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# .tlv file generated by https://github.com/akkartik/teliva
# You may edit it if you are careful; however, you may see cryptic errors if you
# violate Teliva's assumptions.
#
# .tlv files are representations of Teliva programs. Teliva programs consist of
# sequences of definitions. Each definition is a table of key/value pairs. Keys
# and values are both strings.
#
# Lines in .tlv files always follow exactly one of the following forms:
# - comment lines at the top of the file starting with '#' at column 0
# - beginnings of definitions starting with '- ' at column 0, followed by a
# key/value pair
# - key/value pairs consisting of ' ' at column 0, containing either a
# spaceless value on the same line, or a multi-line value
# - multiline values indented by more than 2 spaces, starting with a '>'
#
# If these constraints are violated, Teliva may unceremoniously crash. Please
# report bugs at http://akkartik.name/contact
- __teliva_timestamp: original
menu:
>-- To show app-specific hotkeys in the menu bar, add hotkey/command
>-- arrays of strings to the menu array.
>menu = {}
- __teliva_timestamp: original
Window:
>Window = curses.stdscr()
- __teliva_timestamp: original
doc:blurb:
>To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
>
>You can also override the default big picture screen entirely by creating a buffer called 'doc:main'.
- __teliva_timestamp:
>Sat Feb 26 21:50:11 2022
main:
>function main()
> local c = task.Channel:new()
> task.spawn(counter, c)
> for i=1,10 do
> print(c:recv())
> end
>end
- __teliva_timestamp:
>Sat Feb 26 21:50:11 2022
__teliva_note:
>a simple counter
counter:
>function counter(c)
> local i = 2
> while true do
> c:send(i)
> i = i+1
> end
>end
- __teliva_timestamp:
>Sat Feb 26 21:54:53 2022
filter_task:
>function filter_task(p, cin, cout)
> while true do
> local i = cin:recv()
> if i%p ~= 0 then
> cout:send(i)
> end
> end
>end
- __teliva_timestamp:
>Sat Feb 26 21:55:46 2022
main:
>function main()
> local primes = task.Channel:new()
> task.spawn(sieve, primes)
> for i=1,10 do
> print(primes:recv())
> end
>end
- __teliva_timestamp:
>Sat Feb 26 21:59:37 2022
__teliva_note:
>filter out multiples of a single number
sieve:
>function sieve(ch)
> local iota = task.Channel:new()
> task.spawn(counter, iota)
> task.spawn(filter_task, 2, iota, ch)
>end
- __teliva_timestamp:
>Sat Feb 26 22:08:07 2022
__teliva_note:
>implement the complete sieve algorithm
sieve:
>-- Set up a Sieve of Eratosthenes (https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
>-- for computing prime numbers by chaining tasks, one per prime.
>-- Each task is responsible for filtering out all multiples of its prime.
>function sieve(primes_ch)
> local c = task.Channel:new()
> task.spawn(counter, c)
> while true do
> local p, newc = c:recv(), task.Channel:new()
> primes_ch:send(p)
> task.spawn(filter_task, p, c, newc)
> c = newc
> end
>end
- __teliva_timestamp:
>Sat Feb 26 22:09:47 2022
__teliva_note:
>infinite primes
main:
>function main()
> local primes = task.Channel:new()
> task.spawn(sieve, primes)
> while true do
> Window:addstr(primes:recv())
> Window:addstr(' ')
> Window:refresh()
> end
>end
- __teliva_timestamp:
>Sat Feb 26 22:09:47 2022
__teliva_note:
>clear screen when it fills up; pause on keypress
>
>In Teliva getch() implicitly refreshes the screen.
main:
>function main()
> Window:nodelay(true)
> Window:clear()
> local primes = task.Channel:new()
> task.spawn(sieve, primes)
> local h, w = Window:getmaxyx()
> while true do
> Window:addstr(primes:recv())
> Window:addstr(' ')
> local c = Window:getch()
> if c then break end -- key pressed
> local y, x = Window:getyx()
> if y > h-1 then
> Window:clear()
> end
> end
> print('key pressed; done')
> Window:nodelay(false)
> Window:getch()
>end
- __teliva_timestamp:
>Sat Feb 26 22:27:25 2022
doc:blurb:
>Sieve of Eratosthenes
>https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
>
>A demonstration of tasks and channels, the primitives for (cooperative) concurrency in Teliva.
>
>We string together a cascade of tasks connected by channels. Every prime number gets a new task that prints the first incoming number, and then filters out multiples of it from the incoming channel.
>
>This approach has the advantage that we don't need to create an array of n numbers to compute primes less than n.
>
>However, we still need to create p tasks and p channels if there are p primes less than n. Probably not worth it, given tasks and channels are much larger than numbers. This is just a demo.
>
>The noticeable periodic pauses are perhaps due to garbage collection.
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