lib/options: Introduce showDefs

For pretty-printing definitions, including file and values
This commit is contained in:
Silvan Mosberger 2020-09-16 20:05:07 +02:00
parent 2ff7c3e2e1
commit 7c20e68f6b
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@ -213,6 +213,24 @@ rec {
else escaped;
in (concatStringsSep ".") (map escapeOptionPart parts);
showFiles = files: concatStringsSep " and " (map (f: "`${f}'") files);
showDefs = defs: concatMapStrings (def:
let
# Pretty print the value for display, if successful
prettyEval = builtins.tryEval (lib.generators.toPretty {} def.value);
# Split it into its lines
lines = filter (v: ! isList v) (builtins.split "\n" prettyEval.value);
# Only display the first 5 lines, and indent them for better visibility
value = concatStringsSep "\n " (take 5 lines ++ optional (length lines > 5) "...");
result =
# Don't print any value if evaluating the value strictly fails
if ! prettyEval.success then ""
# Put it on a new line if it consists of multiple
else if length lines > 1 then ":\n " + value
else ": " + value;
in "\n- In `${def.file}'${result}"
) defs;
unknownModule = "<unknown-file>";
}