From: ForthNet@willett.pgh.pa.us (ForthNet articles from GEnie)
Newsgroups: comp.lang.forth
Subject: Environmental Queries
Date: 25 Dec 92 10:09:00 GMT
Organization: EIEI-U

Category 10,  Topic 33
Message 17        Sat Dec 12, 1992
B.RODRIGUEZ2 [Brad]          at 17:27 EST
 
During the second public review period of ANS Forth, the TC has
 satisfactorily addressed -- or at least convinced me to
 postpone -- most of my concerns.  But although some aspects of
 ENVIRONMENT? were clarified, its operation remains unchanged.
 My reply to the TC's response follows:
 ----------------------------------------------------------------

Re. Pp.3-4: S" should be interpretive in CORE
    Pp.5-6: ENVIRONMENT? should take text from the input stream

I do NOT accept the Committee's decision.  I do not feel that the
 committee has adequately addressed my concern, or has justified
 its decision on technical or compatibility grounds.

The Committee's argument seems to be: "This is only a problem for
 cross compilers.  We are not addressing cross compilers.
 Therefore, this is not a problem."

The Committee has indicated that cross compilers _will_ be
 addressed in a future edition of the standard.  Your reply states
 that "...the TC considers it highly desirable to address this
 issue [cross-compilers]."  If we can identify a problem _now_ that
 will plague the next edition of ANS Forth, why not fix it _now_?

Your rationale note A.6.1.1345 makes clear that ENVIRONMENT? can
 only be portably used in user-defined words.  But the committee
 has not yet taken a stand on whether execution of user-defined
 words will be allowed or necessary in a cross-compiler
 environment!  And, by your own statement, the Committee "...would
 be remiss in undertaking such a task without prior public
 announcement, and without having solicited specific input from
 vendors of cross-compilers."

Enshrining this usage of ENVIRONMENT? will, in effect, mandate
 one of the major decisions which pertain to cross-compilers -- a
 decision which should be reserved until cross-compilers are
 properly deliberated.

At no time has the Technical Committee indicated why it is
 necessary for ENVIRONMENT? to take a string argument from the
 stack.  No technical justification has been offered.
 ENVIRONMENT? is a new word, so there is no question of
 compatibility with previous versions.

ENVIRONMENT? is also risky in that its portable usage is not
 obvious.  Many ANS Forth users, failing to note section
 A.6.1.1345, will surely employ interpretive S" in their
 "portable" Forth code.

The proposed word ENVIRONMENTAL is technically superior, in that
 its portable use is obvious, and is compatible with Forth cross-
 compilers.

The time to fix this problem is now, before a troublesome and
 potentially incompatible practice has been established.  If a
 problem can be foreseen, and simply fixed, to refuse to
 acknowledge or correct the problem is negligent.

----------------------------------------------------------------
 I'm posting this for further discussion.  It is my fear that
 ANS Forth will be made forever impractical for metacompilers;
 so far, the TC has not been reassuring.

Brad Rodriguez
 B.RODRIGUEZ2 on GEnie   |   bradford@maccs.dcss.mcmaster.ca
 So many projects....so little time.

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