On 2018-03-15, at 11:02:17, Charles Mills wrote:
> Your points are good but FWIW ; is a command separator and at a "higher
> level" than quoted string parsing.
> Find "foo;bar" is for better or worse exactly the same as
> Find "foobar"
>
I believe not. Find "foo;bar" is the same as
Find "foo
bar"
... both of which are reported as syntax errors.
Very bad design. A "higher level" executive has no business performing
a bottom-up parse of commands it passes to a lower level processor. At
least it should support an escape convention, such as:
Find "foo\;bar"
... with the "\" protecting the ";". The command passed to the lower level
would then simply be:
Find "foo;bar"
But that couldn't be done with a simple TRT. Oh, my gosh! Think of the
performance implications of doing it right!
Feedback from a parser to its lexical analyzer is generally deemed
harmful (but consider PL/I!) OTOH, the lexical analyzer should not
impose limitations on the parser's syntax.
> printf( "foo;bar\n" ); /* in C */
>
C's lexical analyzer knows enough to recognize that the second ";", but
not the first, is a token separator.
-- gil
