3
$\begingroup$

Is there a way to modify the parser, or define options, to align the indentation of a sequence of Queries on a Dataset?

Given:

ds = <|"a" -> 1, "b" -> <|"c" -> 2|>, "d" -> <|"e" -> 3, "f" -> <|"g" -> 4|>|>|> // Dataset;

A sequence of queries is indented like this:

ds[
    {"b" -> {"c" -> foo}}][
   {"d" -> {"e" -> bar}}][
  {"d" -> {"f" -> {"g" -> baz}}}][
 {"d" -> {{"f" -> quz}}}]

There are 2 problems with this format in practice with realistic workflows where queries are often lengthy and need to be modified repeatedly:

  1. The lines are staggered - it would be desirable to have them left-aligned, as applications with many lines continues to accumulate that slope, making spot-checking of depth more difficult than it should be.

  2. The open bracket "[" of each query appears on the line above it, making it more difficult than necessary to highlight a query (eg, to delete it). It would be more modular to confine each on its own line, but doing so results in a syntax error:

 Syntax::sntxb: Expression cannot begin with "[{d->{e->bar}}][{d->{f->{g->baz}}}]".

Interestingly, writing out Query solves the 2nd problem but not the first:

ds // 
 Query[{"b" -> {"c" -> foo}}] /*
  Query[ {"d" -> {"e" -> bar}}] /* 
    Query[ {"d" -> {"f" -> {"g" -> baz}}}] /*
      Query[ {"d" -> {{"f" -> quz}}}]

Note, chaining queries using RightComposition reverses the indentation compared to \, which also works.

$\endgroup$
5
  • 1
    $\begingroup$ You can use Code cell style. $\endgroup$
    – Kuba
    Nov 23, 2016 at 18:49
  • $\begingroup$ @Kuba, great, can you give an example? Any downstream effects? $\endgroup$ Nov 23, 2016 at 18:50
  • $\begingroup$ They are gray :) and also have InitializationCell->True option but this can be switched on notebook or stylesheet level if you need it. As to examples, select bracket and Alt+8 $\endgroup$
    – Kuba
    Nov 23, 2016 at 18:53
  • $\begingroup$ @Kuba, converting to Code style seems to work for issue 1 but not for 2, where it still throws a syntax error. $\endgroup$ Nov 23, 2016 at 19:16
  • $\begingroup$ Right, the same as with /., don't have a quick solution for you, sorry. $\endgroup$
    – Kuba
    Nov 23, 2016 at 19:18

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.