* [ligo pretty-print foo.religo] is a transpiler (for now) and needs
more work.
* Renamed functions *_ast into *_cst. One day, module AST should be
renamed CST for clarity and consistency.
* LexToken.mll for CameLIGO: Fixed printing of "Str"
into "String".
* Added CLI option --pretty to call the pretty-printer from
ParserMain.
* Use the package Terminal_size to try to determine the width
of the terminal where the source is pretty-printed.
instead of a closed set of languages. I also removed the offsets:
I simply use the current region to determine whether the
preprocessing directie starts at the beginning of a line. I also
removed scanning line indicators, to make the lexer simpler.
LexToken.mll: Moved the function [check_right_context] that
checks stylistic constraints from Lexer.mll to
LexToken.mll. While this triplicates code (as CameLIGO, PascaLIGO
and ReasonLIGO share the same constraints), the benefit is that
Lexer.mll becomes more generic and the signature for the TOKEN
module is simpler (no more exporting predicates, except for
EOF). In accordance with the change of the preprocessor, the
lexers and parsers for LIGO now depend on the kind of comments,
not a fixed set of syntaxes. This gives more versatility when
adding a new language: only the kinds of its comments are needed,
although Lexer.mll and Preproc.mll may have to be modified if
they do not already know the comment delimiters, for example line
comments starting with #.
****************************************************************
BUG: The exceptions coming from LexToken.mll when a stylistic
constraint is broken in [LexToken.check_right_context] are not
caught yet.
****************************************************************
Lexer.mll: I moved out as much as I could from the header into a
new module LexerLib. The aim is to make it easy to reuse as much
as possible of the lexer machinerie, when it cannot be used as
is.
