[MLton] Re: [MLton-commit] r6295

[Matthew Fluet]

On Wed, 2 Jan 2008, Vesa Karvonen wrote:
> Reverted a change made in revision 6046.
>
> Tycon.newString and Tycon.fromString have the same effect except that
> Tycon.newString leaves the printName of the tycon unset while
> Tycon.fromString sets the given string as the printName for type tycon.
>
> In revision 6046, the code was changed to use Tycon.newString.  An effect
> of that change was that the names of many (more?) tycons in compiler
> output (e.g. output produced by show-basis) included a generated suffix.
> Although such names are more precise in some sense, the generated suffices
> make the tycon names less readable to a programmer.

... but more readable to (and precise for) a developer trying to debug the 
output of elaboration.  I've no objection to reverting the change, but 
that was the reason for it.

> This commit reverts the code to use Tycon.fromString.  Regression tests
> seem to pass and the code from the bug report that was fixed by revision
> 6046 also seems to compile correctly.

As you note, the only difference between the two Tycon.new* functions is 
how they set the printName, which in turn only affects IL output; the 
tycons still have unique identities as seen by the compiler.