oh wow i just thought of a pretty wild syntax for

Question

oh wow i just thought of a pretty wild syntax for <https github com pantsbuild pants issues 7490> ```output = await Get Output input1 Input1 input2 Input2 ```

witty-crayon-22786 · Answer

works afaict because `Get` inputs must always be hash eq able

witty-crayon-22786 · Answer

and declares the type of the input as a dict value which ends up looking like a type ascription

witty-crayon-22786 · Answer

and leaves room for more syntax by expanding the dict value to indicate that something is optional etc

hundreds-father-404 · Answer

I like it Do you think something like this for 0 and 1 arg ```await Get Output input1 Input await Get Output ``` I think it s strongly worth considering converging around a single syntax for `Get` The rule API is already hard to learn having several different ways of using a core abstraction adds to the confusion

witty-crayon-22786 · Answer

maybe eventually

witty-crayon-22786 · Answer

the downside of this syntax is the performance implication of creating a dict my expectation is that callsites which use multiple parameters will be fairly rare though

hundreds-father-404 · Answer

so then zero param would be `await Get Output ` which I like Would 1 param stay the same as before with the 2 vs 3 arg variants

witty-crayon-22786 · Answer

yea i think that nothing changes for now for the 1 arg case and 0 arg looks like `Get Output `

witty-crayon-22786 · Answer

and who knows if multi argument callsites end up being way more common then the dict may not work we ll see

fast-nail-55400 · Answer

If we like this syntax will we be ad `dict` ed to it

bitter-ability-32190 · Answer

Should `input1` be a string

witty-crayon-22786 · Answer

No it is the actual value of that type

bitter-ability-32190 · Answer

dizzy face Got a real world example I m not grokking

bitter-ability-32190 · Answer

ohhhhhh it s ` instance type `

witty-crayon-22786 · Answer

yea

bitter-ability-32190 · Answer

They have to be static though for parsing s sake

witty-crayon-22786 · Answer

Only the types do

witty-crayon-22786 · Answer

But yes the shape and types of the dict are static

bitter-ability-32190 · Answer

grimacing I like the idea I m a bit weary of the parsing and of the 1 arg shorthand having to duplicate e g going from `Get X Y ` to `Get X Y Y `

witty-crayon-22786 · Answer

i don t think that we can should get rid of the 1 arg syntaxes yet

witty-crayon-22786 · Answer

but we ll see

hundreds-father-404 · Answer

yeah I take back my proposal to get rid of the 1 arg syntaxes for now

bitter-ability-32190 · Answer

parsing still seems like a stumbling block It s gonna be hard not to want to use variables sweat smile

witty-crayon-22786 · Answer

< bitter ability 32190> not sure what you mean there this is equivalent to the existing syntax in that regard

bitter-ability-32190 · Answer

Maybe to us As a newcomer it s even less obvious that we can t dynamically build inputs this way

bitter-ability-32190 · Answer

At least before there wasn t a mutable built in object s worth of wiggle room for getting creative slightly smiling face

hundreds-father-404 · Answer

you can the only thing that has to be explicitly set is the ` Input1` type which is the type ID the key can be a variable

witty-crayon-22786 · Answer

from a parsing perspective that sounds like quickly fail with a useful explanation if you encounter anything other than a dict literal

bitter-ability-32190 · Answer

a dict literal whose key value pairs are static e g no ` ` and whose values are types All that said I love the creativity and the idea I ll wait for the PR to see how creative we have to get slightly smiling face

witty-crayon-22786 · Answer

yea true

bitter-ability-32190 · Answer

I also wonder how we can make the multiple inputs really noticeable at the declaration site of a rule

witty-crayon-22786 · Answer

most of the time they won t be a `Platform` `Environment` will likely be consumed by most all processes that a ` rule` invokes transitively and in the computation of environment variables and options that it consumes again transitively but not in its signature

witty-crayon-22786 · Answer

for example

bitter-ability-32190 · Answer

You lost me stuck out tongue

witty-crayon-22786 · Answer

the reason that a `Get` is type driven is that it does not represent positional arguments to a particular rule rather the transitive inputs necessary to compute an output type

witty-crayon-22786 · Answer

witty-crayon-22786 · Answer

gt `Param`s are eventually used as positional args to `Rule`s but it s important to note that the `Param`s in a `Rule` instance s identity memoization key will not always become the positional arguments to that `Rule` in many cases a `Param` will be used by a `Rule` s transitive dependencies in order to produce an output value that becomes either a positional argument to the `Rule` as it starts or the result of a `Get` while a coroutine `Rule` runs

witty-crayon-22786 · Answer

the eventual need to differentiate entire subgraphs by the Platform is part of why the ` rule` API is shaped the way it s shaped