3 ms·

There are even more algebras on the same bits, when you take signed integers into account, such as saturating arithmetic. One interesting programming language

by xgk 6mo ago

There are even more algebras on the same bits, when you take signed integers into account, such as saturating arithmetic. One interesting programming language construct that might be useful in this context are Opaque Type Synonyms, a refined form of C's typedef, which modern languages like Rust, Haskell, Go or Scala offer. This allows the programmer to use the same underlying types (e.g. int), give it different names, and define different algebras with the alias. The typing system prevents the different aliases accidentally to flow into each other. Of course that alone does not help to manage the profusion of algebras over the same bits. I think a better approach for a high-level programming language is to follow assembly and really use different names for different operations, e.g. not have + build in. Instead use explicit names like add_uint32, add_polynomials_gf_2, add_satur_arith, etc etc. The user can then explicitly define (scoped) aliases for them, including +, as long as the typing system can disambiguate the uses. The Sail DSL for ISA specification (https://github.com/rems-project/sail https://github.com/rems-project/sail) does this, and it is nice.

uecker 6mo ago
A user in C can just wrap the type in a structure and define explicit operations on it. You do not need another language for this.
- xgk 6mo ago
  Indeed, that is the standard approach. It is also how some of the aforementioned languages desugar opaque type synonyms during compilation. It has the slight disadvantage that we can no longer use variables like x in some situations, but need to use x._polynomials_gf_2 or whatever is the structure's field name. It is nice to avoid this boilerplate, which can become annoying quickly. Let the type-checker not the human do this work ... > You do not need another language for this. By the Church-Turing thesis you never need another language, but empirical practise has shown that the software engineering properties we see with real-world code and real-world programmers differ significantly between languages.
  - uecker 6mo ago
    You could call it x.val, no need to use a long field name. But you would rarely access it directly anyway. I do not see any type checking advantage here for other languages.

by xgk 6mo ago

uecker 6mo ago

A user in C can just wrap the type in a structure and define explicit operations on it. You do not need another language for this.

xgk 6mo ago
Indeed, that is the standard approach. It is also how some of the aforementioned languages desugar opaque type synonyms during compilation. It has the slight disadvantage that we can no longer use variables like x in some situations, but need to use x._polynomials_gf_2 or whatever is the structure's field name. It is nice to avoid this boilerplate, which can become annoying quickly. Let the type-checker not the human do this work ... > You do not need another language for this. By the Church-Turing thesis you never need another language, but empirical practise has shown that the software engineering properties we see with real-world code and real-world programmers differ significantly between languages.
- uecker 6mo ago
  You could call it x.val, no need to use a long field name. But you would rarely access it directly anyway. I do not see any type checking advantage here for other languages.