Pike-devel May 2008

pike-devel@lists.lysator.liu.se

10 participants
55 discussions

Process.run
by Peter Bortas (nu med mindre Opera) ＠ Pike (-) developers forum 15 Jul '08

15 Jul '08

I just checked in a Process.run() in 7.7: http://pike.ida.liu.se/development/cvs/diff.xml?module=Pike&file=7.7/lib/mo… The rational for that is that I was once again reminded by a user this week that getting Process.create_process() or Process.Process right without some corner case blocking is hard. It's not obvious that if you bind pipes to booth stderr and stdout you have to take in to account that OS buffers are not limetless. Process.run() is a thin wrapper around Process.Process that collects stdout, stderr and exitcode and return them in a mapping. This could potentially result in huge strings, but will do what most users want and even already do when they call create_process() with both pipes bound. Something like this should be in 7.8, but I'm open to suggestions for other things that might be usefull to return in the mapping or for changing member names.

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Nettle
by Magnus Holmgren, Millnet AB (nu med fast anst�llning) ＠ Pike (-) developers forum 17 Jun '08

17 Jun '08

Could you upgrade the bundled version of Nettle to 1.15, which among other things, gets rid of a non-free RFC?

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pike version numbering
by Martin Bähr 31 May '08

31 May '08

hi, since i have seen a few references to pike version 7.10 i'd like to discuss the current versioning scheme. i'd like to suggest that the next version is numbered as pike 8. the main reason for that is that if we continue with 7.10, 7.12, etc, we will NEVER reach a state where the changes are large enough to get to pike 8 because after 7.10 and further switching to 8 will create expectations where pike 8 would be significantly different from pike 7. in other words: 7.8, 7.10 then will be our major versions, and the 7 in front would become rather meaningless. a succession like 7.6, 7.8, 8.0 seems natural and won't surprise anyone. ie: no one will expect a huge set of changes there. on the other hand the changes from 7.6 to 7.8 seem quite significant (syntax additions like getters and setters, etc) already, that i even think it may be waranted to go directly from 7.6 to 8. in any case however, we should never go to 7.10. greetings, martin.

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Blocks inside expressions
by Martin Nilsson (Opera Mini - AFK!) ＠ Pike (-) developers forum 31 May '08

31 May '08

That points towards the lack of need for inlined expression blocks, but it may just be that people have been conscious about the lambda overhead or thought a function would be more apropriate.

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Blocks inside expressions
by Martin Stjernholm, Roxen IS ＠ Pike developers forum 31 May '08

31 May '08

Aha, cute. Yes, that use would be exclusive with this one, unfortunately.

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Blocks inside expressions
by Martin Stjernholm, Roxen IS ＠ Pike developers forum 31 May '08

31 May '08

I don't know. What would these generators be?

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Blocks inside expressions
by Mirar ＠ Pike developers forum 31 May '08

31 May '08

Sounds good to me. Is that keyword used?

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Blocks inside expressions
by Martin Stjernholm, Roxen IS ＠ Pike developers forum 31 May '08

31 May '08

Not only, as said. It seems like a waste of time to fix inlining of that particular kind of lambdas (and I think it wouldn't be nearly as simple as this) when the end result is only less versatile and clumsier to write. Other kinds of lambdas, like e.g. those commonly used with map() and filter() would still not be possible to inline, btw. For that to work we'd have to change map(), filter(), etc to special builtin constructs.

1 0

Blocks inside expressions
by Martin Stjernholm, Roxen IS ＠ Pike developers forum 31 May '08

31 May '08

I've already mentioned some things that differs from lambdas. Another big difference is speed: No call overhead, local variables outside the block are faster to access, and it allows the optimizers to work across the block boundary.

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Blocks inside expressions
by Martin Stjernholm, Roxen IS ＠ Pike developers forum 31 May '08

31 May '08

An annoying thing with C and languages with C-like syntax is the distinction between statements and expressions. Specifically, that you lose some expressiveness in expression contexts since declarations and statements like for/while/switch etc can't be used in there. Gcc has an extension to allow blocks inside statements: One just puts a block inside parenthesis and writes statements there. E.g: ({ int y = foo (); int z; if (y > 0) z = y; else z = - y; z; }) The result of the expression is the last statement. It occurred to me that it would be really simple to add this to pike too. We already have gauge and catch which can open up statement blocks inside expressions, so we only need a variety that returns the value of the last statement expression. The gcc syntax doesn't work since ({ }) means arrays, so among the existing keywords I picked "inline": werror ("%d\n", inline { int s = 1; for (int i = 2; i < 7; i++) s *= i; s; }); Type checking of the last statement etc works just fine since the statement/expression distinction doesn't exist on the abstract syntax tree level anyway. If the last statement isn't an expression then the inline block will be of void type, so this gives "assigning a void expression": mixed c = inline { for (int i = 0; i < 10; i++) werror (" %O\n", i); }; This construct is different from lambdas (implicit or not) since the block is not a function of its own, but rather just another nested block. I.e. it's possible to exit it using "break" and "continue", and "return" will return from the surrounding function. I only made this for fun and haven't committed it yet. Here's the patch if someone wants to play around with it: --- src/language.yacc 30 May 2008 11:20:41 -0000 1.426 +++ src/language.yacc 31 May 2008 13:59:55 -0000 @@ -3674,6 +3674,10 @@ free_node ($3); } | expr4 TOK_ARROW line_number_info error {$$=$1; free_node ($3);} + | TOK_INLINE '{' statements comma_expr2 expected_semicolon end_block + { $$ = mknode (F_COMMA_EXPR, $3, $4); } + | TOK_INLINE '{' statements end_block + { $$ = $3; } ; idents2: idents The syntax is still open for discussion, of course. It would work to use e.g. "block {...}" instead; the new "block" keyword would not conflict with identifiers.

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Pike-devel May 2008