[julia-users] invalid assignment location

[andrew cooke]

Hi,

What does --- ERROR: syntax: invalid assignment location "(:: i Uint)" --- 
mean?  I think it may be from the lisp/scheme layer which would explain the 
strange position of "i", but I am having a hard time working out where the 
mistake is in my ugly code (the location info is useless).

The error is likely in:

function precalc1()
    function calc(state)
        a = state & 0x01; state = state >> 1
        b = state & 0x01; state = state >> 1
        ac = state & 0x01; state = state >> 1
        bc = state & 0x01; state = state >> 1
        s1 = state & 0x01; state = state >> 1
        s2 = state & 0x01; state = state >> 1
        s3 = state & 0x01; state = state >> 1
        s4 = state & 0x01; state = state >> 1
        a = a $ b
        a = a + s1
        b = b $ a
        b = b + s2
        convert(Uint8, (a & 0x01) | (b & 0x01) << 1 | (a & 0x02) << 1 | (b & 
0x02) << 2)
    end
    cache = zeros(Uint8, 0x100)
    for i::Uint in 0x0:0xff
        cache[i+1] = calc(i)
    end
    cache
end


function precalc2(cache1)
    cache = zeros(Uint8, 0x4000)
    for in1::Uint in 0:0xff  # ab2, r1c2, r1s4                             
     
        out1 = cache1[in1+1]
        for cs::Uint in 0x0:03f  # r2c2, r2s4                               
    
            in2 = (out1 & 0x03) | (cs << 2)
            out2 = cache[in2+1]
            # construct  ab2, r1c2, r2c2, r1s4, r2s4                       
     
            in = (in1 & 0x0f) | (cs & 0x03) << 4 | (in1 & 0xf0) << 2 | (cs & 
0x3c) << 8
            # construct  final result + all carries                         
    
            out = convert(Uint8, (out2 & 0x03) | (out1 & 0x0c) | (out2 & 
0x0c) \
<< 2)
            cache[in+1] = out
        end
    cache
end


function precalc3(cache1, cache2)
    cache = zeros(Uint8, 0x100000)
    for in1::Uint in 0x0:0xff  # ab2, r1c2, r1s4                           
     
        out1 = cache1[in1+1]  # ab2, r1c2                                   
    
        for cs::Uint in 0x0:0xfff  # r2c2, r3c2, r2s4, r3s4                 
    
            in2 = (out1 & 0x03) | (cs << 2)
            out2 = cache2[in2]  # ab2, r2c2, r3c2                           
    
            # construct  ab2, r1c2, r2c2, r3c2, r1s4, r2s4, r3s4           
     
            in = (in1 & 0x0f) | (cs & 0x0f) << 4 | (in1 & 0xf0) << 4 | (cs & 
0xff0) << 8
            # construct  ab2, r1c2, r2c2, r3c2                             
     
            out = convert(Uint8, (out2 & 0x03) | (out1 & 0x0c) | (out2 & 
0x3c) \
<< 2)
            cache[in+1] = out
        end
    end
end


function encrypt_bit()
    const cache1 = precalc1()
    const cache2 = precalc2()
    const cache3 = precalc3()
end


and any suggestions on how to write that kind of bit-twiddling neater (but 
no less efficiently) welcome.

Thanks,
Andrew