This adds shift (`<<` `>>`) and bitwise logical (`&` `|` `^`) operators.
Their precedence is between the additive and ordering operations, in this order
(higher to lower):
- ... others, to additive
- `<<` and `>>`
- `&`
- `|`
- `^`
- ... others, from ordering
This is consistent with Rust, but not with C and Java, both of which make the
bitwise logical operators lower-precedence than equalities.
The previous ABNF rule names for `conjunctive-expression` and
`disjunctive-expression` have been renamed to be more consistent with the newly
added ones. Also, the rule names "abbreviate" 'conjunctive' and 'disjunctive'
with 'and' and 'or', otherwise the names were a bit too long.
Since these are a method-like syntax for unary and binary operators (as in fact
these are represented as operators in the AST), the nomenclature 'operator call'
seems appropriate, at least for now. There is no need yet to introduce notions
of associated functions (and constants).
The rules explicitly distinguish between unary and binary ones, corresponding to
unary and binary operators. This lets us exclude right away calls with too many
arguments, and gives us a way to distinguish the two kinds.
A trailing comma is allowed at the end of the one argument of binary operator
calls, if one is really inclined to use it, just for syntactic consistency with
other calls (namely, function calls).
Prohibit line terminators inside string literals. (This does not prohibit
escapes for line feed and/or carriage return; it prohibits actual line feeds and
carriage returns, which would break the string literal across lines.)
Explicate line terminators in block comments, so that an accurate line count can
be obtained more readily from the CSTs. (This is more relevant to the ACL2
formal development than to the Rust implementation, which does not have explicit
CSTs.)
Also reorder slightly some rules within the file.
