documentation/docs/language/31-grammar.md

Grammar

The grammar for the language is still a work in progress and may take some time to become concrete but every now and then I update this page to add more to it or fix any incongruencies with the parser’s actual implementation. The grammar starts from the simplest building blocks and then progresses to the more complex (heavily composed) ones and these are placed into sections whereby they are related.

TODO: Finish implementing this

Literals

These make are the basic atoms that define literals.

letter    ::= "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K"
            | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V"
            | "W" | "X" | "Y" | "Z" | "a" | "b" | "c" | "d" | "e" | "f" | "g"
            | "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r"
            | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z";
number    ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";

float     ::= (number | {number}), ".", (number | {number});

Expressions

Expressions come in many forms and are defined here.

expr      ::= literal | binop | unaryop | parens | ident;

literal   ::= number | float;

ident     ::= letter | { letter, number };

parens    ::= "(", expr, ")";

infix     ::= "+" | "-" | "*" | "-";
prefix    ::= "*" | "&";
binop     ::= expr, operator, expr;
unaryop   ::= prefix, operator;

exprList  ::= [expr] | (expr, {",", expr});

funccall  ::= ident, "(", exprList, ")";

TODO: Add |, & (infix), && and || operators support first before adding them here

Statements

Statements are inevitably the building blocks of a program and make use of all the former defined sections of the grammar and more of themsleves in some cases as well.

module    ::= "module", ident, ";", {decl, ";"};
decl      ::= vdecl | funcDecl;



statement ::= discard | vdecl;







discard   ::= "discard", expr, ";";


vdecl     ::= type, identifier, [assign], ";";
type      ::= "int" | "uint" | ident | ptrType;
ptrType   ::= type, "*";
assign    ::= "=", expr;


parmList  ::= [type, ident] | {(type, ident), ","};
funcdecl  ::= type, identifier, "(", parmList, ")", "{", {statement, ";"}, "}";


if        ::= "if", "(", expr, ")", "{", { statement }, "}",
             [ { "else", if } | ( "else", "{", { statement, ";" }, "}") ];

while     ::= "while", "(", expr, ")", "{", { statement, ";" }, "}";

(* TODO: Check if the below is correct actually *)
for       ::= "for", "(", statement, ";", expr, ";", statement, ")", "{", {statement, ";"}, "}";