A Schema inspired, interpreted language written in C#.

• list : ordered, heterogeneous collection
• number : integer or float
• char : a char
• string : list of chars
• function : lambda function

import math

Looks for a file called "math.fun" in the current directory, or a directory called "math" and imports the "main.fun" file from whitin.

import "../math.fun"

Imports the "../math.fun" file.

define a 5 // one number
define (a b c) (4.5 "hey" 6) // a bunch of numbers and strings
define l (3 4 5) // a list
define (l1 l2) ((2 3) (4 "a")) // a bunch of lists

if (== 1 0) then (+ 2 3) else (- 4 5)
if 9 then 4 else 5

An if expression always returns the last element of the list that it evaluated. For example, if 1 (3 4) (9 0) will return 4.

/* comment */

Ignores everything between the marks.

lambda x => (* 2 x)
lambda (x y z) => (+ * x y z)
define f lambda x => (1000 * 2 x)

In order to differentiate between function calls and the function itself, the $ sign is used. As such, if you want to pass the function f as a parameter to another function, use g $f

define f lambda x => (1000 * 2 x)
f 15
(f 15)

A function call can or cannot be surrounded by parantheses. If it is surrounded, it will not be considered a list. In order to create a list with the result of a function call, surround it twice: ((f x)).

A function always returns the last element of the list that it evaluated. For example, f 4 will return 8, even though the list it evaluated turned out to be (1000 8).

Example:

(

define map lambda (f l) => (
	if l then (
		(push f first l map $f rest l)
	) else (
		()
	)
)

define filter lambda (f l) => (
	if l then (
		if (f first l) then (
			(push first l filter $f rest l)
		) else (
			(filter $f rest l)
		)
	) else (
		()
	)
)

println map $lambda x => (+ 5 x) filter $lambda x => (== 0 % x 2) (1 2 5 3 4 5 1 2 3 4 5 6 7 8 5 5 24)

)

This will output (7 9 7 9 11 13 29)

• + a b

• - a b

• * a b

• / a b

  • divides a by b and returns a float (regardless if a and b are integers)

• % a b

  • a and b must be integers

• == a b

• != a b

• > a b

• >= a b

• < a b

• <= a b

• not a

  • negates the logical value of a

• or a b

  • logical or

• and a b

  • logical and

For all operations (apart from modulo), if one of the numbers is a float and the other is an integer, the integer gets promoted to a float. If one of them is a char, it gets converted to its ASCII code.

• push e l : inserts e to the front of l and returns the new list

• append e l : appends e to the end of l and returns the new list

• range n : returns the list (0 1 2 ... n-1)

• println s : prints s to stdout, followed by a new line

• error e : prints e to stderr and halts the program

• readln : reads string from stdin and returns it

• first l : returns the first element of l, error if l is empty

• second l : returns the second element of l, error if l has one element or less

• third l : returns the third element of l, error if l has two elements or less

• last l : returns the last element of l, error if l is empty

• tail l : returns everything after the first element of l (the last n-1 elements), error if l is empty

• head l : returns everything before the last element of l (the first n-1 elements), error if l is empty

• length l : returns the length of l

• empty l : checks if l is empty

• reverse l

• sum l : sums over l

• prod l : multiplies over l

• max a b

• min a b

• map f l : runs f for every element of l and returns the resulting list

• filter f l : runs f for every element of l and returns a list containing the elements for which f is true

• foldl f acc l

• foldr f l acc

• conversations

• implement logical value for Expression

• implement ordering

• implement imports

• reformat code

• make error reporting work with tabs

• fix line counting when reporting errors

• add support for special chars ('\n')

• improve printing

• make functionator work with FCallable?