Comment by AlienRobot
10 hours ago
The worst thing is being corrected about minutiae. It's not a "property" it's an attribute/field/member/key/column/variable/getter/function/procedure. Deep down it's all variables. Even the constants are variables from the viewpoint of the CPU that has to load it in its registers.
Sometimes I see people saying "in LANG, obj.foo is just 'syntax sugar' for foo(obj)" and I think that technically it has always been "syntax sugar" and there have always been ways to call any "method" with any "object" of any "type."
Sometime along the way we decided that "syntax sugar" means "it means the same thing as" but except for (<cast OtherType>obj).foo(), which means that the semantics of "syntax sugar" don't mean it's simpler than the phrase it was supposed to replace.
> It's not a "property" it's an attribute/field/member/key/column/variable/getter/function/procedure.
For what it's worth, to a researcher in the field of programming languages (like the author of the post), these all have distinct unambiguous meanings. At least as far as PL goes, almost every term has a well-defined meaning, but as those terms were adopted into less-than-academic contexts, the meanings have diluted.
"Property" is such a term in the context of programming languages research, and, in particular, it is a very specifically defined term in the realm of property-based testing (no surprise).
> Even the constants are variables from the viewpoint of the CPU that has to load it in its registers.
No; this is not what "variable" means. Registers are properties of the processor, i.e., they are implementation details; variables are an abstract concept from the domain of the formal language specification.
> Sometime along the way we decided that "syntax sugar" means "it means the same thing as" but except for (<cast OtherType>obj).foo(), which means that the semantics of "syntax sugar" don't mean it's simpler than the phrase it was supposed to replace.
No; this is not what "syntax sugar" means. If a language defines some syntax f and it "expands to" some other syntax g, then f is syntax sugar for g. This is well defined in Felleisen's "On the Expressive Power of Programming Languages" [0]. For example, Python's addition operator `+` is implemented in terms of a method `__add__`; therefore, `a + b` is syntax sugar for `a.__add__(b)`, because the former syntax is built on top of the latter.
Notably, syntax sugar has nothing to do with casts; casts are semantic, not syntactic. There are also no promises about whether syntax sugar makes something "easier"; it's simply the ability to syntactically express something in multiple ways.
[0] direct PDF: https://www2.ccs.neu.edu/racket/pubs/scp91-felleisen.pdf
To a programmer, it's all just memory. Too many people forget that and chase castles in the sky.
The problem is that the same word is used for different things.
The comment you are responding to was correct in what "property" means in some settings.
The article itself says:
> A property is a universally quantified computation that must hold for all possible inputs.
But, as you say,
> but as those terms were adopted into less-than-academic contexts, the meanings have diluted.
And, in fact, this meaning has been diluted. And is simply wrong from the perspective of what it originally meant in math.
You are right that a CPU register is a property of the CPU. But the mathematical term for what the article is discussing is invariant, not property.
Feel free to call invariants properties; idgaf. But don't shit all over somebody by claiming to have the intellectual high ground, because there's always a higher ground. And... you're not standing on it.