#development
Title
h
hundreds-breakfast-49010
10/01/2019, 1:02 AMso could I write an
@ruleTuple[X]a
aloof-angle-91616
10/01/2019, 1:03 AMyes, but we recommend using
Collection.ofh
hundreds-father-404
10/01/2019, 1:03 AMNB:
Tuple[X]Tuple[X, ...]h
hundreds-breakfast-49010
10/01/2019, 1:03 AMwhat's the difference?
h
hundreds-father-404
10/01/2019, 1:03 AMTuple[X]Tuple[X, ...]h
hundreds-breakfast-49010
10/01/2019, 1:03 AMso I'd write the rule
@rule\ndef my_rule(x: Collection.of(WhateverType)) -> OutputType:...and then use it like
x = yield Get(OutputType, WhateverType, (a, b, c,))a
aloof-angle-91616
10/01/2019, 1:04 AMthe type has to be saved to a variable -- see
src/python/pants/engine/build_files.pyCollectionOfWhatever = Collection.of(WhateverType)h
hundreds-breakfast-49010
10/01/2019, 1:04 AMah okay
w
witty-crayon-22786
10/01/2019, 4:00 PMbut also, remember our discussion about `Collection.of`: it doesn't add any useful information to the type
so we probably ought to use less of it.
a
aloof-angle-91616
10/01/2019, 4:01 PMah ok
the thing about
Tuple[...]w
witty-crayon-22786
10/01/2019, 4:02 PMthat's on me... need to improve the docs there maybe.
well, my point applies to Tuple/Collection/List/anything
a
aloof-angle-91616
10/01/2019, 4:02 PMbecause a collection of X is a
Tuple[X, X, X, X, X, ...]yes
w
witty-crayon-22786
10/01/2019, 4:03 PMk
a
aloof-angle-91616
10/01/2019, 4:03 PMwe just need some way to represent collections
definitely agree with your point in general
w
witty-crayon-22786
10/01/2019, 4:05 PMthe gist of the comment on the ticket is "make a newtype", maybe extending from
Collection.ofi see the general point about Tuple though... that's unfortunate. is there a
Tuple[*X]a
aloof-angle-91616
10/01/2019, 4:06 PMgreat question
h
hundreds-breakfast-49010
10/01/2019, 5:17 PMit's pretty easy to make a newtype that wraps a tuple of the things you wanted to include in a novel rule
but that adds a little bit of friction
a
aloof-angle-91616
10/01/2019, 6:33 PMdoes it? i always felt like that was a really good thing, to name everything with its own struct when possible
not trying to say i'm right, that is just my personal emotional response
feels nice to have names for things
w
witty-crayon-22786
10/01/2019, 6:34 PM@hundreds-breakfast-49010: what is the actual usecase involved here?
h
hundreds-breakfast-49010
10/01/2019, 6:36 PMI wanted to write this rule in this PR: https://github.com/pantsbuild/pants/pull/8369/commits/8af08d8ef28ec8526757bc1c06e7f14d317a7f21#diff-7acfea499dbc0e147308fc0681d40184R29 as taking as its input a native python tuple of
PythonTargetAdaptorI ended up creating a newtype for it
w
witty-crayon-22786
10/01/2019, 6:40 PM@hundreds-breakfast-49010: should that just be a private function?
or are you actually trying to allow for it to be reused more generally?
h
hundreds-breakfast-49010
10/01/2019, 6:43 PMyeah it's an
@ruleso it's meant to be generally available
w
witty-crayon-22786
10/01/2019, 6:47 PMhm. k
yea, there is some amount of cost in extracting a
@ruleand that will probably drive how granular they are.
...which is a good thing, i think.
a
aloof-angle-91616
10/01/2019, 9:43 PMagreed^