The arguments are the <exp> ...<exp>. The function position is <var> or <prm>
Essentially, the grammar in sec20 extends sec8 with the ability to: - pass functions and primitives, like +, as arguments, and - compute the applied function in the function position instead of always using predefined <var>s or <prm>s Does that make sense? On Wed, Sep 10, 2014 at 2:57 PM, Daniel Bastos <dbas...@toledo.com> wrote: > I remember having had that question when I was at that chapter. I must > have thought I answered it, but I'm having it again and unable to > answer now. IOW, I'm confused. > > I'm having difficulties with this phrase too. "First, the names of > functions and primitive operations are used as arguments in > applications." > > What is an argument in application? I'm going to try to answer it. An > application is, according to the grammar of section 8, > > (<var> <exp> ...<exp>) > > or > > (<prm> <exp> ...<exp>) > > So its arguments are <var>, <exp>, ... and the final <exp>. Similarly, > the second application has arguments <prm>, <exp>, ..., <exp>. Is that > correct? > > Thank you. > > On Wed, Sep 10, 2014 at 3:25 PM, Stephen Chang <stch...@ccs.neu.edu> wrote: >> I believe it's answered in a subsequent paragraph? >> >> "The abstract functions of section 19 violate Scheme's basic grammar >> in two ways. First, the names of functions and primitive operations >> are used as arguments in applications. An argument, though, is an >> expression, and the class of expressions does not contain primitive >> operations and function names. It does contain variables, but we >> agreed that they are only those variables mentioned in variable >> definitions and as function parameters. Second, parameters are used as >> if they were functions, that is, the first position of applications. >> But the grammar of section 8 allows only the names of functions and >> primitive operations in this place." ____________________ Racket Users list: http://lists.racket-lang.org/users
