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Started by Phil Nelson
Tue, 30 Apr 1991 00:44
Questions/comments about POSIX bc (P1003.2/D11)
Author: Phil Nelson
Date: Tue, 30 Apr 1991 00:44
Date: Tue, 30 Apr 1991 00:44
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Submitted-by: phil@cs.wwu.edu (Phil Nelson)
Hello,
I've been working on an implementation of bc and have been
using the POSIX draft as a definition of the language. In
working on the program, I have found several problems with
the draft. I have P1003.2/D11 and any line number references
are from that draft. The following are what I consider to be
problems. If I am wrong, please help me understand what the
committee intended.
1) The character '-' "shall" be recognized as both the token
ADD_OP and the token '-'.
lines: 1587, 1670, 1737, 1738, 1749-1751
2) Lines 1642-1644 are
parameter_list : LETTER
| define_list ',' LETTER
I presume it should be
parameter_list : LETTER
| parameter_list ',' LETTER
3) Lines 1836-1838 state "A whole array passed as an argument
shall be specified by the array name followed by empty square
brackets."
a) I find no provision in the grammar in the definition of the
parameter list define a parameter as an array. (See lines
1642-1644.)
b) No provision is made in the grammar for the specification of
an array in the actual function call. (See 1657-1659.)
I am interested in knowing if these have been noticed before and if
there are changes to the draft.
Phil Nelson
phil@cs.wwu.edu
Volume-Number: Volume 23, Number 53
Re: Questions/comments about POSIX bc (P1003.2/D11)
Author: Bob Lenk
Date: Tue, 07 May 1991 00:29
Date: Tue, 07 May 1991 00:29
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Submitted-by: rml@hpfcdc.fc.hp.com (Bob Lenk)
In article <131021@uunet.UU.NET>, phil@cs.wwu.edu (Phil Nelson) writes:
> 1) The character '-' "shall" be recognized as both the token
> ADD_OP and the token '-'.
> lines: 1587, 1670, 1737, 1738, 1749-1751
The intention is that the minus character can be recognized as either
unary minus or as a binary operator (with the same precedence as
the other ADD_OP, binary +). The lexical specification is indeed
ambiguous and incorrect.
> 2) Lines 1642-1644 are
> parameter_list : LETTER
> | define_list ',' LETTER
> I presume it should be
> parameter_list : LETTER
> | parameter_list ',' LETTER
This was an error in preparation of Draft 10. The presumption is
correct.
> 3) Lines 1836-1838 state "A whole array passed as an argument
> shall be specified by the array name followed by empty square
> brackets."
> a) I find no provision in the grammar in the definition of the
> parameter list define a parameter as an array. (See lines
> 1642-1644.)
> b) No provision is made in the grammar for the specification of
> an array in the actual function call. (See 1657-1659.)
This was also an error in the preparation of Draft 10. The sentence in
question was intended to be deleted. A reference to this feature in
the grammar was deleted. This feature has been documented but not
implemented in all historical versions of bc I have encountered.
I was the terchnical editor for bc during the ballot that produced Draft
10. The three errors noted above are mine. It is interesting that they
have gone unnoticed for this long (Draft 10 was distributed last summer,
and a full ballot recirculation has completed).
I am forwarding this message to the chair of P1003.2, effectively as
ballot comments. Note that they do not include a resolution for problem
(1). Those comments and this posting are made strictly as an
individual.
Bob Lenk
rml@fc.hp.com
{uunet,hplabs}!fc.hp.com!rml
Volume-Number: Volume 23, Number 58
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