Make XPath-like `//a/b` recursive structure traversal easier in jq,
which then becomes:
..|.a?.b?
The `?` operator suppresses errors about . not being an array or object.
The `..` operator is equivalent to calling the new `recurse_down`
built-in, which in turn is equivalent to
recurse(.[]?)
Note that `..a` is not supported; neither is `...a`. That could be add
added, but it doesn't seem worth the trouble of saving the need to type
a '|'.
This prevents the circuluar dependency between parser.gen.h and
lexer.gen.h. Newer versions of bison add a prototype for yyparse() to
parser.gen.h that include the as-yet-undeclared yyscan_t type.
IDENT syntax now includes ASCII letters and underscores, so
'.foo_bar' now works. Non-ASCII letters won't work in IDENT
tokens (it's impossible to tell which non-ascii characters are
"letters" without full unicode tables), so '.données' is still
a syntax error (the workaround is '.["données"]', since you can
put anything you like in a string).
Nicolas Williams