Dear Stephen, could you say a few words to the topic why Aldor only allows
<domain> has <category> instead of <domain or category> has <category> ? Ralf >> See AUG page 96: >> >> Has expressions >> A "has" expression has the following form: >> dom has cat >> where dom is a domain-valued expression, and cat is a category-valued >> expression. >> >> So at least "has" is different in the Axiom interpreter or in SPAD. >> > > You are right, there is a difference between Aldor and OpenAxiom. In > Aldor Type is not a category - it is a domain! > > [EMAIL PROTECTED]:~# cat mylibs.as > #include "aldor" > #include "aldorinterp" > #include "algebra" > > [EMAIL PROTECTED]:~# aldor -gloop > Aldor > > Copyright (c) 1990-2007 Aldor Software Organization Ltd (Aldor.org). > > Release: Aldor(C) version 1.1.0 for LINUX(glibc2.3) > Type "#int help" for more details. > %1 >> #include "mylibs" > Comp: 260 msec, Interp: 0 msec > %2 >> Type > () @ > with > == add () > > And subtypes of Type are categories, so like in OpenAxiom Category is > also a domain - the domain of subtypes of Type. > > %3 >> Category > () @ > with > == add () > > Domains are the members of Type and therefore also are members of one > or more Category. > > For example, in > > http://www.csd.uwo.ca/~watt/pub/reprints/2003-cahand-aldor.pdf > > Stephen Watt wrote: > > "Each value belongs to some unique type, known as its domain, and the > domains of expressions can be inferred statically. Each domain is > itself a value belonging to the domain Type. Domains may additionally > belong to some number of subtypes (of Type), known as categories." > >> %8 >> Cat:Category == with; >> >> %11 >> Integer >> () @ Join( >> PrimitiveType with >> coerce: BInt -> % >> coerce: % -> BInt >> == add () >> , >> IntegerType with export to IntegerSegment(%) >> == add () >> ) > > http://www.aldor.org/docs/HTML/chap7.html#7 > > Aldor does not use the name 'Domain' to refer to any type. So far I > have not found any explicit name for the category > > with {} > > so I guess it is a cruel little comedy that 'Domain' seems like a good > name for the top of the *category* hierachy in Aldor though it is > called 'Type' in Axiom. Meanwhile 'Domain' in Axiom corresponds to > 'Type', and 'Type' in Aldor is a domain... ;-( > >> ... > > Ralf, you are also right that 'has' has a more restricted meaning in > Aldor than in Axiom. In Axiom we can write: > > <domain> or <category> has <category> or <attribute> > > an <attribute> is just a named category with no exports. > > In the Axiom interpreter > > <category 1> has <category 2> > > is true if <category 1> is a subtype of <category 2> > > <domain> has <category> > > is true if <category> appears in the a 'Join' expression or to the > left of the keyword 'with'. This is described in ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
