Pretty printing of Absyn in error message does not respect fixity

[JohnReppy]

Version

110.82

Operating System

• All
• Linux
• macOS
• Windows
• Other Unix

OS Version

No response

Processor

Any

Component

Core system

Severity

Cosmetic

Description of the problem

The error message prints '::' as a prefix operator, instead of as an infix operator. This behavior is a regression, since previous versions got it right (see tests/bugs/outputs/bug0027.out for example).

Transcript

Standard ML of New Jersey v110.82 [built: Sat Oct 14 13:08:58 2017]
- fun f [] = 0
=   | f (x::xs) y = 1;
stdIn:1.6-2.20 Error: clauses don't all have same number of patterns
stdIn:1.6-2.20 Error: parameter or result constraints of clauses don't agree [tycon mismatch]
  this clause:      'Z list * 'Y -> 'X
  previous clauses:      'W list -> 'X
  in declaration:
    f = (fn nil => 0
          | (:: <pat>,y) => 1)

Expected Behavior

No response

Steps to Reproduce

fun f [] = 0
    | f (x::xs) y = 1;

Additional Information

No response

Email address

No response

Comments from smlnj-gforge

Original smlnj-gforge bug number 204

Submitted on 2018-05-19 at 14:37:00

Keywords: Pretty printing

[dmacqueen]

Fixed in 110.99.3. The problem was in ElabData/syntax/ppabsyn.sml, function ppDconPat, where in the APPpat case, the argument of the APPpat was not "stripped" to remove MARKpat (or CONSTRAINEDpat). Added/moved the required stripping functions (headStripExp and headStripPat) to ElabData/syntax/absynutil.sml and cleaned up a couple of debugging/printing flags by moving them to ElabData/main/edcontrol.*.