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lemon-example

	An example of using a tokenizer and a grammar to validate date
	expressions; for example, "Jan 30 through Feb 15 at 8pm".

	The tokenizer is plain-old C and a lemon grammar [0] is used to
	generate the parser. 

	Lemon is written by the same author  as SQLite. It's benefis include
	a simpler grammar than yacc, thread-safety, and a looser coupling
	with the tokenizer.
    
	This repository was started from David Wheeler's C port [1] of a 
	C++ lemon tutorial [2].   The core of the tokenizer was copied 
	pretty much verbatim from Troy Hanson's lemon example [3].

	[0] http://www.hwaci.com/sw/lemon/
	[1] https://github.com/bskari/lemon-parser-tutorial
	[2] https://github.com/bskari
	[3] https://github.com/troydhanson/misc/tree/master/text_handling/lemon


Status

	Functional.  See the files test_tokenizer.sh and test_isadate.sh
	(in the regress directory) for examples of strings that are handled.

Build

	make

		Builds an object file that provides the method

				int isadate(const char *, struct emsg *);

		which returns 0 if the string is a date, and 1 otherwise.

		If the string is not recognized as a date, the emsg struct is 
		populated with an error message and a column index.


Test

	make test



Other Lemon references:

	http://linuxgazette.net/106/chirico.html

	http://brskari.wordpress.com/2012/04/29/writing-a-basic-shell-using-flex-and-lemon-part-1/