Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>What level of abstraction are you working where you "need to add subtyping"?</p> <ol> <li>Are you trying to create world model for your program encoded by Haskell types? (I can see this if your types are <em>actually</em> <code>Animal</code>, <code>Dog</code>, etc.)</li> <li>Are you trying to create more general software, and you think subtypes would be a good design?</li> <li>Or are you just learning haskell and playing around with things.</li> </ol> <p>If (1), I think that will not work out for you so well. Haskell does not have very good reflective abilities -- i.e. ability to weave type logic into runtime logic. Your model would end up pretty deeply entangled with the implementation. I would suggest creaing a "world model" (set of) types, as opposed to a set of types corresponding to a specific world model. I.e., answer this question for Haskell: what is a world model?</p> <p>If (2), think again :-). Subtyping is part of a design tradition in which Haskell does not participate. There are other ways to design your program, and they will end up playing nicer with the functional mindset then subtyping would have. It takes times to develop your functional design sense, so be patient with it. Just remember: keep it simple, stupid. Use data types and functions over them (but remember to use higher-order functions to generalize and share code). If you are reaching for advanced features (even typeclasses are fairly advanced in the sense I mean), you are probably doing it wrong.</p> <p>If (3), see Doug's answer, and play with stuff. There are lots of ways to fake it, and they all kind of suck eventually.</p>
    singulars
    1. This table or related slice is empty.
    1. POSubtypes for natural language types
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USluqui
    1. USluqui
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COBasically I'm starting with (3). It is not over a week since I started working on Haskell (did some Prolog/Python in the Uni but that was not very relevant and also many years ago). Thanks a lot for your answer
      singulars
      1. PO
      1. USuser1198580
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload