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Option #2 assumes that 0 is falsy. Its an OK assumption for a language like C but for languages that let lots of different things go into an if condition I pref

by ufo 11y ago

Option #2 assumes that 0 is falsy. Its an OK assumption for a language like C but for languages that let lots of different things go into an if condition I prefer for zero to be truthy and just false / null / etc to be falsy.

JoshTriplett 11y ago
Banning implicit integer conversions, such that neither 0 nor 1 can be used in a conditional, isn't unreasonable; then you have to write a boolean operator or conversion explicitly. However, if you allow integers in conditionals, yet have 0 mean true, you will break the default expectations of far too many programmers.
- jfarmer 11y ago
  The first several languages I learned treated 0 as falsey and I can't really recall it tripping me up when I learned a language (Ruby) where that's not the case. I suppose always thought of 0-as-false as an unfortunate consequence of C not having a native boolean type, anyhow.
- ufo 11y ago
  In a statically typed language, restricting if conditionals to just booleans is the approach I like the most: simple and safe. On the other hand, in dynamic languages, where you can pass anything to conditional I think that treating 0 as falsy is very error prone. For example, its very common to use conditionals to implement default values: function foo(name){ name = name || "default name"; } In this setting, having 0 and "" act as falsy is a bug waiting to happen. On the other hand, having 0 act as truthy might confuse you a bit the first time you come across it but its an easy fix (just write x != 0 instead) and its not very likely to hit you when you don't expect it.
  - JoshTriplett 11y ago
    If your language has something like "None" or "null", then you should be checking against that to implement a default, rather than checking a truth value. After all, what if you wanted to implement a boolean parameter with a default value? Personally, I'm a big fan of languages with a "Maybe" type for this kind of thing.
    - deleted 11y ago
      [deleted]
    - ufo 11y ago
      The `||` pattern is super common in a bunch of languages though and to code it with a `== null` test you would need to expand it to a full blown ternary operator name != null ? name : "default name" Some languages have a "null-coalescing" operator you can use in these cases but its a niche thing. (And I agree with you on the Maybe thing but, as I said previously, 0 in conditionals is not a problem when conditionals have to be boolean)
      - JoshTriplett 11y ago
        My point is, you should be checking for null or None or equivalent, rather than boolean false; once you do, 0 being false is no more or less of a problem than false being false.
      - Someone 11y ago
        "Some languages have a "null-coalescing" operator you can use in these cases but its a niche thing." I see that not as niche, but as a fairly recent invention, or at least one that recently is becoming popular. IMO, C#'s ?? is superior to reusing binary operators. Advantages are that it looks more like the ternary operator, and that it doesn't require adding implicit conversions to boolean to your language.

by ufo 11y ago

JoshTriplett 11y ago

Banning implicit integer conversions, such that neither 0 nor 1 can be used in a conditional, isn't unreasonable; then you have to write a boolean operator or conversion explicitly. However, if you allow integers in conditionals, yet have 0 mean true, you will break the default expectations of far too many programmers.

jfarmer 11y ago
The first several languages I learned treated 0 as falsey and I can't really recall it tripping me up when I learned a language (Ruby) where that's not the case. I suppose always thought of 0-as-false as an unfortunate consequence of C not having a native boolean type, anyhow.
ufo 11y ago
In a statically typed language, restricting if conditionals to just booleans is the approach I like the most: simple and safe. On the other hand, in dynamic languages, where you can pass anything to conditional I think that treating 0 as falsy is very error prone. For example, its very common to use conditionals to implement default values: function foo(name){ name = name || "default name"; } In this setting, having 0 and "" act as falsy is a bug waiting to happen. On the other hand, having 0 act as truthy might confuse you a bit the first time you come across it but its an easy fix (just write x != 0 instead) and its not very likely to hit you when you don't expect it.
- JoshTriplett 11y ago
  If your language has something like "None" or "null", then you should be checking against that to implement a default, rather than checking a truth value. After all, what if you wanted to implement a boolean parameter with a default value? Personally, I'm a big fan of languages with a "Maybe" type for this kind of thing.
  - deleted 11y ago
    [deleted]
  - ufo 11y ago
    The `||` pattern is super common in a bunch of languages though and to code it with a `== null` test you would need to expand it to a full blown ternary operator name != null ? name : "default name" Some languages have a "null-coalescing" operator you can use in these cases but its a niche thing. (And I agree with you on the Maybe thing but, as I said previously, 0 in conditionals is not a problem when conditionals have to be boolean)
    - JoshTriplett 11y ago
      My point is, you should be checking for null or None or equivalent, rather than boolean false; once you do, 0 being false is no more or less of a problem than false being false.
    - Someone 11y ago
      "Some languages have a "null-coalescing" operator you can use in these cases but its a niche thing." I see that not as niche, but as a fairly recent invention, or at least one that recently is becoming popular. IMO, C#'s ?? is superior to reusing binary operators. Advantages are that it looks more like the ternary operator, and that it doesn't require adding implicit conversions to boolean to your language.