https://github.com/mohitk05/arepa
A tiny programming language based on LISP
https://github.com/mohitk05/arepa
interpreter lisp programming-language
Last synced: 19 days ago
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A tiny programming language based on LISP
- Host: GitHub
- URL: https://github.com/mohitk05/arepa
- Owner: mohitk05
- License: mit
- Created: 2022-11-07T23:11:16.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2022-11-16T22:15:50.000Z (over 2 years ago)
- Last Synced: 2025-03-28T03:01:43.792Z (about 1 month ago)
- Topics: interpreter, lisp, programming-language
- Language: TypeScript
- Homepage:
- Size: 16.6 KB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# arepa-lang
`arepa` is a tiny interepreted programming language based on LISP.
To run a program:
```bash
# Install ts-node globally and run
ts-node src/index.ts src/test.arp
```
### Arithmetic
```bash
(+ 10 3) # Output = 13
(* 2 (+ 4 1)) # Output = 10
(/ 100 (/ 25 (+ 2 3))) # Output = 20
```
### Conditionals
Comparisons can be done using the `if` operator
```bash
# Syntax: (if )
# If "condition" is evaluated to true, then execute "true expression"
# and return its value. If it is evaluated to false,
# then execute "false expression" and return its value.
(if 1 2 3) # Output = 2
(if (- 1 1) 2 3) # Output = 3
(if 0 1 (if 1 4 5)) # Output = 4
(if 1 "hello" "goodbye") # Output = "hello"
```
### Lists
Everything in arepa inside a pair of `()` is a list. A list can be a set of any other type.
```bash
(1 2 3 4)
("a" "b" "c")
(1 (1 2) 4)
```
### Functions
Functions are a powerful construct in any language. They can be defined in arepa using the `defunc` operator.
```bash
(
(defunc add (a b) (+ a b)) (add 1 2)
)
# Output = 3
```
As arepa is an interpreted language, the function definition should be before the function call. You can declare multiple functions and construct nested patterns.
```bash
(
(defunc add (a b) (+ a b))
(defunc square (a) (* a a))
(square 2) # Output = 4
(add 2 (square 4)) # Output = 18
(defunc concat_w_space (a b) (+ a " " b))
(concat_w_space "Have" "an" "arepa!") # Output = Have an arepa!
)
```
Recursion is not supported yet (I'll be working on it next!).
Remainder calculation can be done by using an inbuilt operator `re`. This can be used to build functions with conditional bodies.
```bash
(
(defunc even_or_odd (num) (if (re num 2) "odd" "even"))
(even_or_odd 4) # Output = "even"
(even_or_odd 7) # Output = "odd"
)
```