Issue SHARP-O-FOOBAR Writeup

Forum:		Public Review

Issue:		SHARP-O-FOOBAR

References:	Loosemore's public review comment #5

		#b, #o, #x, #r reader syntax 

		  (sections 2.4.8.7 to 2.4.8.10, pages 2-30..2-31)

Category:	CLARIFICATION

Edit history:	21 Dec 1992, Version 1 by Loosemore

Status:         Proposal CONSEQUENCES-UNDEFINED passed (8+2)-1 on 

                letter ballot 93-302.



Problem description:


  Is #ofoobar valid syntax?  In other words, what happens if the

  object following #b, #o, #x, or #r doesn't have the syntax of

  a rational in the given radix?



Proposal (SHARP-O-FOOBAR:CONSEQUENCES-UNDEFINED):


  Clarify that the consequences are undefined if the token following

  #b, #o, #x, or #r does not have the syntax of a rational in the given

  radix.



Rationale:


  At least some implementations signal an error.  Other implementations

  apparently just rebind *READ-BASE* and call READ recursively.



Current practice:


  Lucid, CMU CL, and AKCL all signal an error.  WCL reads #ofoobar

  as the symbol FOOBAR.



Cost to implementors:


  None.



Cost to users:


  None, since the behavior already differs among implementations.



Aesthetics:


  Being explicitly vague is better than being implicitly vague.



Editorial impact:


  Adding one sentence to each of the four referenced sections.



Discussion: