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Author Topic: common sub-expressions  (Read 3527 times)

damieiro

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Re: common sub-expressions
« Reply #15 on: August 27, 2021, 04:03:03 pm »
 :D :D
It could be funny having a poll of free pascal forum ages...

When did you born?
50-60s
60-70s
70s-80->i' m here more near than 70s :D

And so on..


Paolo

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Re: common sub-expressions
« Reply #16 on: August 27, 2021, 04:17:02 pm »
ehm.. let me say just before '70s :-[

Paolo

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Re: common sub-expressions
« Reply #17 on: August 27, 2021, 04:31:25 pm »
@markov,

Are there examples of symbolic unit usage ?

J-G

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Re: common sub-expressions
« Reply #18 on: August 27, 2021, 05:42:22 pm »
:D :D
It could be funny having a poll of free pascal forum ages...

When did you born?
50-60s
60-70s
70s-80->i' m here more near than 70s :D

And so on..
You started too late   ----  40's !!   8-)
FPC 3.0.0  Lazarus 1.6  Win 7 Ult 64

BobDog

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Re: common sub-expressions
« Reply #19 on: August 28, 2021, 11:04:23 am »

You are going the wrong way chronologically, you must go back deeper into the mists of time to catch me!


PascalDragon

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Re: common sub-expressions
« Reply #20 on: August 28, 2021, 11:42:03 am »
Everyone, please, back to topic. This is not about ones age, but about sub expressions.

MarkMLl

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Re: common sub-expressions
« Reply #21 on: August 28, 2021, 12:09:24 pm »
Seconded, FWIW. However I'd suggest that peoples' background /can/ be important in this area: as an engineer (and one who predates most CS departments) I'm inclined to be dismissive of stuff that sounds like CS geekery: but in this case the concept of an Abstract Syntax Tree that can be manipulated systematically is deeply important.

One thing I would say though is that it might turn out to be necessary to store the original source text at each node for debugging/listing purposes, but this can obviously be difficult to manipulate. So one might perforce end up with both storage for a source fragment, plus a way of regenerating something that approximates source from a node where e.g. two leaves have been exchanged to bring it in line with others which might at a later stage be elided as common subexpressions.

MarkMLl
Turbo Pascal v1 on CCP/M-86, multitasking with LAN and graphics in 128Kb.
Pet hate: people who boast about the size and sophistication of their computer.
GitHub repositories: https://github.com/MarkMLl?tab=repositories

marcov

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Re: common sub-expressions
« Reply #22 on: August 28, 2021, 12:15:21 pm »
@markov,

Are there examples of symbolic unit usage ?

there are some in packages\symbolic\examples, but they are quite basic. 

 

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