Parser

[TommYDeeee]

Parser for small subset of YARA language. It takes lexer tokens and converts them into proper SyntaxKind representation. Rowan library is used for underlying red-green tree representation that stores nodes and tokens. This is the first version of syntax. This syntax tree contains error nodes and also whitespace characters that belongs to specific node.

The example of supported rule for given subset is:

//Global comment

//Rule comment
rule test
{
	//Rule block comment

	//String comment
	strings:
		$a = "foo"
		$b = "bar"
	condition:
		$a or
		$b and true
}

Basic operator precedence and parsing is implemented using pratt parsing. So far only AND, OR and NOT operators are supported and variables, plain strings and true/false boolean constants.

Error recovery is present and done by using first set for LL grammar, this might need some tweaks in future