H5LT lexer and parser share state with global variables when there is no need.

[gnuoyd]

The lexer uses an unconventional strategy for parsing lexical categories NUMBER (decimal numbers) and STRING (double-quoted strings) that involves sharing the parse context with the lexer using global variables. There are a couple of problems with that. First, the lexer is too complicated for the simple tokenization it performs—it's hard to tell if it is correct. Second, as @seanm points out, the shared global variables spill into the namespace shared by other libraries and application programs—e.g., VTK.