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How widely understood and appreciated were algebraic data types at the time Cfront was first floated as the precursor to C++? To what degree had they shown up i

How widely understood and appreciated were algebraic data types at the time Cfront was first floated as the precursor to C++? To what degree had they shown up in mainstream languages?

tialaramex 2y ago
Well if you want to compare to why C++ has multiple inheritance, you need to first explain which mainstream languages in the mid-1980s had multiple inheritance so we can contrast. Like algebraic data types, multiple inheritance wasn't novel, but what were the big famous languages from that time which showed this was a must have for Bjarne's language?
- JoshTriplett 2y ago
  That's not the comparison I'm making. It's possible for a proposed language to add something despite not being popular at the time, but that's not the default. I'm suggesting that if ADTs were not already popular at the time, it would be the unsurprising default for them to not be in a new language. In today's language landscape, by contrast, it would be surprising and disappointing for a new language to not have either ADTs or a specific alternative they propose for solving the same problem.
  - tialaramex 2y ago
    But the actual answer is revealing. Bjarne implemented multiple inheritance in C++ because it was easy. It's a New Jersey language. The priority is simplicity of implementation. It's not about what was popular, or that Stroustrup was at Cambridge not Edinburgh (all the exciting Programming Language theory stuff in that era like ML was from Edinburgh as you perhaps know). If ADTs were easy, C++ would have ADTs.
tubthumper8 2y ago
Cfront being around 1983 would mean at least ALGOL68 and Pascal would've been well-known at the time. Ada is cited as an influence on C++. ML languages were definitely not mainstream but if Wikipedia is to be believed, ML was an influence on C++ as well. The idea would've been well understood, but if the goal of C++ was "C with classes" or more accurately "C + Simula" then it just wasn't part of the goal. And of course we got 20 years of essentially forgetting that sum types existed outside of ML languages until they were "rediscovered"

How widely understood and appreciated were algebraic data types at the time Cfront was first floated as the precursor to C++? To what degree had they shown up in mainstream languages?

tialaramex 2y ago

Well if you want to compare to why C++ has multiple inheritance, you need to first explain which mainstream languages in the mid-1980s had multiple inheritance so we can contrast. Like algebraic data types, multiple inheritance wasn't novel, but what were the big famous languages from that time which showed this was a must have for Bjarne's language?

JoshTriplett 2y ago
That's not the comparison I'm making. It's possible for a proposed language to add something despite not being popular at the time, but that's not the default. I'm suggesting that if ADTs were not already popular at the time, it would be the unsurprising default for them to not be in a new language. In today's language landscape, by contrast, it would be surprising and disappointing for a new language to not have either ADTs or a specific alternative they propose for solving the same problem.
- tialaramex 2y ago
  But the actual answer is revealing. Bjarne implemented multiple inheritance in C++ because it was easy. It's a New Jersey language. The priority is simplicity of implementation. It's not about what was popular, or that Stroustrup was at Cambridge not Edinburgh (all the exciting Programming Language theory stuff in that era like ML was from Edinburgh as you perhaps know). If ADTs were easy, C++ would have ADTs.

tubthumper8 2y ago

Cfront being around 1983 would mean at least ALGOL68 and Pascal would've been well-known at the time. Ada is cited as an influence on C++. ML languages were definitely not mainstream but if Wikipedia is to be believed, ML was an influence on C++ as well. The idea would've been well understood, but if the goal of C++ was "C with classes" or more accurately "C + Simula" then it just wasn't part of the goal. And of course we got 20 years of essentially forgetting that sum types existed outside of ML languages until they were "rediscovered"