zero_based_indexing

gistfile1.jl

rewrite(x::Number) = x
rewrite(x::Symbol) = x
rewrite(x::String) = x
function rewrite(expr)
    if expr.head == :ref
        return Expr(expr.head, expr.args[1], [rewrite(:( 1 + $i)) for i in expr.args[2:end]]...)
    else
        return Expr(expr.head, [rewrite(i) for i in expr.args]...)
    end
end

macro zero_index(expr)
    eval( rewrite(expr) )
end

@zero_index begin
    a = [67,90]
    b = [0,1]
    c = [ [4 3];[2 5] ]
    x1 = a[0]
    x2 = a[b[1]]
    x3 = c[b[0], 1]
    println( string("\nShould be 67 : ", x1 ))
    println( string("\nShould be 90 : ", x2 ))
    println( string("\nShould be 3 : ", x3 )) 
end

I think you should return the expression without eval. The expression gets evaluated when the function returns anyway. If you use this inside a function you will eval the zero index part only once, and you probably will get errors because of undefined variables.