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Move property processing, type checking, and merge code into a function

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This makes the relationship between property types clearer, and more
importantly will let option types parameterized by other option types
reuse the code for delegated type checking and merging.
This commit is contained in:
Shea Levy 2014-05-01 17:29:30 -04:00 committed by Nicolas B. Pierron
parent decf15fd57
commit 9255c48a06
1 changed files with 36 additions and 22 deletions
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58
lib/modules.nix
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@ -106,12 +106,9 @@ rec {
else []
) configs);
nrOptions = count (m: isOption m.options) decls;
# Process mkMerge and mkIf properties.
defns' = concatMap (m:
if m.config ? ${name}
then map (m': { inherit (m) file; value = m'; }) (dischargeProperties m.config.${name})
else []
) configs;
# Extract the definitions for this loc
defns' = map (m: { inherit (m) file; value = m.config.${name}; })
(filter (m: m.config ? ${name}) configs);
in
if nrOptions == length decls then
let opt = fixupOptionType loc (mergeOptionDecls loc decls);
@ -177,27 +174,17 @@ rec {
config value. */
evalOptionValue = loc: opt: defs:
let
# Process mkOverride properties, adding in the default
# value specified in the option declaration (if any).
defsFinal' = filterOverrides
((if opt ? default then [{ file = head opt.declarations; value = mkOptionDefault opt.default; }] else []) ++ defs);
# Sort mkOrder properties.
defsFinal =
# Avoid sorting if we don't have to.
if any (def: def.value._type or "" == "order") defsFinal'
then sortProperties defsFinal'
else defsFinal';
# Add in the default value for this option, if any.
defs' = (optional (opt ? default)
{ file = head opt.declarations; value = mkOptionDefault opt.default; }) ++ defs;
# Handle properties, check types, and merge everything together
inherit (mergeDefinitions loc opt.type defs') defsFinal mergedValue;
files = map (def: def.file) defsFinal;
# Type-check the remaining definitions, and merge them if
# possible.
merged =
if defsFinal == [] then
throw "The option `${showOption loc}' is used but not defined."
else
fold (def: res:
if opt.type.check def.value then res
else throw "The option value `${showOption loc}' in `${def.file}' is not a ${opt.type.name}.")
(opt.type.merge loc defsFinal) defsFinal;
mergedValue;
# Finally, apply the ‘apply’ function to the merged
# value. This allows options to yield a value computed
# from the definitions.
@ -209,6 +196,33 @@ rec {
inherit files;
};
# Merge definitions of a value of a given type
mergeDefinitions = loc: type: defs: rec {
defsFinal =
let
# Process mkMerge and mkIf properties
discharged = concatMap (m:
map (value: { inherit (m) file; inherit value; }) (dischargeProperties m.value)
) defs;
# Process mkOverride properties
overridden = filterOverrides discharged;
# Sort mkOrder properties
sorted =
# Avoid sorting if we don't have to.
if any (def: def.value._type or "" == "order") overridden
then sortProperties overridden
else overridden;
in sorted;
# Type-check the remaining definitions, and merge them
mergedValue = fold (def: res:
if type.check def.value then res
else throw "The option value `${showOption loc}' in `${def.file}' is not a ${type.name}.")
(type.merge loc defsFinal) defsFinal;
};
/* Given a config set, expand mkMerge properties, and push down the
other properties into the children. The result is a list of
config sets that do not have properties at top-level. For