On Sun, 2010-11-28 at 15:57 -0500, Roman Ivanov wrote: [ . . . ] > AFAIK, LINQ is _not_ SQL embedded into C# or VB. It's a mechanism that > allows C# to examine expressions (written in C#, as strange as they > might look) and translate them to SQL (or whatever).
I have no idea how LINQ is realized but I know what happens in Groovy (and Python). > LINQ can take two forms. > > First: > var query = from s in names > where s.Length == 5 > orderby s > select s.ToUpper(); > > Second: > var query = names.where(s => s.Length == 5) > .orderby(s => s) > .select(s => s.ToUpper()); > > They are semantically identical, but I like the second syntax much more, > because it uses existing language features, works with auto-completion > and is much more readable in complex cases. Actually I prefer the former exactly because it is not an attempt to do a DSL by suffering the constraints of the language parser. > To support something like that a language needs to have tools for > introspection of its own code. Yes, and this is why Groovy, Python, etc. are good at this sort of stuff and C, C++, Fortran, D, Go, etc., are generally less good at it. Basically this is one of the benefits of a full meta-object protocol. Something you really don't want in performance code. > > 2-Having such an compiler plugin architecture, will enable you f.i to > > seamless use Go, Lisp whatever within D. > > > > 3-Even if these plugins (please note > more than one) are just for SQL, > > you got database access for free. > > LINQ for databases is a bit overrated. Writing real SQL queries is often > simpler. LINQ query generator does some optimizations, but it also > screws up in some cases. LINQ to objects is a different story, because > it allows for much nicer declarative syntax to do mapping and projections. The experience in the Groovy/Java community is that using a DSL in Groovy rather than faffing around with strings and SQL directly, makes this a lot faster of production, with fewer bugs. This is anecdotal evidence only though so it may just be a perception thing rather than a real effect. > > 4- I am using such an EBNF driven tool (almost written by me) to > > translate SQL scripts. // Create a new db from firebird to mssql.. > > including stored procedures, triggers etc. > > > > So sorry Denis, I know what I am talking about. > > Bjoern > -- Russel. ============================================================================= Dr Russel Winder t: +44 20 7585 2200 voip: sip:russel.win...@ekiga.net 41 Buckmaster Road m: +44 7770 465 077 xmpp: rus...@russel.org.uk London SW11 1EN, UK w: www.russel.org.uk skype: russel_winder
signature.asc
Description: This is a digitally signed message part
