diff options
Diffstat (limited to 'lib/trivial.nix')
| -rw-r--r-- | lib/trivial.nix | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/trivial.nix b/lib/trivial.nix index 25ce35570fdf..c517a758fd6c 100644 --- a/lib/trivial.nix +++ b/lib/trivial.nix @@ -53,6 +53,31 @@ rec { # argument, but it's nice this way if several uses of `extends` are cascaded. extends = f: rattrs: self: let super = rattrs self; in super // f self super; + # Create an overridable, recursive attribute set. For example: + # + # nix-repl> obj = makeExtensible (self: { }) + # + # nix-repl> obj + # { __unfix__ = «lambda»; extend = «lambda»; } + # + # nix-repl> obj = obj.extend (self: super: { foo = "foo"; }) + # + # nix-repl> obj + # { __unfix__ = «lambda»; extend = «lambda»; foo = "foo"; } + # + # nix-repl> obj = obj.extend (self: super: { foo = super.foo + " + "; bar = "bar"; foobar = self.foo + self.bar; }) + # + # nix-repl> obj + # { __unfix__ = «lambda»; bar = "bar"; extend = «lambda»; foo = "foo + "; foobar = "foo + bar"; } + makeExtensible = makeExtensibleWithCustomName "extend" fix'; + + # Same as `makeExtensible` but the name of the extending attribute is + # customized. + makeExtensibleWithCustomName = extenderName: extenderFun: rattrs: + extenderFun rattrs // { + ${extenderName} = f: makeExtensibleWithCustomName extenderName extenderFun (extends f rattrs); + }; + # Flip the order of the arguments of a binary function. flip = f: a: b: f b a; @@ -113,4 +138,7 @@ rec { */ warn = msg: builtins.trace "WARNING: ${msg}"; info = msg: builtins.trace "INFO: ${msg}"; + + fetchMD5warn = name: context : data : info + "Deprecated use of MD5 hash in ${name} to fetch ${context}" data; } |