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Lexical Binding

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In GXScript, I have renamed “def”, “load”, “store” and “where” to “ddef”, 
“dload”, “dstore” and “dwhere” (“d” for “dynamic”) and added corresponding 
lexically-bound variants “ldef”, “lload”, “lstore” and “lwhere”. In 
effect, GXScript is a “block-structured” language.

Example:

    /Count 99 ddef

    {
        /Count 1 ldef
            3
            {
                /Count dup lload 1 add lstore
                (local Count = ) print /Count lload =
                (global Count = ) print /Count dload =
                (whichever Count = ) print Count =
            }
        repeat
    } exec

produces output

    local Count = 2
    global Count = 99
    whichever Count = 2
    local Count = 3
    global Count = 99
    whichever Count = 3
    local Count = 4
    global Count = 99
    whichever Count = 4

and you can define function factories, e.g.

    /Count 99 ddef

    /metatry
        { # provides context for nonlocals
            dup
            /Name exch ldef
            /Count 0 ldef
            { # actual proc
                /Count dup lload 1 add lstore
                /Count dup dload 1 add dstore
                Name =
                (local Count = ) print /Count lload =
                (global Count = ) print /Count dload =
                (whichever Count = ) print Count =
            }
        }
    ddef

    /try1 metatry ddef
    /try2 metatry ddef

    try1
    try2
    try1
    try2

produces output

    try1
    local Count = 1
    global Count = 100
    whichever Count = 1
    try2
    local Count = 1
    global Count = 101
    whichever Count = 1
    try1
    local Count = 2
    global Count = 102
    whichever Count = 2
    try2
    local Count = 2
    global Count = 103
    whichever Count = 2

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Lexical Binding Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-04 05:59 +0000

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