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> No, it means that one has types. {length: 3} has a very specific type. Shoving that into a struct Foo { double length; } doesn't make it any safer. A simple

> No, it means that one has types. {length: 3} has a very specific type. Shoving that into a struct Foo { double length; } doesn't make it any safer. A simple validator and properly naming fields to mention units makes you safer than types. > For that matter, is '{"length": "abc"}' incorrect? That's a non-issue with even the simplest of validators. > Having caught many, many bugs from strong types, I feel comfortable saying that you're incorrect here. Yet you still need a test suite to handle the huge holes left by the type-system. These tests will catch all bugs the strong types would along the way. Unless you're having a Hindley-Milner type system, chances are you're working in C++, Java or C# and bugs caught by these type-systems are very superficial. > If you don't have a solid sanitisation/marshalling/untainting/whatever-you-call-it layer, you're going to have security and other correctness errors. Totally agree, but you don't need types or XML for that. Having worked as much with statically typed languages and dynamic ones, I'll chose the later any day unless I have very strict performance/memory requirements which is not happening for 99.9% of projects. Types might catch the easy and superficial bugs, but my ability to reason prevents the hard ones. Having orders of magnitude less code to think about is exactly what I want to achieve it.

zeveb 10y ago
> > For that matter, is '{"length": "abc"}' incorrect? > That's a non-issue with even the simplest of validators. That's the point: the user-marshalled data must pass through the validator, and once it's passed through, it's no longer the same type. Perl figured this out with its taint mode 20 years ago. We shouldn't be still exposing ourselves to these sorts of bugs. > Unless you're having a Hindley-Milner type system, chances are you're working in C++, Java or C# and bugs caught by these type-systems are very superficial. If a better tool is available, why use a lesser? > Totally agree, but you don't need types or XML for that. I'm not arguing for XML. XML is almost as horrendous an embarrassment for the profession of software development as is JavaScript. If someone is looking for a data-interchange format and settles on XML, something is deeply wrong with either him or his situation. XML's just terrible. But passing around JSON objects within one's code is insane. JSON is a (decent) data-transfer format, an completely unsuitable for computation. > Types might catch the easy and superficial bugs, but my ability to reason prevents the hard ones. Having orders of magnitude less code to think about is exactly what I want to achieve it. I completely agree, which is why I don't use XML, JSON, JavaScript, C or Java. It's why I use a marshalling layer: I only have to think about user-marshalled data in that layer; I get to only think about my problem set everywhere else.
- jeremiep 10y ago
  > and once it's passed through, it's no longer the same type. How is that different from loading a JSON into custom data structures? You run the exact same validation step, have the exact same data for input, but your result is now unusable by the entirety of your generic data functions. You'd be better off with a hash-map than a class. > If a better tool is available, why use a lesser? Because no tool is better all across the board. Otherwise we'd have the holy grail of programming languages right there. However, I'll favor productivity and the ability to reason about code over performance or some weak validation that I didn't make a typo or sent a string where a boolean was expected. Besides, I have already spent weeks trying to debug type errors in C++; its ridiculously easy to break the type system. I've also had countless cast exceptions in both Java and C#; how are types helping there? If anything they give you the illusion of correctness. > But passing around JSON objects within one's code is insane. That's not at all what you do. When you do JSON.parse the result is already using the language's data structures; there is no concept of "JSON objects". Even in C#/Java you can map these to dictionaries or use reflection to directly map these to ad-hoc structures/classes. > I completely agree, which is why I don't use XML, JSON, JavaScript, C or Java. Its rarely up to you. There aren't many endpoints supporting something other than JSON or XML. Anything running in the browser is automatically running JavaScript; anything embedded will go for C. Once the data is past the validator, its no longer user-marshalled data. Its just data. Wrapping it around ad-hoc types doesn't help your problem domain, it just adds yet another level of indirection you could easily do without. [edit] I should also add that I strongly favor YAML over JSON for two simple reasons; the format is both versioned and extensible. That fixes the problem in JSON of using string conventions for fancier types like dates. There I can load the data directly in exactly the shape I want it to.
  - zeveb 10y ago
    > How is that different from loading a JSON into custom data structures? That's what I'm arguing for doing. I thought that you were arguing for using JSON data structures rather than custom data structures. > You run the exact same validation step, have the exact same data for input, but your result is now unusable by the entirety of your generic data functions. What do you mean by 'generic data functions'? I can do whatever I like with whatever parts of my language I wish. > Besides, I have already spent weeks trying to debug type errors in C++; its ridiculously easy to break the type system. I've also had countless cast exceptions in both Java and C#; how are types helping there? If anything they give you the illusion of correctness. They're not: C++, Java & C# are all examples of lesser tools. That's why I don't use them. > When you do JSON.parse the result is already using the language's data structures Which is what's insane. I don't want a dictionary; I want an instance. > Once the data is past the validator, its no longer user-marshalled data. Its just data. And we discovered decades ago that it's useful to talk about categories of data (types) and about data that carries along with it behaviour (classes). Why limit yourself to whacking things with a stick to collect pinecones when you can use a starship to explore the galaxy? > Wrapping it around ad-hoc types doesn't help your problem domain, it just adds yet another level of indirection you could easily do without. Programming is all about building intelligent abstractions which enable you to reason at a higher level. I don't want to think about the third item of an array which is the value of a property name 'foo'; I want to think about interest rates, organisational rules and categories. I like YAML too; it's a decent format. Not perfect, but decent. Bit big though. I'd prefer something lighter weight like S-expressions though: just enough structure to make it easy to turn into native objects.

