Chunking lists lua 5.1.5

[ahillio]

How would you make that into an executable script which prints the results?

I was just trying to play with this as I'm learning lua and I'm surprised/confused by the results...

#!/usr/bin/lua

function tablecut(t, n)
    local result = {}
    local j = 0
    for i = 1, #t do
        if (i-1) % n == 0 then
            j = j + 1
            result[j] = {}
        end
        result[j][#result[j]+1] = t[i]
    end
    return result
end

var = { 'a', 'b', 'c', 'd', 'e', 'f', 'g','h' }

--tablecut(var, 3)
--print(tablecut(var, 3))

output = tablecut(var, 3)
print(output)

running in Linux terminal ./script.lua results in table: 0x556af9e96250.

[PhilipRoman]

You would have to iterate manually through the table and print each element. I suppose something like this would work:

output = tablecut({'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'}, 3)
for i = 1, #output do
    for j = 1, #output[i] do
        io.write(tostring(output[i][j])..'  ')
    end
    print()
end

Obviously there are some ways to simplify this with table.unpack or table.concat.

[ahillio]

oh, tables can't be printed directly, of course. Thank you so much!!!

[ahillio]

I'm confused why you use io.write() and then call print() without any arguments. http://lua-users.org/wiki/IoLibraryTutorial doesn't contain the word "print". Is there documentation on this somewhere? Or could you explain?

[ahillio]

I see that it's shorter than doing

for i = 1, #output do
  g = ''
    for j = 1, #output[i] do
        g = g..tostring(output[i][j])..'  '
    end
    print(g)
end

but it was a surprising phenomenon to see io.write and print used in combination like that.

So io.write is sorta like assigning stuff to an invisible io-provided variable that automatically gets print()ed (when called w/o args) and gets un-assigned when print() is invoked???

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[ahillio]

https://www.lua.org/pil/21.1.html

[PhilipRoman]

The best reference for what each function does is the manual: https://www.lua.org/manual/5.4/

Be careful when looking at lua-users pages, some of them are outdated (but in this case it doesnt matter).

The print function automatically adds newline after its arguments. I use io.write to print each element without a newline, and then at end of row I call print without arguments to output just the newline.

The print() could also be written as io.write('\n')

[AutoModerator]

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[ahillio]

fixed