Cleanup Issue FORMAT-ATSIGN-COLON
- Status
- Passed, jun-87
- Category
- CLARIFICATION
- References
- FORMAT description (p386)
Problem Description
CLtL describes the format op syntax as:
"a format directive consists of a tilde (~), optional prefix parameters separated by commas, optional colon (:) and atsign (@) modifiers, and a single character indicating what kind of directive this is."
CLtL uses :@ fairly consistently throughout without saying whether @: is legal. Is @: allowed?
There is no required ordering between the @ and : modifier.Rationale
This is currently underspecified, and this way of specifying it will cause the least disruption to user code.Current Practice
Most implementations accept these in either order. Some implementations have been known to expect only :@.Adoption Cost
The change to accept either syntax is probably quite trivial.Benefits
Having @: and :@ mean different things would be awkward.Conversion Cost
Existing user code would be unaffected.Aesthetics
Leaving these unordered is slightly simpler conceptually.Discussion
The cleanup committee supports this clarification.Edit History
- Version 1 by Pitman 02/27/87
- Version 2 by cleanup committee 15-Mar-87
- Version 3 by Masinter 15-Mar-87
- Version 4 by Masinter 5-Jun-87