diff options
| author | Naïm Favier <n@monade.li> | 2022-11-03 15:56:27 +0100 |
|---|---|---|
| committer | pennae <82953136+pennae@users.noreply.github.com> | 2022-12-08 17:52:52 +0100 |
| commit | 6a117e2759b84b9508f1d69cb5be54ca331bff98 (patch) | |
| tree | 5679f8c723a9c84da0fc40ba03bdfef6bb60e27c /lib/generators.nix | |
| parent | 0b661ce32af9baa07da56b3f48fcd3ef5611b66c (diff) | |
nixos/doc: render option values using `lib.generators.toPretty`
Render un`_type`d defaults and examples as `literalExpression`s using
`lib.generators.toPretty` so that consumers don't have to reinvent Nix
pretty-printing. `renderOptionValue` is kept internal for now intentionally.
Make `toPretty` print floats as valid Nix values (without a tilde).
Get rid of the now-obsolete `substSpecial` function.
Move towards disallowing evaluation of packages in the manual by
raising a warning on `pkgs.foo.{outPath,drvPath}`; later, this should
throw an error. Instead, module authors should use `literalExpression`
and `mkPackageOption`.
Diffstat (limited to 'lib/generators.nix')
| -rw-r--r-- | lib/generators.nix | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/lib/generators.nix b/lib/generators.nix index 06823d215e36..c0fe69389e00 100644 --- a/lib/generators.nix +++ b/lib/generators.nix @@ -278,8 +278,11 @@ rec { mapAny 0; /* Pretty print a value, akin to `builtins.trace`. - * Should probably be a builtin as well. - */ + * Should probably be a builtin as well. + * The pretty-printed string should be suitable for rendering default values + * in the NixOS manual. In particular, it should be as close to a valid Nix expression + * as possible. + */ toPretty = { /* If this option is true, attrsets like { __pretty = fn; val = …; } will use fn to convert val to a pretty printed representation. @@ -294,7 +297,10 @@ rec { introSpace = if multiline then "\n${indent} " else " "; outroSpace = if multiline then "\n${indent}" else " "; in if isInt v then toString v - else if isFloat v then "~${toString v}" + # toString loses precision on floats, so we use toJSON instead. This isn't perfect + # as the resulting string may not parse back as a float (e.g. 42, 1e-06), but for + # pretty-printing purposes this is acceptable. + else if isFloat v then builtins.toJSON v else if isString v then let lines = filter (v: ! isList v) (builtins.split "\n" v); @@ -328,7 +334,7 @@ rec { else "<function, args: {${showFnas}}>" else if isAttrs v then # apply pretty values if allowed - if attrNames v == [ "__pretty" "val" ] && allowPrettyValues + if allowPrettyValues && v ? __pretty && v ? val then v.__pretty v.val else if v == {} then "{ }" else if v ? type && v.type == "derivation" then |