diff options
author | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2013-10-28 19:48:30 +0100 |
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committer | Eelco Dolstra <eelco.dolstra@logicblox.com> | 2013-10-28 22:45:57 +0100 |
commit | 73f32d03758a53ad1baac31795cfd99e325032f3 (patch) | |
tree | 8df21c7319e758a85a4916890714b0d90c631a67 /lib/types.nix | |
parent | dbefab9cf42c09444dd2554380104096969c0728 (diff) |
Show precise error messages in option merge failures
For instance, if time.timeZone is defined multiple times, you now get the error message: error: user-thrown exception: The unique option `time.timeZone' is defined multiple times, in `/etc/nixos/configurations/misc/eelco/x11vnc.nix' and `/etc/nixos/configuration.nix'. while previously you got: error: user-thrown exception: Multiple definitions of string. Only one is allowed for this option. and only an inspection of the stack trace gave a clue as to what option caused the problem.
Diffstat (limited to 'lib/types.nix')
-rw-r--r-- | lib/types.nix | 76 |
1 files changed, 37 insertions, 39 deletions
diff --git a/lib/types.nix b/lib/types.nix index 3c21e34879cf5..34d06a9144fed 100644 --- a/lib/types.nix +++ b/lib/types.nix @@ -19,27 +19,24 @@ rec { }; - # name (name of the type) - # check (check the config value) - # merge (default merge function) - # getSubOptions (returns sub-options for manual generation) isOptionType = isType "option-type"; mkOptionType = - { name - , check ? (x: true) - , merge ? mergeDefaultOption - , merge' ? args: merge - , getSubOptions ? prefix: {} + { # Human-readable representation of the type. + name + , # Function applied to each definition that should return true if + # its type-correct, false otherwise. + check ? (x: true) + , # Merge a list of definitions together into a single value. + merge ? mergeDefaultOption + , # Return a flat list of sub-options. Used to generate + # documentation. + getSubOptions ? prefix: {} }: - { _type = "option-type"; - inherit name check merge merge' getSubOptions; + inherit name check merge getSubOptions; }; - addToPrefix = args: name: args // { prefix = args.prefix ++ [name]; }; - - types = rec { unspecified = mkOptionType { @@ -49,7 +46,7 @@ rec { bool = mkOptionType { name = "boolean"; check = builtins.isBool; - merge = fold lib.or false; + merge = args: fold lib.or false; }; int = mkOptionType { @@ -60,7 +57,7 @@ rec { string = mkOptionType { name = "string"; check = builtins.isString; - merge = lib.concatStrings; + merge = args: lib.concatStrings; }; # Like ‘string’, but add newlines between every value. Useful for @@ -68,54 +65,56 @@ rec { lines = mkOptionType { name = "string"; check = builtins.isString; - merge = lib.concatStringsSep "\n"; + merge = args: lib.concatStringsSep "\n"; }; commas = mkOptionType { name = "string"; check = builtins.isString; - merge = lib.concatStringsSep ","; + merge = args: lib.concatStringsSep ","; }; envVar = mkOptionType { name = "environment variable"; inherit (string) check; - merge = lib.concatStringsSep ":"; + merge = args: lib.concatStringsSep ":"; }; attrs = mkOptionType { name = "attribute set"; check = isAttrs; - merge = fold lib.mergeAttrs {}; + merge = args: fold lib.mergeAttrs {}; }; # derivation is a reserved keyword. package = mkOptionType { name = "derivation"; check = isDerivation; + merge = mergeOneOption; }; path = mkOptionType { name = "path"; # Hacky: there is no ‘isPath’ primop. check = x: builtins.unsafeDiscardStringContext (builtins.substring 0 1 (toString x)) == "/"; + merge = mergeOneOption; }; # drop this in the future: - list = builtins.trace "types.list is deprecated; use types.listOf instead" types.listOf; + list = builtins.trace "`types.list' is deprecated; use `types.listOf' instead" types.listOf; listOf = elemType: mkOptionType { name = "list of ${elemType.name}s"; check = value: isList value && all elemType.check value; - merge' = args: defs: imap (n: def: elemType.merge' (addToPrefix args (toString n)) [def]) (concatLists defs); + merge = args: defs: imap (n: def: elemType.merge (addToPrefix args (toString n)) [def]) (concatLists defs); getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["*"]); }; attrsOf = elemType: mkOptionType { name = "attribute set of ${elemType.name}s"; check = x: isAttrs x && all elemType.check (lib.attrValues x); - merge' = args: lib.zipAttrsWith (name: - elemType.merge' (addToPrefix (args // { inherit name; }) name)); + merge = args: lib.zipAttrsWith (name: + elemType.merge (addToPrefix (args // { inherit name; }) name)); getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name>"]); }; @@ -138,43 +137,39 @@ rec { if isList x then listOnly.check x else if isAttrs x then attrOnly.check x else false; - merge' = args: defs: attrOnly.merge' args (imap convertIfList defs); + merge = args: defs: attrOnly.merge args (imap convertIfList defs); getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name?>"]); }; uniq = elemType: mkOptionType { inherit (elemType) name check; - merge = list: - if length list == 1 then - head list - else - throw "Multiple definitions of ${elemType.name}. Only one is allowed for this option."; + merge = mergeOneOption; getSubOptions = elemType.getSubOptions; }; none = elemType: mkOptionType { inherit (elemType) name check; - merge = list: - throw "No definitions are allowed for this option."; + merge = args: list: + throw "No definitions are allowed for the option `${showOption args.prefix}'."; getSubOptions = elemType.getSubOptions; }; nullOr = elemType: mkOptionType { name = "null or ${elemType.name}"; check = x: builtins.isNull x || elemType.check x; - merge' = args: defs: + merge = args: defs: if all isNull defs then null else if any isNull defs then - throw "Some but not all values are null." - else elemType.merge' args defs; + throw "The option `${showOption args.prefix}' is defined both null and not null, in ${showFiles args.files}." + else elemType.merge args defs; getSubOptions = elemType.getSubOptions; }; functionTo = elemType: mkOptionType { name = "function that evaluates to a(n) ${elemType.name}"; check = builtins.isFunction; - merge' = args: fns: - fnArgs: elemType.merge' args (map (fn: fn fnArgs) fns); + merge = args: fns: + fnArgs: elemType.merge args (map (fn: fn fnArgs) fns); getSubOptions = elemType.getSubOptions; }; @@ -183,8 +178,7 @@ rec { mkOptionType rec { name = "submodule"; check = x: isAttrs x || builtins.isFunction x; - merge = merge' {}; - merge' = args: defs: + merge = args: defs: let coerce = def: if builtins.isFunction def then def else { config = def; }; modules = opts' ++ map coerce defs; @@ -204,4 +198,8 @@ rec { }; + + /* Helper function. */ + addToPrefix = args: name: args // { prefix = args.prefix ++ [name]; }; + } |