Basix is a parser generator that can generate C# and JavaScript recursive descent parsers from a simplistic grammar definition language with an easily extensible code generation layer.
You can generate a parser instantly by moving into the project folder and running dotnet run <GRAMMARFILE> [-o <OUTPUTFILE>]
The definition syntax of Basix is very simple and subject to change in the future.
A simple use of the grammar syntax could be parsing a math equation.
Literal > .NUM | .ID | .STR;
=Div;
DivQ > / Literal;
Div > Literal DivQ | Literal;
=Mul;
MulQ > * Mul;
Mul > Div MulQ | Div;
=Sub;
SubQ > - Sub;
Sub > Mul SubQ | Mul;
=Add;
AddQ > + Add;
Add > Sub AddQ | Sub;
Note the use of = in this grammar, basix grammars are currently parsed from top to bottom with a single pass, meaning if you want to use a rule defined later in the file you need to tell the program it is going to be defined later
This grammar uses two rules for each operator, necessary to parse the equation correctly as it eliminates left-recursion wikipedia while correctly parsing left-associative operators (addition is left-associative because you do 1 + 2 before 3 in 1 + 2 + 3).
There are some cases where you need to match 0 or more of the same rule, in which case you can use the * symbol (when matching * or ? as part of the grammar, use .MUL and .QMARK instead of */?, or A * B could be parsed as A* B).
List > [ Element* ];