Databases
StackOverflow2013
Postsdbo
POHow to Work with Ruby Duck Typing
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to Work with Ruby Duck Typing
    primarykey
    data
    text
    <p>I am learning Ruby and I'm having a major conceptual problem concerning typing. Allow me to detail why I don't understand with paradigm.</p> <p>Say I am method chaining for concise code as you do in Ruby. I have to precisely know what the return type of each method call in the chain, otherwise I can't know what methods are available on the next link. Do I have to check the method documentation every time?? I'm running into this constantly running tutorial exercises. It seems I'm stuck with a process of reference, infer, run, fail, fix, repeat to get code running rather then knowing precisely what I'm working with during coding. This flies in the face of Ruby's promise of intuitiveness.</p> <p>Say I am using a third party library, once again I need to know what types are allow to pass on the parameters otherwise I get a failure. I can look at the code but there may or may not be any comments or declaration of what type the method is expecting. I understand you code based on methods are available on an object, not the type. But then I have to be sure whatever I pass as a parameter has all the methods the library is expect, so I still have to do type checking. Do I have to hope and pray everything is documented properly on an interface so I know if I'm expected to give a string, a hash, a class, etc.</p> <p>If I look at the source of a method I can get a list of methods being called and infer the type expected, but I have to perform analysis.</p> <p><a href="https://stackoverflow.com/questions/177080/ruby-and-duck-typing-design-by-contract-impossible">Ruby and duck typing: design by contract impossible?</a></p> <p>The discussions in the preceding stackoverflow question don't really answer anything other than "there are processes you have to follow" and those processes don't seem to be standard, everyone has a different opinion on what process to follow, and the language has zero enforcement. Method Validation? Test-Driven Design? Documented API? Strict Method Naming Conventions? What's the standard and who dictates it? What do I follow? Would these guidelines solve this concern <a href="https://stackoverflow.com/questions/616037/ruby-coding-style-guidelines">https://stackoverflow.com/questions/616037/ruby-coding-style-guidelines</a>? Is there editors that help?</p> <p>Conceptually I don't get the advantage either. You need to know what methods are needed for any method called, so regardless you are typing when you code anything. You just aren't informing the language or anyone else explicitly, unless you decide to document it. Then you are stuck doing all type checking at runtime instead of during coding. I've done PHP and Python programming and I don't understand it there either. </p> <p>What am I missing or not understanding? Please help me understand this paradigm.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USCommunity
    1. USkamegami
    plurals
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThere are certainly advantages to duck typing, but there are of course disadvantages as well. I can pass *any* object to a method `foo(a)` that calls `a.bar` as long as `a.responds_to?(:bar)`. That's nice. No interfaces, no generics, just add a method `bar` and go. Of course, static typing has many advantages as well. Sounds like you just need some experience with the Ruby way to appreciate both. Also sounds like you may have been a bit spoiled by intellisense (or similar features). Many (*many*) of us have to check documentation early and often.
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. USEd S.
    2. COIntuition is the result of training so nothing is intuitive until you've trained yourself to use it.
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. USmu is too short
    3. COThis question suffers from "TL;DR". It'd help for you to summarize it and throw away the rest otherwise it's too broad. "This flies in the face of Ruby's promise of intuitiveness." Intuitiveness to who? Matz says it's designed to be intuitive to him, and that he believes it will become intuitive to others who have used it sufficiently. It's impossible to create a language that is immediately intuitive to everyone, so his goal is spot-on.
      singulars
      1. POHow to Work with Ruby Duck Typing
      1. USthe Tin Man
 

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