Maude-help mailing list

[Todd Wilson <twilson AT csufresno.edu>]

Is there a way that I can get Maude to (meta)parse literal constants 
without also automatically parsing expressions involving these?

For example, I would like to define a module EXP for representing 
expressions from a programming language, which are meant to include 
literal integer and string constants, but *no* operations on them, so 
that, after

    fmod TEST is
        protecting EXP .
        op f : Exp -> Exp .
    endfm

the calls

    metaParse(upModule('TEST, true), 'f '( '123 '), 'Exp)
    metaParse(upModule('TEST, true), 'f '( '"abc" '), 'Exp)

would produce, respectively,

    ResultPair: {'f['s_^123['0.Zero]],'Exp}
    ResultPair: {'f['"1234".String],'Exp}

but that, for example,

    metaParse(upModule('TEST, true), 'f '( '123 '+ '1 '), 'Exp)

would fail, as addition is not defined in EXP.  It seems that if I 
import NAT or STRING into EXP, I'm forced to accept all of the 
operations defined there.

Todd Wilson
Department of Computer Science
California State University, Fresno