nixpkgs/pkgs/lib/modules.nix
Nicolas Pierron 1557cfd0c6 split moduleClosure in two parts:
* unifyModuleSyntax: handle all kind of module syntax to convert them into
  a module which has the following form:

  {
    imports = [ <paths> ];
    options = <attribute set of options declarations>;
    config = <attribute set (with properties) of option definitions>;
  }

  This function assume that there is at most one imported attribute set which
  correspond to option declarations.

* moduleClosure: handle a list of module's paths which are converted with
  the previous function to do the closure of the imports with the function
  lazyGenericClosure (which does the same as builtins.genericClosure except
  that it doesn't evaluate the content of modules).  The "key" and "paths"
  attributes are left to be used as debug information in futur
  implementation(s).

svn path=/nixpkgs/trunk/; revision=17108
2009-09-14 13:19:00 +00:00

91 lines
2.2 KiB
Nix

# NixOS module handling.
let lib = import ./default.nix; in
with { inherit (builtins) head tail; };
with import ./trivial.nix;
with import ./lists.nix;
with import ./misc.nix;
with import ./attrsets.nix;
with import ./properties.nix;
rec {
# Unfortunately this can also be a string.
isPath = x: !(
builtins.isFunction x
|| builtins.isAttrs x
|| builtins.isInt x
|| builtins.isBool x
|| builtins.isList x
);
importIfPath = path:
if isPath path then
import path
else
path;
applyIfFunction = f: arg:
if builtins.isFunction f then
f arg
else
f;
# Convert module to a set which has imports / options and config
# attributes.
unifyModuleSyntax = m:
let
getImports = m:
if m ? config || m ? options then
attrByPath ["imports"] [] m
else
toList (rmProperties (attrByPath ["require"] [] (delayProperties m)));
getImportedPaths = m: filter isPath (getImports m);
getImportedSets = m: filter (x: !isPath x) (getImports m);
getConfig = m:
removeAttrs (delayProperties m) ["require"];
in
if m ? config || m ? options then
m
else
{
imports = getImportedPaths m;
config = getConfig m;
} // (
if getImportedSets m != [] then
assert tail (getImportedSets m) == [];
{ options = head (getImportedSets m); }
else
{}
);
moduleClosure = initModules: args:
let
moduleImport = m: lib.addErrorContext "Import module ${m}." (
(unifyModuleSyntax (applyIfFunction (import m) args)) // {
# used by generic closure to avoid duplicated imports.
key = m;
paths = [ m ];
}
);
getImports = m: attrByPath ["imports"] [] m;
in
lazyGenericClosure {
startSet = map moduleImport initModules;
operator = m: map moduleImport (getImports m);
};
selectDeclsAndDefs = modules:
lib.concatMap (m:
if m ? config || m ? options then
[ (attrByPath ["options"] {} m) ]
++ [ (attrByPath ["config"] {} m) ]
else
[ m ]
) modules;
}