Opened 5 years ago

Last modified 2 years ago

#349 new defect

ANSI lacuna: interaction between SHARPSIGN-LEFT-PARENTHENSIS and backquote splice operator

Reported by: Evenson Not Org Owned by:
Priority: major Milestone: 1.6.0
Component: interpreter Version: 1.3.0-dev
Keywords: ansi lacunae Cc:
Parent Tickets:

Description

Faré notes in <http://article.gmane.org/gmane.lisp.armedbear.devel/3101>:

What should this form read as?
`#5(1 , <at> `(2 3))

ECL, LispWorks and fare-quasiquote agree on #(1 2 3 2 3)
allegro, ccl, clisp, sbcl return the arguably conformant #(1 2 3 2 3 2 3 2 3)
abcl, cmucl, gcl, xcl all return the arguably completely buggy #(1 2 3)

Subtickets

Change History (8)

comment:1 Changed 5 years ago by Evenson Not Org

Keywords: ansi lacunae added
Summary: Incorret interaction between SHARPSIGN-LEFT-PARENTHENSIS and backquote splice operatorANSI lacuna: interaction between SHARPSIGN-LEFT-PARENTHENSIS and backquote splice operator

comment:2 Changed 5 years ago by Evenson Not Org

Pascal notes

#5( anything ) should return a vector of dimension 5 in any case.

Furthermore,  

    "If the number of objects supplied before the closing ) is less than
     the unsigned decimal integer but greater than zero, the last object
     is used to fill all remaining elements of the  vector."

so they're all wrong, and expected result should be: #5(1 2 3 3 3)

Basically, 

            `#5(1 ,@`(2 3))

should take:

            `#(1 ,@`(2 3))

which all implementation agree that's read as:

            #(1 2 3)

and extends the last element to give:

            #5(1 2 3 3 3)


Now, since the reader macro is #\`, we should really apply #\` rules,
but the only rule for vectors is:

   * `#(x1 x2 x3 ... xn) may be interpreted to mean
     (apply #'vector `(x1 x2 x3 ... xn)).

so one could argue that there's no rule for `#n(…), and therefore it's
not a conforming form anyways.

If #n(…) is collapsed to #(…) then the abcl result is correct, as per
the above rule.

comment:3 Changed 5 years ago by Evenson Not Org

Try for sbcl

`#6(1 ,@`(2 3 4))
==>
#(1 2 3 4 2 3 4 2 3 4 2 3 4 2 3 4)

is surely bad…

Last edited 5 years ago by Evenson Not Org (previous) (diff)

comment:4 Changed 5 years ago by Evenson Not Org

Milestone: 1.3.02.0

Ticket retargeted after milestone closed

comment:5 Changed 5 years ago by Evenson Not Org

Milestone: 2.02.0.0

Milestone renamed

comment:6 Changed 5 years ago by Evenson Not Org

Milestone: 2.0.01.4.0

comment:7 Changed 3 years ago by Evenson Not Org

Milestone: 1.4.01.5.0

Ticket retargeted after milestone closed

comment:8 Changed 2 years ago by Evenson Not Org

Milestone: 1.5.01.6.0

Ticket retargeted after milestone closed

Note: See TracTickets for help on using tickets.