summaryrefslogtreecommitdiff
path: root/src/Conftrack.hs
diff options
context:
space:
mode:
authorstuebinm2024-06-07 17:22:08 +0200
committerstuebinm2024-06-07 17:22:08 +0200
commit17631c7294ee21a48f78ce4e51c827da93b501fa (patch)
tree4d1a25408bdc0ebac5d9251181e9ab69381c7b4c /src/Conftrack.hs
parente3cafcd9a1fc8621fdaaf33d1772bdcd8390d2bf (diff)
allow for non-required config options
Diffstat (limited to '')
-rw-r--r--src/Conftrack.hs24
1 files changed, 20 insertions, 4 deletions
diff --git a/src/Conftrack.hs b/src/Conftrack.hs
index d6e68e2..0d3ffdd 100644
--- a/src/Conftrack.hs
+++ b/src/Conftrack.hs
@@ -12,6 +12,8 @@ module Conftrack
, Warning(..)
, runFetchConfig
, readValue
+ , readOptionalValue
+ , readRequiredValue
, readNested
, SomeSource
, ConfigError(..)
@@ -54,8 +56,8 @@ runFetchConfig sources = do
unusedWarnings <- collectUnused sources
pure $ Right (result, origins, unusedWarnings <> warnings)
-readValue :: ConfigValue a => Key -> FetchMonad a
-readValue bareKey = do
+readOptionalValue :: ConfigValue a => Key -> FetchMonad (Maybe a)
+readOptionalValue bareKey = do
(sources, prefix, origins, warnings) <- get
let key = bareKey `prefixedWith` prefix
@@ -69,12 +71,26 @@ readValue bareKey = do
Left e -> Left e
val <- case fmap (\(Right a) -> a) $ NonEmpty.filter isRight values of
- [] -> lift $ throwE [NotPresent key]
- val:_ -> pure val
+ [] -> pure (Nothing, Origin key "default value")
+ (value, origin):_ -> pure (Just value, origin)
put (states, prefix, snd val : origins, warnings)
pure (fst val)
+readRequiredValue :: ConfigValue a => Key -> FetchMonad a
+readRequiredValue key =
+ readOptionalValue key >>= \case
+ Nothing -> lift $ throwE [NotPresent key]
+ Just a -> pure a
+
+readValue :: ConfigValue a => a -> Key -> FetchMonad a
+readValue defaultValue key =
+ readOptionalValue key >>= \case
+ Just a -> pure a
+ Nothing -> do
+ modify (\(states, prefix, origins, warnings) ->
+ (states, prefix, Origin key "default value" : origins, warnings))
+ pure defaultValue
firstMatchInSources :: Key -> [SomeSource] -> IO [(Either ConfigError (Value, Text), SomeSource)]
firstMatchInSources _ [] = pure []