>>>>> "BCW" == Bryan C Warnock <[EMAIL PROTECTED]> writes:
BCW> Keywords
BCW> continue, do, else, elsif, for, foreach, given, goto, grep, if, last,
BCW> map, next, redo, sort, sub, unless, until, when, while
BCW> Basic Constructs
BCW> 1. [ LABEL: ] expr;
BCW> 2. [ LABEL: ] { block } [ continue { block } ]
BCW> 3. << grep | map >> { block } list # Note 1
BCW> 4. sort [ { block } ] list # Note 1
BCW> 5. do { block } # Note 1
i don't consider sort/map/grep blocks to be basic like the others. also
sort/map can take espressions which is a different syntax.
what about eval BLOCK? i think that is being renamed to throw/catch but
it takes a code block too.
BCW> Conditional Statement Modifiers
BCW> 6. [ LABEL: ] expr if expr;
BCW> 7. [ LABEL: ] expr until expr;
^^^^^
unless
BCW> Looping Statement Modifiers
BCW> 8. [ LABEL: ] expr while expr;
BCW> 9. [ LABEL: ] do { block } while expr; # Note 2
i see the note, but that is not special. just a simple expression with a
modifier. now, if the do BLOCK while() were to support loop semantics,
it would be special here.
BCW> 10. [ LABEL: ] expr until expr;
BCW> 11. [ LABEL: ] do { block } until expr; # Note 3
BCW> Iterative Statement Modifiers
BCW> 12. [ LABEL: ] expr for[each] list; # Note 4
BCW> Conditional Block Constructs
BCW> 13. [ LABEL: ] if ( expr ) { block }
BCW> [ [ elsif ( expr ) { block } ] ... ]
BCW> [ else { block } ]
BCW> 14. [ LABEL: ] until ( expr ) { block }
^^^^^
unless (again :-)
BCW> A statement consists of zero or more expressions, followed by an
BCW> optional modifier and its expression, and either a statement
BCW> terminator (';') or a block closure ('}' or EOF).
how do you have multiple expressions in a statement? when you combine
expressions you just get one larger expression.
also perl has statement separators, not terminators. with that
definition you don't need to mention block close or EOF.
BCW> A block consists of zero or more blocks and statements. A file is
BCW> considered a block, delimited by the file boundaries.
BCW> Semantically, I will define a block only in terms of its affect
BCW> on scoping. (Blocks are sometimes referenced by their
BCW> interaction with flow control. However, this definition isn't
BCW> consistent, and I will avoid it.)
a good definition of a BLOCK and its scoping and loop semantics is
needed. the do BLOCK while() controversy is one are that needs clearing
up.
BCW> Flow Control Expressions
BCW> A. goto
BCW> B.
B. was intentionally left blank.
BCW> last
BCW> next
BCW> redo
overall a good idea and thankfully written in english and not
ANSI-speak. a more proper (but not official sanctioned by some
organization) perl specification will be useful. i doubt there will be
multiple implementations like you get with many other languages that
have specs, but it will make it easier to create tests suites, fix bugs,
etc. when we get to exposing various API's it will be very useful to
have clean spec and a document style/format for them (like the PDD).
uri
--
Uri Guttman --------- [EMAIL PROTECTED] ---------- http://www.sysarch.com
SYStems ARCHitecture and Stem Development ------ http://www.stemsystems.com
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