Basic Features

Recursive descent parser that builds expression AST. Everything evaluates to an expression which evaluates to a double.

1. Supports +, -, *, / as well as
2. Variable assignment can be done by a=2 or a=b=2.
3. Logical operations like &&, ||
4. Comparison with ==
5. Function definition with `fn fnname(arg1, arg2, ...) { expr1; expr2; returnexpr }
6. Ternary operator cond ? iftrue : iffalse
7. Ans automatic variable to get previous answer
8. Builtin functions: sin(x).

Examples

Simple operations

-4+1*7+2/3
3.666667

Floating point numbers

355/113
3.141593

Variables

> a=b=2
> a+b
4

Logical Operations

> 1 && 2 && 3
1
> 1 && 0
0
> 1 || 0
1

Functions

Last expression is implicitly returned

> fn fib(n) {n==0 || n==1 ? n : fib(n-2)+fib(n-1) }
> fib(10)
55

Todo:

• Units
• Graphing?