Punnet Square Maker (CC)

term.clear()
term.setCursorPos(1,1)

    pat = read() --paternal --localize
    mat = read() --maternal --localize

pat = pat:sub(1,#pat-(#pat%2))
mat = mat:sub(1,#mat-(#mat%2))

split = function(txt,splitPt) --such a useful function
    local output = {}
    local buffer = ""
    for a = 1, #txt do
        if (txt:sub(a,a) == "\n") or (#buffer >= splitPt) then
            output[#output+1] = buffer
            buffer = ""
        end
        buffer = (buffer..txt:sub(a,a)):gsub("\n","")
        if a == #txt then
            output[#output+1] = buffer
        end
    end
    return output
end

everyOther = function(txt,step) --localize
    local output = ""
    for a = 1, #txt, step or 2 do
        output = output..txt:sub(a,a)
    end
    return output
end

foilArrange = function(str,step)
    step = step or 2
    local output = {}
    local genes = split(str,2)
    for g = 1, #genes do
        for a = 1, #genes[g] do
            for b = 1, #genes[g] do
                if a ~= b then
                    output[#output+1] = genes[g]:sub(a,a)..genes[g]:sub(b,b)
                end
            end
        end
    end
    return output
end

spliceStr = function(txt1,txt2) --localize
    assert(#txt1 == #txt2, "strings must be same length, you dullard")
    local output = ""
    for a = 1, #txt1 do
        output = output..txt1:sub(a,a)..txt2:sub(a,a)
    end
    return output
end

    pGenes = foilArrange(pat) --localize
    mGenes = foilArrange(mat) --localize

    grid = {} --localize

for p = 1, #pat do
    grid[p] = {}
    for m = 1, #mat do
        grid[p][m] = spliceStr(pGenes[p],mGenes[m])
    end
end

writeBlocks = function(len,col) --localize
    local pCol = term.getBackgroundColor()
    term.setBackgroundColor(col or colors.white)
    term.write((" "):rep(len or 1))
    term.setBackgroundColor(pCol)
end

renderGrid = function(g,sx,sy)
    sx, sy = sx or 2, sy or 2
    term.setCursorPos(sx,sy)
    writeBlocks(1+((#g[1])^2)+#g[1])
    for y = 1, #g do
        term.setCursorPos(sx,sy+(y*2)-1)
        writeBlocks(1)
        for x = 1, #g[y] do
            term.write(grid[y][x])
            writeBlocks(1)
        end
        term.setCursorPos(sx,sy+(y*2))
        writeBlocks(1+((#g[1])^2))
    end
end

local cx,cy = term.getCursorPos()

renderGrid(grid,2,cy+2)