infra - nix configuration for my machines

	Commit message (Expand)	Author	Files	Lines
2020-01-11	lexer: delete redundant test.	franck cuny	1	-32/+1
2020-01-11	lexer: support more operator tokens.	franck cuny	2	-1/+31
2020-01-11	lexer: initial lexer	franck cuny	2	-0/+218