Lysithea Scripting Language

Overview

A handle of basic examples of the Lysithea scripting language running in the browser. Check out the repository for more details.

There are two Unity examples as well, both of these can be found in the repository as well:

Drawing: Example of creating elements.
Dialogue: Example of a game dialogue system.

Note: While these work on mobile, they are definitely not mobile optimised and currently there is an issue with input fields and mobile keyboards.

Simple Example

Includes the standard library.

A simple example of creating a function and running it.

Code Input

(function main()
    (print (+ 5 12))
)
(main)

Console Output

Loop Example

Includes the standard library.

A simple example looping example.

Code Input

(define i 0)
(loop (< i 4)
    (print i)
    (++ i)
)
(print "Done")

Console Output

Performance Test

Includes the standard library with a rand functions.

A basic performance test, the main thing this is testing is calling functions from outside of the VM. Ideally this should not take longer than 1 second to run.

Code Input

; A simple performance test script.
(function step ()
    (return (+ (rand) (rand)))
)

(function main ()
    (define total 0)
    (define counter 0)

    (loop (< counter 1000000)
        (+= total (step))
        (++ counter)
    )

    (print "Done: " total)
)

(main)

Console Output

Conditionals

Includes the standard library with a function for getting user input, waiting and random number.

An example of how conditionals work and how they can be used as expressions too. Note that there is a deliberate delay between prompts otherwise you would not see the output in the console.

Code Input

(:Start)
(define name (prompt "What is your name?"))
(print "You entered " name)
(if (== name null)
    (jump :End)
)

(if (== name.length 0) (
    (set name (if (> (rand) 0.5) "Fred" "Fredrika"))
    (print "All good, I'll come up with a name, how about " name "?")
    (wait 1500)
))

(print "Hello " name)
(print (if (> (rand) 0.5) "It's a fine day" "It's a good day"))

(wait 2000)

(:Options)
(define input (prompt "Choose an option:
- 1: Hello
- 2: Who are you?
- 3: Can I have a new name?
- 4: Good bye"))

(switch
    ((== input "1")
        (print "Hello there! How are you " name "?")
        (wait 2000)
        (jump :Options)
    )
    ((== input "2")
        (print "You see " name ", I'm just a text box")
        (wait 2000)
        (jump :Options)
    )
    ((== input "3")
        (jump :Start)
    )
    ((|| (== input "4") (== input null))
        (print "See ya late " name)
        (jump :End)
    )

    (true
        (print "I don't know that option")
        (jump :Options)
    )
)

(:End)

Console Output

Page Set

Includes the standard library with setBackground, setTheme and random functions.

A somewhat contrived example of adding some extra functions for interacting with the page.

In this example there are two extra functions setBackground and setTheme.

setBackground has three inputs purple, grey and green.

setTheme has two inputs light and dark.

random.pick takes a list of arguments and will randomly return one of the values.

Code Input

(define background (random.pick "purple" "green" "grey"))
(define theme (random.pick "light" "dark"))

(print "Setting background to: " background)
(print "Setting theme to: " theme)

(setBackground background)
(setTheme theme)

Console Output