Camel

Camel is an interpreted programming language written entirely in Go without use of any third-party libraries. It uses pratt parsing to create AST (abstract syntax tree). Evaluation is done simply by walking the tree. It is supposed to be simple and easy to understand. Read Acknowledgements for more information.

Installation

Download repl at /bin to run the interpreter.

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Hello! mehrdad, This is camel programming language!
Feel free to type in commands
>> 

Variables

Camel is dynamically-typed. Decalare variables using beza keyword.

>> beza x = 2 
>> beza y = "name" 
>> beza t = true 
>> x + 3 
5
>> !t 
false 
>> t == (1 < 2) 
true
>> "name" + " : " + "Monica" 
name : Monica 

Array

>> beza x = [1 , 2 , "hey", true]
>> x[5 - 3*2 + 1] + x[1] 
3

Hash

>> beza x = {"lang": "camel" , "version": 0.0}
>> x["lang"] 
camel

Builtins

>> beza x = [1 , 2 , "hey", true]
>> len(x)
4 
>> peek(x) 
true 
>> pop(x) 
[1, 2, "hey"] 

Condition

if ( 2 - 4 < 0 ) {
  2 
} else { 
  bede 1 
}

Note that you can choose to write bede or skip. same goes with semicolons. bede is a keyword used to return values.

Function

keyword for functions are foo & bar. use any of these two to define a function.

beza fib = foo(x) { 
  if (x == 0) {
    0
  } else {
    if (x == 1) {
      bede 1;
    } else {
      fibonacci(x - 1) + fibonacci(x - 2);
    }
  }
};

Closure

>> beza newAddr = foo(x) { bar(c) { x + c } }
>> beza addTwo  = newAddr(2)
>> addTwo(5) 
7
>> newAddr(2)(5) 
7

Errors

>> beza x = 2 
>> x()
Error: Invalid function call, INTEGER is not a function
>> beza x = [1 , 2] 
>> x[4]
Error: Index out of range
>> x["hey"] 
Error: Invalid Index: index operator not supported for type ARRAY
>> 2 == true
Error: Type mismatch: invalid operator == for types INTEGER BOOLEAN

TODO

• Add support for bitwise operators
• Add support for logical operators
• Add support for modulo operators
• Add support for emojis
• Resolve hash collisions
• Scanning input
• Add support for comments
• Add support for control characters
• Add support for loops
• Add support for error handling in parser

Acknowledgement

The Camel programming language is highly based on Monkey. Moneky is an educational programming language first presented in the book "Writing an interpreter in Go". Camel was built following instructions of the book. You can find more information here.