zeveb 10y ago

> > For that matter, is '{"length": "abc"}' incorrect? > That's a non-issue with even the simplest of validators. That's the point: the user-marshalled data must pass through the validator, and once it's passed through, it's no longer the same type. Perl figured this out with its taint mode 20 years ago. We shouldn't be still exposing ourselves to these sorts of bugs. > Unless you're having a Hindley-Milner type system, chances are you're working in C++, Java or C# and bugs caught by these type-systems are very superficial. If a better tool is available, why use a lesser? > Totally agree, but you don't need types or XML for that. I'm not arguing for XML. XML is almost as horrendous an embarrassment for the profession of software development as is JavaScript. If someone is looking for a data-interchange format and settles on XML, something is deeply wrong with either him or his situation. XML's just terrible. But passing around JSON objects within one's code is insane. JSON is a (decent) data-transfer format, an completely unsuitable for computation. > Types might catch the easy and superficial bugs, but my ability to reason prevents the hard ones. Having orders of magnitude less code to think about is exactly what I want to achieve it. I completely agree, which is why I don't use XML, JSON, JavaScript, C or Java. It's why I use a marshalling layer: I only have to think about user-marshalled data in that layer; I get to only think about my problem set everywhere else.

jeremiep 10y ago
> and once it's passed through, it's no longer the same type. How is that different from loading a JSON into custom data structures? You run the exact same validation step, have the exact same data for input, but your result is now unusable by the entirety of your generic data functions. You'd be better off with a hash-map than a class. > If a better tool is available, why use a lesser? Because no tool is better all across the board. Otherwise we'd have the holy grail of programming languages right there. However, I'll favor productivity and the ability to reason about code over performance or some weak validation that I didn't make a typo or sent a string where a boolean was expected. Besides, I have already spent weeks trying to debug type errors in C++; its ridiculously easy to break the type system. I've also had countless cast exceptions in both Java and C#; how are types helping there? If anything they give you the illusion of correctness. > But passing around JSON objects within one's code is insane. That's not at all what you do. When you do JSON.parse the result is already using the language's data structures; there is no concept of "JSON objects". Even in C#/Java you can map these to dictionaries or use reflection to directly map these to ad-hoc structures/classes. > I completely agree, which is why I don't use XML, JSON, JavaScript, C or Java. Its rarely up to you. There aren't many endpoints supporting something other than JSON or XML. Anything running in the browser is automatically running JavaScript; anything embedded will go for C. Once the data is past the validator, its no longer user-marshalled data. Its just data. Wrapping it around ad-hoc types doesn't help your problem domain, it just adds yet another level of indirection you could easily do without. [edit] I should also add that I strongly favor YAML over JSON for two simple reasons; the format is both versioned and extensible. That fixes the problem in JSON of using string conventions for fancier types like dates. There I can load the data directly in exactly the shape I want it to.
- zeveb 10y ago
  > How is that different from loading a JSON into custom data structures? That's what I'm arguing for doing. I thought that you were arguing for using JSON data structures rather than custom data structures. > You run the exact same validation step, have the exact same data for input, but your result is now unusable by the entirety of your generic data functions. What do you mean by 'generic data functions'? I can do whatever I like with whatever parts of my language I wish. > Besides, I have already spent weeks trying to debug type errors in C++; its ridiculously easy to break the type system. I've also had countless cast exceptions in both Java and C#; how are types helping there? If anything they give you the illusion of correctness. They're not: C++, Java & C# are all examples of lesser tools. That's why I don't use them. > When you do JSON.parse the result is already using the language's data structures Which is what's insane. I don't want a dictionary; I want an instance. > Once the data is past the validator, its no longer user-marshalled data. Its just data. And we discovered decades ago that it's useful to talk about categories of data (types) and about data that carries along with it behaviour (classes). Why limit yourself to whacking things with a stick to collect pinecones when you can use a starship to explore the galaxy? > Wrapping it around ad-hoc types doesn't help your problem domain, it just adds yet another level of indirection you could easily do without. Programming is all about building intelligent abstractions which enable you to reason at a higher level. I don't want to think about the third item of an array which is the value of a property name 'foo'; I want to think about interest rates, organisational rules and categories. I like YAML too; it's a decent format. Not perfect, but decent. Bit big though. I'd prefer something lighter weight like S-expressions though: just enough structure to make it easy to turn into native objects.