I'm trying to do some morse code, but I'm struggling to work out the start
position of the 'dit' and the 'dah'... I think first, the code...

id=1;wt=1; // for a ring, don't worry about these
lu = 1; // letter unit. a dit is 1 unit wide, a dah is 3, and the gap
between them is 1.
module drawChar(s) {
echo("char: ", s);
pos = 0;
for(i = [0:len(s)-1]) {
inc = 0;
if(s[i] == ".") {
echo(s[i], "dit ",pos," ", inc);
translate([pos+lu/2,0,0]) cylinder(r=lu/2, h = (id+wt+2)/2);
inc = (1 + 1)lu;
} else if(s[i] == "-") {
echo(s[i], "dah ",pos," ", inc);
translate([pos,-lu/2,0]) cube([3lu,lu,(id+wt+2)/2]);
inc = (3+1)*lu;
}
pos = pos + inc; // the inc seems to have gone out of scope
}
}
drawChar("--.-"); // this is a 'q'

This is the output:

ECHO: "char: ", "--.-"
ECHO: "-", "dah ", 0, " ", 4
ECHO: "-", "dah ", 0, " ", 4
ECHO: ".", "dit ", 0, " ", 2
ECHO: "-", "dah ", 0, " ", 4

I have tried many ways to calculate 'pos' - the starting point of the
dit/dah. So the bit that's getting me is the way assignments seem to work -
basically pos always stays zero. Also at the point of echoing inc, I'm
expecting it to still be zero.

2 questions I suppose, a learning point for me, what's going on? and second,
how do I make it do what I want it to do?

I was thinking of some way to count the occurances of '.' and '-' in the
array as a function multiplying accordingly, but my brain melted a little -
it is early.

Any help much appreciated
Nigel

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For info, here is my recursive position counter that fails:

function cpos(s, n) = cpos(s,n-1) + (n == -1) ? (0) : ( (s[n]==".") ? 2 :
4);

when I use it instead of pos in the x coordinate for example in the dit:

translate([cpos(s,i)+lu/2,0,0]) cylinder(r=lu/2, h = (id+wt+2)/2);

it says recursion detected. It's not lying  but the manual says I can do
recursion with the trigraph stuff.

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Doh!!! yep.

I moved the conditional calling, but this is still not playing nicely:

function cpos(s, n) = (n == -1) ? (0) : ( cpos(s,n-1) + (s[n]==".") ? 2 : 4
);

echo ("--.-, 0: ", cpos("--.",0));
echo ("--.-, 1: ", cpos("--.",1));
echo ("--.-, 2: ", cpos("--.",2));
echo ("--.-, 3: ", cpos("--.",3));

ECHO: "--.-, 0: ", 4
ECHO: "--.-, 1: ", 4
ECHO: "--.-, 2: ", 4
ECHO: "--.-, 3: ", 4

I have also noticed a problem in that 0 should be 0 which I'll fix later,
but that aside, I would expect the following

ECHO: "--.-, 0: ", 4
ECHO: "--.-, 1: ", 8
ECHO: "--.-, 2: ", 10
ECHO: "--.-, 3: ", 14

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Sorry, yep, I'm using the latest release 2015.03 on both mac and windows

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Yep, I'm now using recursion to bypass that :) but it seems I'm a bit rusty
at that as well.

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Yeah I'm not doing that any more because it doesn't work. I've moved to
recursion. Possibly an email lag?

This is what is now not working:

function cpos(s, n) = (n == -1) ? (0) : ( cpos(s,n-1) + (s[n]==".") ? 2 : 4
);

cpos("--.-",3) returns 4, instead of 14.

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