[REBOL] Words, Bindings and Contexts. (10)

[lmecir]

My apologies to everybody. The Make-object! and R-make-object!
functions shall be repaired (missing colon before Elem in append
words to word! :elem) The correct versions:

make-object!: func [
    {make object! simulation}
    spec [block!]
    /local words result
] [
    words: make block! 0
    foreach elem spec [
        if set-word? get/any 'elem [
            append words to word! :elem
        ]
    ]
    result: make-context words
    result/self: result
    do bind spec in result 'self
    return get/any in result 'self
]

r-make-object!: func [
    {make object! simulation}
    spec [block!]
    /local words result
] [
    words: make block! 0
    foreach elem spec [
        if set-word? get/any 'elem [
            append words to word! :elem
        ]
    ]
    result: make-context words
    result/self: result
    do bind/copy spec in result 'self
    result
]

{
    here is a code that can behave "unexpectedly":
}

f: func [level] [
    make object! [
        a: 2 * level
        b: either zero? level [
            f 1
        ] [
            none
        ]
        a: a + 1
    ]
]
probe f 0

{
    The results:

>> probe f 0

make object! [
    a: 0
    b: unset
]
}

f: func [level] [
    r-make-object! [
        a: 2 * level
        b: either zero? level [
            f 1
        ] [
            none
        ]
        a: a + 1
    ]
]
probe f 0

{
    The results:

>> probe f 0

make object! [
    a: 1
    b:
    make object! [
        a: 3
        b: none
    ]
]
}