ANN: Dogelog Runtime, Prolog to the Moon (2021)

[alister]

On Wed, 15 Sep 2021 11:31:48 -0700, Mostowski Collapse wrote:

> There is a further problem with this:
> 
>> for i,term in enumerate(term.args):
>> ____mark_term(term.args[i])
> 
> It should read:
> 
> for i,help in enumerate(term.args):
> ____mark_term(help)
> 
> But then i isn't need.
even Better (i had only skimmed the code as I was certain I would find 
this, it is probably the No. 1 thing new python programmers get wrong
if your example is correct the it can be simplified even further to

for help in term.args:
    mark_term(help)

& if help does not get used after this loop then a comprehension is even 
better
_ == [mark_term(help) for help in term.args]


the underscore character is python convention for an unneeded place-
holder variable.

> 
> Mostowski Collapse schrieb am Mittwoch, 15. September 2021 um 20:22:50
> UTC+2:
>> Do you mean, replace this:
>> i = 0 while i < len(term.args) - 1:
>> ____mark_term(term.args[i])
>> ____i += 1 term = term.args[i]
>> 
>> By this:
>> 
>> for i,term in enumerate(term.args):
>> ____mark_term(term.args[i])
>> 
>> This wouldn't be correct anymore. The recursive call is only for the
>> arguments except for the last one one.
>> alister schrieb am Mittwoch, 15. September 2021 um 20:17:23 UTC+2:
>> > On Wed, 15 Sep 2021 18:23:10 +0200, Mostowski Collapse wrote:
>> > 
>> > > I really wonder why my Python implementation is a factor 40 slower
>> > > than my JavaScript implementation.
>> > > Structurally its the same code.
>> > > 
>> > > You can check yourself:
>> > > 
>> > > Python Version:
>> > > https://github.com/jburse/dogelog-moon/blob/main/devel/runtimepy/
>> > machine.py
>> > > 
>> > > JavaScript Version:
>> > > https://github.com/jburse/dogelog-moon/blob/main/devel/runtime/
>> > machine.js
>> > > 
>> > > Its the same while, if-then-else, etc.. its the same classes
>> > > Variable, Compound etc.. Maybe I could speed it up by some details.
>> > > For example to create an array of length n, I use in Python:
>> > > 
>> > > temp = [NotImplemented] * code[pos]
>> > > pos += 1
>> > > 
>> > > Whereas in JavaScript I use, also in exec_build2():
>> > > 
>> > > temp = new Array(code[pos++]);
>> > > 
>> > > So I hear Guido doesn't like ++. So in Python I use +=
>> > > and a separate statement as a workaround. But otherwise,
>> > > what about the creation of an array,
>> > > 
>> > > is the the idiom [_] * _ slow? I am assuming its compiled away. Or
>> > > does it really first create an array of size 1 and then enlarge it?
>> > > 
>> > > Julio Di Egidio wrote:
>> > <sniped due to top posting>
>> > 
>> > this is probably a string contender
>> > 
>> > i = 0 while i < len(term.args) - 1:
>> > mark_term(term.args[i])
>> > i += 1 term = term.args[i]
>> > 
>> > try replacing with something more pythonic
>> > 
>> > for index,term in enumerate(term.args):
>> > mark_term(term.args[i])
>> > 
>> > 
>> > & possibly go all the way to changing it into a comprehension
>> > 
>> > there are other similar anti patterns throughout this code.
>> > 
>> > any time you are manually keeping a counter as an index into a
>> > list,tupple other iterable YOU ARE DOING IT WRONG!
>> > 
>> > Do not write javascript in python, write python
>> > 
>> > 
>> > 
>> > --
>> > Two percent of zero is almost nothing.
>> > 
>> > 
>> > 
>> > 
>> > --
>> > Whoever dies with the most toys wins.





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