Chalk 📋➕

LL Recursive Descent Parser Interpreted Calculator with support for assignment, boolean logic and much more :)

chalk is my first true dive into creating an interpreter, and as such is a simple starting point. While doing my Discrete Math homework this semester, I've wanted a quick calculator I can pull up to evaluate quick expressions in my terminal and had been running Python's REPL beforehand. As such, I decided to cook up this tiny project as an alternative.

Chalk includes the chalk-core crate that handles tokenization and parsing, alongside chalk which is a CLI tool with two modes of execution:

1. Running chalk with an immediate expression, such as chalk 1 + 1 will evaluate the expression and exit, printing it to standard out

2. If no immediate expression is provided, chalk enters REPL mode and will evaluate expressions until the program is exited

Welcome to the Chalk Repl

->> 1 + 1
`1 + 1` = 2

->> lcm(5!, 12!)
`lcm(5!, 12!)` = 479001600

->> floor(1 - 1/100000) == 0
`floor(1 - 1 / 100000) == 0` = true

->> 10^2 >= 101 || 5! == 120
`10 ^ 2 >= 101 || 5! == 120` = true

->> x = 5
`x = 5` = 5

->> y = x^2
`y = x ^ 2` = 25

->> x = 2
`x = 2` = 2

->> y
`y` = 4

->> 

chalk currently has support for:

• Addition

• Subtraction

• Multiplication

• Division

• Exponentiation

• Operator precedence

• Parenthesis and Absolute value bars

• Unary negation

• Factorial!

• gcd and lcm

• floor and ceil

• Trig functions sin, cos and tan, and their inverses asin, acos and atan

• Extremely simple runtime types system

  • Different operations including factorial, floor, ceil, etc require integers only (and in some cases unsigned only)
  • Enum based type system allows for these assertions and lossless coercions if possible

• Logical operations including Equality and Inequality checks, >, <, >= and <=

• Variable assignment operations with lazy evaluation

If there are any other operations or features you'd like to see, please feel free to make a Pull Request or create an issue :)