Opened 5 years ago

Closed 5 years ago

#388 closed defect (fixed)

Specify what `display` does with circular lists

Reported by: cowan Owned by: cowan
Priority: major Milestone:
Component: WG1 - Core Keywords:
Cc:

Description

Currently we don't specify what display does with circular lists. Should it generate labels like write, or loop like write-simple, or leave it unspecified?

Change History (5)

comment:1 Changed 5 years ago by alexshinn

We don't specify anything wrt display for anything
other than string and character inputs. It would be
very out of place to specify anything for circular
structures without also specifying all structures,
which would be very difficult to get implementations
to agree to.

comment:2 Changed 5 years ago by cowan

If you compare write, write-simple, and display, you'll see that write defines behavior for strings, symbols, characters, and shared structure. Write-simple says it is the same as write except on shared structure. However, display defines behavior for strings, symbols, and characters only. Adding a definition for shared-list behavior is therefore appropriate. We don't need to define behavior for everything else.

I haven't done a full test, but most Schemes seem to use write-simple behavior.

comment:3 Changed 5 years ago by cowan

  • Status changed from new to decided

WG1 decided to adopt write behavior, printing datum labels as required.

comment:4 Changed 5 years ago by cowan

  • Owner changed from alexshinn to cowan
  • Status changed from decided to writing

comment:5 Changed 5 years ago by cowan

  • Resolution set to fixed
  • Status changed from writing to closed
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