A Minimal (Monadic) Parser Combinators (MiPaCo) project in C#.
It is very closely modelled on Monadic Parsing in Haskell
by Hutton and Meijer.
In the context of this project minimal means hewing as close as possible to the Hutton & Meijer
paper, and making no concessions to efficiency.
For example, the parser for a string is modelled on the Haskell
string (c:cs) = do {char c; string cs; return (c:cs)} and is likewise recursive, even though
an iterative version would certainly have been more efficient.
A result of this is that the entire library (which is contained in MiPaCo/Combinators.cs) is
just a few dozen lines of code (and most of those lines are helpers; the core lines are
probably less than a dozen in number).
Thus one way to use the library is to simply copy the relevant lines into whatever
project needs them.
The solution contains two examples of using the library: CalculatorExample (drawn directly
from the Hutton & Meijer paper) and SqlExample which parses a small subset of SQL 'where'
clauses into an Abstract Syntax Tree.
The current design models the output of a parser as an IEnumerable making it very similar
to the Haskell lists used by Hutton & Meijer.
Other alternatives include an 'Option' class (assuming no more than one parse is generated)
or returning the result of a parse and representing failure by an exception.
The monadic nature of the parsers allows us to implement LINQ extension methods which in turn
allow LINQ query syntax to write parsers.
Alas, LINQ query syntax does not include a union keyword which means that choice (i.e.,
the Or combinator) requires stepping outside of the query syntax.
See Sprache for another monadic parser combinator library in C#. It is probably much more efficient than MiPaCo and better suited for serious work.