<tT"
+     ^
+stringinterpolation_macro-neg.scala:58: error: Argument index out of range
+  f"${8}%d ${9}%d%3$$d"
+                  ^
+stringinterpolation_macro-neg.scala:59: error: Argument index out of range
+  f"${8}%d ${9}%d%0$$d"
+                  ^
+stringinterpolation_macro-neg.scala:62: warning: Index is not this arg
+  f"${8}%d ${9}%1$$d"
+                ^
+stringinterpolation_macro-neg.scala:63: warning: Argument index ignored if '<' flag is present
+  f"$s%s $s%s %1$$<s"
+               ^
+stringinterpolation_macro-neg.scala:64: warning: Index is not this arg
+  f"$s%s $s%1$$s"
+            ^
+stringinterpolation_macro-neg.scala:67: error: type mismatch;
+ found   : String
+ required: java.util.Formattable
+  f"$s%#s"
+     ^
+stringinterpolation_macro-neg.scala:70: error: 'G' doesn't seem to be a date or time conversion
+  f"$t%tG"
+        ^
+stringinterpolation_macro-neg.scala:71: error: Date/time conversion must have two characters
+  f"$t%t"
+       ^
+stringinterpolation_macro-neg.scala:72: error: Missing conversion operator in '%10.5'; use %% for literal %, %n for newline
+  f"$s%10.5"
+      ^
+three warnings found
+44 errors found