WIP Account for inferredness in type error

Blaisorblade · Blaisorblade · commit a583a246f3ec · 2018-08-17T18:07:24.000+02:00
diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala
@@ -44,10 +44,14 @@ object Checking {
         ctx.error(ex"missing type parameter(s) for $arg", arg.pos)
       }
     }
-    for ((arg, which, bound) <- ctx.boundsViolations(args, boundss, instantiate))
-      ctx.error(
+    for ((arg, which, bound) <- ctx.boundsViolations(args, boundss, instantiate)) {
+      if (arg.pos.isZeroExtent)
+        ctx.error(
           DoesNotConformToBound(arg.tpe, which, bound)(err),
           arg.pos.focus)
+      else
+        ctx.error(hl"inferred type ${arg.tpe} violates $which bound $bound", arg.pos.focus)
+    }
   }
 
   /** Check that type arguments `args` conform to corresponding bounds in `tl`

Original file line number	Diff line number	Diff line change
`@@ -44,10 +44,14 @@ object Checking {`
`44`	`44`	`ctx.error(ex"missing type parameter(s) for $arg", arg.pos)`
`45`	`45`	`}`
`46`	`46`	`}`
`47`		`- for ((arg, which, bound) <- ctx.boundsViolations(args, boundss, instantiate))`
`48`		`- ctx.error(`
	`47`	`+ for ((arg, which, bound) <- ctx.boundsViolations(args, boundss, instantiate)) {`
	`48`	`+ if (arg.pos.isZeroExtent)`
	`49`	`+ ctx.error(`
`49`	`50`	`DoesNotConformToBound(arg.tpe, which, bound)(err),`
`50`	`51`	`arg.pos.focus)`
	`52`	`+ else`
	`53`	`+ ctx.error(hl"inferred type ${arg.tpe} violates $which bound $bound", arg.pos.focus)`
	`54`	`+ }`
`51`	`55`	`}`
`52`	`56`
`53`	`57`	/** Check that type arguments `args` conform to corresponding bounds in `tl`