I don't think this is really what Norman wants. Instead, I think he's looking for a definition of `form` as it appears in various error messages that mention "form".
Sam On Fri, May 16, 2014 at 1:52 PM, Ryan Culpepper <[email protected]> wrote: > If you refer to the "Syntax Model" section of the reference > (http://docs.racket-lang.org/reference/syntax-model.html), you'll see that > Racket syntax is defined by two passes, called "read" and "expand". > > The grammar you gave in your message is what I would call a "term"---it's > anything that the read pass can turn into a syntax object. In other words, > terms are what syntax objects represent. > > The word "form" generally means any of the non-terminals of the Racket > language that the macro expander cares about, such as "expression forms" and > "definition forms". There are also "module-level forms", which include > require and provide. There's a list of these nonterminals in the subsection > "Fully Expanded Programs" > (http://docs.racket-lang.org/reference/syntax-model.html#%28part._fully-expanded%29). > You can think of the syntax of Racket roughly as that grammar with "or a > macro that eventually expands into one of the above" added to every > production there---except the one for "formals". The "formals" non-terminal > doesn't correspond to an expansion context, nor do "module-path" or > "raw-require-spec"; thus, they are not considered forms. Neither is > something like "cond-clause", for example; it's just an auxiliary > non-terminal for the "cond" macro. > > To complicate matters, macros can also create new expansion contexts and > thus new kinds of forms. For example, the class macro introduces "class-body > forms", which include expressions and definitions as well as other syntaxes > that are only significant immediately within class bodies, such as "init" > and "abstract" forms. > > Ryan > > > > On 05/16/2014 12:28 PM, Norman Ramsey wrote: >> >> Where would I find out, preferably in the Racket documentation, >> the definition of what a 'form' is? I'm thinking along these lines: >> >> A form is one of: >> - a symbol >> - a numeric literal >> - a string literal >> - ... possibly other literals? ... >> - a sequence of forms wrapped in one pair of parentheses >> >> Is this the right idea? Or is the word 'form' reserved only for >> things wrapped in parentheses? >> >> >> Norman >> >> >> P.S. In the Racket documentation, I found the section on 'Syntactic >> Forms', but I haven't found a definition of what a form is, and I >> haven't found the word 'form' in the index. >> >> >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users >> > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
