A Lisp implementation in C

Xcode (an OS X specific coding tool)

$  xcode-select —install

Homebrew (a package manager that lets you install stuff you need for coding that is not already on you computer like programming languages)

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”

Git

$  brew install git

Downloads code from github onto your computer

$ git clone https://github.com/nliolios24/lioliosh

Compiles the c code into an executable

$ cc -std=c99 -Wall repl.c mpc.c -ledit -lm -o lioliosh

Runs the repl

./lioliosh

Builtin functions are predefined and operate on a list of arguments. If you have a builtin function named foo that you could evaluate with the arguments bar, '(bar baz) and '(bar (baz bar)), then the following code will perform the operation and return its output.

>>> foo bar '(bar baz) '(bar (baz bar))

To define a variable

>>> def '(x y) 1 2

To create a function that takes input x

>>> fn '(cube z) '(^ x 3)

To call a function

>>> cube y
8

The supported math functions are:

+ - * / % ^

They each take one or more arguments.

The Supported comparison functions are:

== != > < >= <=

They each take two arguments.

If takes three arguments, a condition and two quoted expressions. If the condition is nonzero, then the first quoted expression is evaluated. Otherwise, the second is evaluated.

>>> if (5) '(10) '(2)
2

List takes n arguments are returns a quoted expression.

>>> list 1 2 3
'(1 2 3)

Eval takes a quoted expression and returns n arguments.

>>> eval '(1 2 3)
1 2 3

Head returns the first element of a quoted expression

>>> head '(1 2 3)
'(1)

Tail returns a quoted expression all but the first element of a quoted expression.

>>> tail '(1 2 3)
'(2 3)

Join joins two quoted expressions.

>>> join '(1 2) '(3 4)
'(1 2 3 4)

Min returns the smallest element in a quoted expression.

>>> min '(1 2 3)
1

Max returns the largest element in a quoted expression.

>>> max '(1 2 3)
3

Cons prepends an atom to a quoted expression to return a quoted expression.

>>> cons 1 '(2 3 4)
'(1 2 3 4)

Len takes a quoted expression and returns its length.

>>> len '(1 2 3 4)
4

Pop takes a quoted expression and returns everything but the last element.

>>> pop '(1 2 3 4)
'(1 2 3)

Last takes a quoted expression and returns the last element.

>>> last '(1 2 3 4)
4

Nth takes a quoted expression and a number and returns the nth element.

>>> nth 2 '(1 2 3 4)
3

Drop takes a number and a quoted expression and returns a quoted expression with the first n elements removed.

>>> drop 2 '(1 2 3 4)
'(4)

Take takes a number and a quoted expression and returns the first n elements.

>>> take 2 '(1 2 3 4)
'(1 2)

Elem takes a number and quoted expression and chacks if the number is in the quoted expression. If it is it outputs one, and if it isn't it outputs zero.

>>> elem 5 '(1 2 3 4)
0

Not takes a number and returns false if the number is zero and true if the number is not zero.

>>> not 5
true

All takes a quoted expression and returns true if all numbers in the quoted expression are not zero and false if any are zero.

>>> all '(1 2 0 3)
false

Any takes a quoted expression and returns true if any numbers in the quoted expression are not zero and false if all of the numbers are zero.

>>> any '(0 0 1 2)
true