Rule: comprehension-term-assignment

[anderseknert]

Somewhat similar to the unconditional-assignment rule, and also in the style category. I think it would be good to have Regal help simplify comprehensions where the last expression is a simple assignment to a term variable, and suggest moving the value directly to the comprehension head instead.

Avoid

to_string(ref) := concat(".", [path |
    some part in ref
    path := part.value
])

Prefer

to_string(ref) := concat(".", [part.value | some part in ref])

Note that while it's often possible to move a lot of code in that direction, like function calls — I don't think that helps readability at all, and so we should stick to recommend this for simple assignment like the example shown above.

[anderseknert]

Renamed from "tail" assignment to "term" assignment, as detecting simple assignment of a term var elsewhere involves the same check more or less, just peformed over all the expressions. So something like this should be flagged just the same:

Avoid

to_string(ref) := concat(".", [path |
    some part in ref
    path := part.value
    part.type == "string"
])

Prefer

to_string(ref) := concat(".", [part.value |
    some part in ref
    part.type == "string"
])