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<message 
  url="2009/01/d1e905442fb5ce55cfc4baef864b75cc"
  from="David Allsopp &lt;dra-news@m...&gt;"
  author="David Allsopp"
  date="2009-01-29T10:41:14"
  subject="RE: [Caml-list] Defining a family of functors"
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<thread subject="Defining a family of functors">
<msg 
  url="2009/01/f7ca13d9cc4ee13a6a08d9db855b9cb7"
  from="Michaël_Grünewald &lt;michaelgrunewald@y...&gt;"
  author="Michaël_Grünewald"
  date="2009-01-26T15:08:38"
  subject="Defining a family of functors">
<msg 
  url="2009/01/3ac0c3210d8125d897f761fbf92e4bd8"
  from="Jacques Carette &lt;carette@m...&gt;"
  author="Jacques Carette"
  date="2009-01-26T15:16:34"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/d2c63b2f7626796ec90499b50f2cf5a5"
  from="Andrej Bauer &lt;andrej.bauer@a...&gt;"
  author="Andrej Bauer"
  date="2009-01-27T14:30:29"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/e0c885a82a80905f27ea953e549edbf7"
  from="Jacques Carette &lt;carette@m...&gt;"
  author="Jacques Carette"
  date="2009-01-27T14:48:20"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/8d8e54f793872ffd56af17cf4847374b"
  from="David Teller &lt;David.Teller@m...&gt;"
  author="David Teller"
  date="2009-01-27T21:12:52"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/1753e428b7e5e27bce761f4376dcfc36"
  from="Nicolas Pouillard &lt;nicolas.pouillard@g...&gt;"
  author="Nicolas Pouillard"
  date="2009-01-28T00:33:36"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/521ae12c093f87e36498da99ae549e1b"
  from="David Teller &lt;David.Teller@m...&gt;"
  author="David Teller"
  date="2009-01-28T21:18:29"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
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  date="2009-01-29T09:38:48"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/d1e905442fb5ce55cfc4baef864b75cc"
  from="David Allsopp &lt;dra-news@m...&gt;"
  author="David Allsopp"
  date="2009-01-29T10:41:14"
  subject="RE: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/084cca644aebe0a7eee115861cf4acae"
  from="Mauricio Fernandez &lt;mfp@a...&gt;"
  author="Mauricio Fernandez"
  date="2009-01-29T21:15:00"
  subject="Re: [Caml-list] Defining a family of functors">
<msg 
  url="2009/01/05f780a2c38623a81af65fd384bb7637"
  from="Michaël_Grünewald &lt;michaelgrunewald@y...&gt;"
  author="Michaël_Grünewald"
  date="2009-01-30T08:25:30"
  subject="Re: [Caml-list] Defining a family of functors">
</msg>
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</msg>
</thread>

<contents>
&gt; &gt; On the other hand, it was pointed to me that Alain already wrote a
&gt; &gt; compiler patch implementing first-class modules.
&gt; 
&gt; That's right.

I have two questions - the first of which will probably demonstrate my lack of skill with the OCaml module system.

1. Does first-class modules, as with first-class functions mean that you can pass them around in code? For example, I have a web-app where all of the stuff which has to access databases is put into a single module with a known signature DB. I then have two modules MSSQLDriver and PGSQLDriver which implement the database functions for two different back-ends and have in DB.ml

module DB = MSSQLDriver
include DB

So when I build for Postgres, I just change the module statement and recompile. Would first class modules allow me to read the back-end configuration from a config file and write something like:

module DB = if Config.driver = `MSSQL then MSSQLDriver else PGSQLDriver

Or is it about something totally different? :o)

2. Is this patch intended for a future version of OCaml or just for research purposes?


David

</contents>

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