The Grammar According to West

I found this interesting. SQL and Swift use “where” for restrictions. Any other examples in programming languages?

If a programming language wanted to use a keyword for restrictions that isn’t “where” (and still is a single word, hence “such that” doesn’t qualify), what word would be suitable instead? “With”? “Having”?

As for single-word alternatives, "if" is common. For example, in Python:

    >>> [(x, y) for x in range(10) for y in range(2, x) if x % y == 0]
    [(4, 2), (6, 2), (6, 3), (8, 2), (8, 4), (9, 3)]

    * (loop for x from 1 to 100 when (= x (expt (floor (sqrt x)) 2)) collect x)
    (1 4 9 16 25 36 49 64 81 100)

    DB<4> for (1..10) { print "$_ " unless $_ == int($_**.5)**2 }
    2 3 5 6 7 8 10

    struct S
    {
        x : num;
        y : num;
        where x < y
    }

    struct S
    {
        x : num;
        y : num;
    }

    let s : S where s.x < s.y;

"If" wouldn't fit that use case, and neither would "when". I suppose "require" would work, but it also feels different from "such that". The intended meaning of the latter example would be "let s be an S such that s.x < s.y". "Given", as the sibling comment by hallole proposes, also doesn't fit.