Locals are a leaky abstraction. The leaks should be fixed as much as possible.

Open problems

Locals also don't work with undo. On the left hand side, they should bind locals.

There is still an issue with locals and fry:

[ 10 ] [
    0 '[ [let | A [ 10 ] | A _ + ] ] call .
] unit-test

Fixed

Locals and macros which treat quotations as sequences

:: (funny-macro-test) ( obj quot -- ? ) { quot } 1&& ; inline
: funny-macro-test ( n -- ? ) [ odd? ] (funny-macro-test) ;

\ funny-macro-test must-infer
[ t ] [ 3 funny-macro-test ] unit-test
[ f ] [ 2 funny-macro-test ] unit-test

! Fry and locals

[ 10 ] [
    [let | |
        0 '[ [let | A [ 10 ] | A _ + ] ] call .
    ]
] unit-test

! Smart combinators and wlet

:: wlet-&&-test ( a -- ? )
    [wlet | is-integer? [ a integer? ]
            is-even? [ a even? ]
            >10? [ a 10 > ] |
        { [ is-integer? ] [ is-even? ] [ >10? ] } &&
    ] ;

[ f ] [ 1.5 wlet-&&-test ] unit-test
[ f ] [ 3 wlet-&&-test ] unit-test
[ f ] [ 8 wlet-&&-test ] unit-test
[ t ] [ 12 wlet-&&-test ] unit-test