74 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
			
		
		
	
	
			74 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
| <section xmlns="http://docbook.org/ns/docbook"
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|          xmlns:xlink="http://www.w3.org/1999/xlink"
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|          xml:id="sec-language-ocaml">
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|  <title>OCaml</title>
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| 
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|  <para>
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|   OCaml libraries should be installed in <literal>$(out)/lib/ocaml/${ocaml.version}/site-lib/</literal>. Such directories are automatically added to the <literal>$OCAMLPATH</literal> environment variable when building another package that depends on them or when opening a <literal>nix-shell</literal>.
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|  </para>
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| 
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|  <para>
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|   Given that most of the OCaml ecosystem is now built with dune, nixpkgs includes a convenience build support function called <literal>buildDunePackage</literal> that will build an OCaml package using dune, OCaml and findlib and any additional dependencies provided as <literal>buildInputs</literal> or <literal>propagatedBuildInputs</literal>.
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|  </para>
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| 
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|  <para>
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|   Here is a simple package example. It defines an (optional) attribute <literal>minimumOCamlVersion</literal> that will be used to throw a descriptive evaluation error if building with an older OCaml is attempted. It uses the <literal>fetchFromGitHub</literal> fetcher to get its source. It sets the <literal>doCheck</literal> (optional) attribute to <literal>true</literal> which means that tests will be run with <literal>dune runtest -p angstrom</literal> after the build (<literal>dune build -p angstrom</literal>) is complete. It uses <literal>alcotest</literal> as a build input (because it is needed to run the tests) and <literal>bigstringaf</literal> and <literal>result</literal> as propagated build inputs (thus they will also be available to libraries depending on this library). The library will be installed using the <literal>angstrom.install</literal> file that dune generates.
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|  </para>
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| 
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| <programlisting>
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| { stdenv, fetchFromGitHub, buildDunePackage, alcotest, result, bigstringaf }:
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| 
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| buildDunePackage rec {
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|   pname = "angstrom";
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|   version = "0.10.0";
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| 
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|   minimumOCamlVersion = "4.03";
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| 
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|   src = fetchFromGitHub {
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|     owner  = "inhabitedtype";
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|     repo   = pname;
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|     rev    = version;
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|     sha256 = "0lh6024yf9ds0nh9i93r9m6p5psi8nvrqxl5x7jwl13zb0r9xfpw";
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|   };
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| 
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|   buildInputs = [ alcotest ];
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|   propagatedBuildInputs = [ bigstringaf result ];
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|   doCheck = true;
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| 
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|   meta = {
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|     homepage = https://github.com/inhabitedtype/angstrom;
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|     description = "OCaml parser combinators built for speed and memory efficiency";
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|     license = stdenv.lib.licenses.bsd3;
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|     maintainers = with stdenv.lib.maintainers; [ sternenseemann ];
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|   };
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| }
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| </programlisting>
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| 
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|  <para>
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|   Here is a second example, this time using a source archive generated with <literal>dune-release</literal>. It is a good idea to use this archive when it is available as it will usually contain substituted variables such as a <literal>%%VERSION%%</literal> field. This library does not depend on any other OCaml library and no tests are run after building it.
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|  </para>
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| 
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| <programlisting>
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| { stdenv, fetchurl, buildDunePackage }:
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| 
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| buildDunePackage rec {
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|   pname = "wtf8";
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|   version = "1.0.1";
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| 
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|   minimumOCamlVersion = "4.01";
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| 
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|   src = fetchurl {
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|     url = "https://github.com/flowtype/ocaml-${pname}/releases/download/v${version}/${pname}-${version}.tbz";
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|     sha256 = "1msg3vycd3k8qqj61sc23qks541cxpb97vrnrvrhjnqxsqnh6ygq";
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|   };
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| 
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|   meta = with stdenv.lib; {
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|     homepage = https://github.com/flowtype/ocaml-wtf8;
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|     description = "WTF-8 is a superset of UTF-8 that allows unpaired surrogates.";
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|     license = licenses.mit;
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|     maintainers = [ maintainers.eqyiel ];
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|   };
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| }
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| </programlisting>
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| </section>
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