0mmk / tinylang

A Tiny Programming Language

TinyLang

A tiny programming language that is inspired by Lisp with very minimal binary form that doesn't make things complicated overtime - function definitions and calls. :))

Developer: Mehmet Melih Karakaya <20190808067>

Running instructions:

make

Running tests

make test

Syntax Explanation

Syntax explanation and examples are given in test.tinylang file as well

• Has if for conditional execution
• Variable assigment and declaration
• Has function definitions and calls
  • but that would require complex yacc with AST :(
    • Yay! Done. However I had to remove some complexity of my language.
• Blocks for statements like while, if, functions...
• Integer declaration without requireing a keyword for assignments.

Design Decisions

• I didn't wanted to make this programming language really complex bcs I had ran into this issue before, an overly complicated syntax, making it harder for one person to manage and understand the behavior of semantics.
  • I didn't take PL Class before but had interest in this area, see: https://github.com/0mmk/calc
    • (it's not a programming language, it's a really bad calc that I made in my first year at Uni), so I was familiar with lexers and other tools bcs I understood my calc sucks. But I wasn't completely dived into lexers, now I'm.
  • However I wish I knew lex/yacc or other tools preferably so good that I can create a PL that proofs memory safety just like Rust.
• In fact, I've removed some of the complex stuff from my older version attempts in order to write a "properly working" language interpreter.

Click to see the explanation

### Note: Because the language is inspired by Lisp, I've used lisp syntax highlighting for better readability.

// comment

// printing string
(print "----------------------------")
(print "Every string is a multiline string

Line 1
Line 2
Line 3")
(print "----------------------------")

(print "Assigning Variable 'x': 5, 10, 50")

// variable assignment
(= x 5) // becomes 1

// variable assignment #2
(= x (+ x 5)) // becomes 10

// variable assignment #3
(= x (* 10 5)) // becomes 50

// printing variables/numbers
(print x)
(print "Printing literal int constant 3: ")
(print 3)

(print "----------------------------")

(print "Printing complex expression 2 + 5 / 2 * 3")

// complex expression 2 + 5 / 2 * 3
(print (+ 2 (* (/ 5 2) 3)))

(print "----------------------------")

// while loop printing from 50 to 1
(print "Printing numbers from 50 to 1: ")

(while (!= x 0)
  (
    (print x)
    (= x (- x 1))
  )
)

(= x 0)
// while loop, dummy iteration 100000 times
(while (!= x 100000)
  (= x (+ x 1))
)

// if statement, insider block won't execute
(= x 10)
(if (> x 10) 
  (
    (print "This will not execute!
    This will not be seen!
    This will not exist!")
  )
)

(print "----------------")

// if statment, insider block will execute
(if (?= x 10) (print "This will be seen!"))

(print "----------------")
(print "Printing numbers to show combined statements")
// combined statements
// functions like if, while, def and only takes one argument for execution, which is block
(if (< x 100)
  (print x)
)
// however a block can have multiple blocks inside of it, for example
(if (< x 100) (
    (print x)
    (print x)
  )
)


// function definition with loop, assigments and operations
(def f (
    (while (> n 0) (
        (= a b)
        (= b c)
        (= c (+ a b))
        (= n (- n 1))
      )
    )
    (print a)
  )
)

// function definition (recursive)
(def r (
    (if (?= n 0) (print a))
    (if (!= n 0) (
        (= a b)
        (= b c)
        (= c (+ a b))
        (= n (- n 1))
        (call r)
      )
    )
  )
)

(print "----------------------------")

// function call
// it doesn't matter if it's one line or many lines
(print "Fibonacci(12) Imperative: ")
(= n 12) (= a 0) (= b 1) (= c 1)
(call f)

// function call
(print "Fibonacci(12) Recursive:  ")
(= n 12) (= a 0) (= b 1) (= c 1)
(call r)

(print "----------------------------")

Click to see the output

----------------------------
Every string is a multiline string

Line 1
Line 2
Line 3
----------------------------
Assigning Variable 'x': 5, 10, 50
50
Printing literal int constant 3: 
3
----------------------------
Printing complex expression 2 + 5 / 2 * 3
8
----------------------------
Printing numbers from 50 to 1: 
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
----------------
This will be seen!
----------------
Printing numbers to show combined statements
10
10
10
----------------------------
Fibonacci(12) Imperative: 
144
Fibonacci(12) Recursive:  
144
----------------------------

Design Decisions

BNF Form

<start> : <prog> <start>
          | <expr> <start>
          | 
          ;

<prog>  : '(' <comb> ')'
          | '(' 'print' <expr> ')'
          | '(' 'print' <string> ')'
          | '(' '=' <variable> <expr> ')'
          | '(' 'while' <expr> <prog> ')'
          | '(' 'if' <expr> <prog> ')'
          | '(' 'def' <variable> <prog> ')'
          | '(' 'call' <variable> ')'
          ;

<comb>  : <comb> <prog>
          | <prog>
          ;

<expr>  : <string>
          | <variable>
          | '(' <math> ')'
          ;

<math>  : '+' <expr> <expr>
          | '*' <expr> <expr>
          | '-' <expr> <expr>
          | '/' <expr> <expr>
          | '<' <expr> <expr>
          | '>' <expr> <expr>
          | '?=' <expr> <expr>
          | '!=' <expr> <expr>
          ;

<integer> : [0-9]+
<variable> : [a-zA-Z]+
<string> : ".*"