Dwarf

Dwarf is a very small scripting language that will ease concurrency. The syntax of Dwarf is heavily influenced by programming languages like Go and OCaml.

Dwarf-Interpreter

The interpreter for dwarf is written in Elixir.

To interpret a source program run

mix escript.build 		# in the main folder
# this will generate an executable dwarf file
./dwarf path-to-file.dw     # this will start the interpretition of the script

The "main" function is declared in lib/cli.ex

Language description

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To see some examples of programs written in Dwarf, look inside the folder /benchmarks/*.dw

The language will have very simple operations and expressions. Here is the CFG specification in BNF of the parser of Dwarf,

stmt ::=  
	| `if` expr `then` stmt `else` stmt         --- if expr then statement else statement
	| 'fun' ident ':=' '(' params ')' '->' stmt --- declaration of  a function
	| type ident '=' expr                       --- assignment such as `a = 3 + 2` where a has already been declared
	| type ident ':=' expr                      --- declaration and assignment of a new variable `int a := 3 + 2`
	| '{' stmts '}'                             --- a list of statements
	| 'print' ident                             --- print a value to the command line
	| 'while' expr 'do' stmt                    --- a typical while statement

expr ::= 
	| op <> expr                 --- concatenation of two string
	| op
op ::=  
	| term + op                  --- addition
	| term - op                  --- substraction
	| term > op                  --- greater than
	| term >= op                 --- greater or equal
	| term < op                  --- smaller than
	| term <= op                 --- smaller or equal
	| term == op                 --- equality 
	| term
	   
term ::= 
	| factor * term               --- multiplication
	| factor / term               --- division
	| factor % term               --- modulo
	| factor

factor ::= 
	| `true`, `false`             --- booleans
	| number                      --- integer such as `7`,`8`,`9` no floats yet
	| var                         --- a variable such as a, foo, etc
	| function call = foo(args)   --- `get()`, `square(3)"`
	| (expr)                      --- bracketed expression `(2 + 3) * 2`
	| unary operation             --- "!"

args ::= 
	| list of expr (expr,expr)     --- arguments passed to a function call
	| expr

params ::= 
	| type identifier            --- a parameter of a function declaration
	| type identifier','params   --- parameters of a function declaration

stmts ::= 
	| stmt stmts                 --- statements are a list of statement
	| epsilon                    --- stop the looping


function ::= 
	| fun type identifier params { stmts }     --- declaration of a function, returns the last computed value 

type ::=  
	| int                         --- variable can be of three types at the moment int, boolean, fun
	| boolean 
	| fun