jhh@sprite.Berkeley.EDU (John H. Hartman) (11/24/90)
I'd like to write a Perl program that evaluates expressions with the following grammar: expr -> expr op expr expr -> ( expr ) expr -> 1 expr -> 0 op -> || op -> && Does anyone have a program that does something similar? John ----------------------------------------------------------------------- John H. Hartman Graduate Student, UCB Sprite project jhh@sprite.berkeley.edu
lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) (11/25/90)
In article <9171@pasteur.Berkeley.EDU> jhh@sprite.Berkeley.EDU (John H. Hartman) writes:
:
: I'd like to write a Perl program that evaluates expressions with the
: following grammar:
:
: expr -> expr op expr
: expr -> ( expr )
: expr -> 1
: expr -> 0
: op -> ||
: op -> &&
:
:
: Does anyone have a program that does something similar?
My brother-in-law Mark Biggar (who did the big* packages) is about to
release a parser generator that takes an ll(1) grammar and turns it
into a recursive descent tokener/parser. The above grammar isn't ll(1)
but could be turned into one.
Larry