indjev99 / Minlang

A small strongly typed imperative programming language.

Minlang

A small strongly typed imperative programming language.

Semantics:

• All simple types are represented as 64 bit values.
• Function arguments are passed by value and are computed from left to right.
• Non-primitive types cannot currently be passed (by value), so we pass them by pointer manually.

Lexing:

• Start single line comments with #
• Start nested multi line comments with #> and end them with <#

Grammar:

PROGRAM ::=
    (VAR_DEF | FUN_DEF)*

VAR_DEF ::=
    var VAL_TYPE NAME ( = EXPR ) ;

FUN_DEF ::=
    fun FUN_TYPE NAME "(" ( NAME ( , NAME )* ) ")" = BODY end

BODY ::=
    (VAR_DEF | STMT)*

STMT ::=
    EXPR;
  | ADDR_EXPR = EXPR;
  | return EXPR;
  | if EXPR then BODY ( elif EXPR then BODY )* ( else BODY ) end
  | while EXPR do BODY end

EXPR ::=
    ADDR_EXPR
  | NUMBER
  | EXPR "(" ( EXPR ( , EXPR )* ) ")"
  | EXPR BIN_OP EXPR
  | UN_OP EXPR
  | & ADDR_EXPR
  | "(" EXPR ")"

ADDR_EXPR ::=
    NAME
  | EXPR [ EXPR ]
  | * EXPR
  | "(" ADDR_EXPR ")"

TYPE ::=
    int
  | wildcardPtr
  | TYPE*
  | TYPE [ NUMBER ]
  | "(" ( TYPE ( , TYPE )* ) ")"
  | TYPE "(" ( TYPE ( , TYPE )* ) ")"

Subscripting and the oparators have the usual precedences.

Primive variables and functions:

• int() nullptr()
• wildcardPtr(int) alloc(n)
• int(wildcardPtr) free(ptr)
• int() read()
• int(int) print(x)
• int() flush()
• int(int) exit(code)

Future plans:

• Imports
• Custom struct types
• Named arguments
• Other 64 bit primitive types
• Non 64 bit primitive types (requires handling alignment)