Function parseVarDef

src/parser/syntaxes/statements.ts:108–145

* ```abnf * VarDef = ("let" / "var") Dest [":" Type] "=" Expr * ```

(s: ITokenStream)

 * ```
*/
function parseVarDef(s: ITokenStream): Ast.Definition {
	const startPos = s.getPos();

	let mut: boolean;
	switch (s.getTokenKind()) {
		case TokenKind.LetKeyword: {
			mut = false;
			break;
		}
		case TokenKind.VarKeyword: {
			mut = true;
			break;
		}
		default: {
			throw unexpectedTokenError(s.getTokenKind(), s.getPos());
		}
	}
	s.next();

	const dest = parseDest(s);

	let type: Ast.TypeSource | undefined;
	if (s.is(TokenKind.Colon)) {
		s.next();
		type = parseType(s);
	}

	s.expect(TokenKind.Eq);
	s.next();

	if (s.is(TokenKind.NewLine)) {
		s.next();
	}

	const expr = parseExpr(s, false);

	return NODE('def', { dest, varType: type, expr, mut, attr: [] }, startPos, s.getPos());
}

/**
 * ```abnf