[OT] Re^4: perl compiler optimizer curiosity

if I say "macro" I mean real ones like in Lisp. Preprocessor macros like in C are sh*t in comparison.

I never used Lisp, but I know C. Can you show some examples?

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

Comment on [OT] Re^4: perl compiler optimizer curiosity

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Re^5: perl compiler optimizer curiosity (syntactic macros) by LanX (Saint) on Mar 15, 2022 at 12:16 UTC
We had this discussion multiple times before, but I can't find those threads in a hurry. Preprocessing/source filter means you have an second parsing stage which has not only to reproduce the whole syntax (horror in Perl) but might also expand to unpredictable results when combined (like two source filters) Lisp'ish Syntactic macros: look and parse like functions the arguments are used as building blocks for an "expanded" template the expansion happen while compiling in the same stage don't require any syntax parsing by themselves can be used to efficiently extend syntax There are still some traps, like the need for "hygiene", but this a problem with dumber source filters too. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery} update see also https://en.wikipedia.org/wiki/Macro_(computer_science)#Syntactic_macros	[reply]

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Re^5: perl compiler optimizer curiosity (syntactic macros)
by LanX (Saint) on Mar 15, 2022 at 12:16 UTC

Preprocessing/source filter means you have an second parsing stage which has not only to reproduce the whole syntax (horror in Perl) but might also expand to unpredictable results when combined (like two source filters)

Lisp'ish Syntactic macros:

look and parse like functions
the arguments are used as building blocks for an "expanded" template
the expansion happen while compiling in the same stage
don't require any syntax parsing by themselves
can be used to efficiently extend syntax

There are still some traps, like the need for "hygiene", but this a problem with dumber source filters too.

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

update

https://en.wikipedia.org/wiki/Macro_(computer_science)#Syntactic_macros

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