Changelog of @hackage/mmzk-env 0.4.0.0

Revision history for mmzk-env

Breaking changes:

validateEnv, validateEnvWith, validateEnvW, validateEnvWWith, parseRecord, and parseRecordW now return Either ParseError a instead of Either String a. Code that matches on Left err where err :: String must be updated to use renderParseError err (or pattern-match on ParseError/FieldError).
TypeParser gains a new method parseMissing :: Either String a (default: Left "missing required environment variable"). Custom TypeParser instances that handled the empty-string case inside parseType to supply a default must move that logic to parseMissing — parseType "" is no longer called for absent environment variables.
TypeParserW gains a new method parseMissingW :: Proxy p -> Either String a (default: parseTypeW proxy ""). Custom TypeParserW instances that relied on parseTypeW proxy "" being called for absent variables are unaffected by the default; however, the same caveat as parseMissing applies if an instance overrides parseTypeW for the empty-string case.

New exports:

Data.Env.ParseError is now an exposed module exporting ParseError(..), FieldError(..), renderParseError, and renderFieldError. All are also re-exported from Data.Env.

Improved error messages:

All field failures are now collected in a single pass (no short-circuiting on the first error). ParseError is a list of FieldError values, one per failing field, in field-declaration order.
Missing required environment variables now produce "missing required environment variable" instead of a gigaparsec parse error on an empty string.
Base type parsers (String, Int, Word, Bool, numeric fixed-width types) now use P.label to produce readable expected-descriptions (e.g. expected an integer) instead of raw token expectations.
renderParseError formats errors with the field name on its own header line followed by the detail indented below; multiple failures are numbered.
EnumParser error messages now read invalid value "x"; expected one of: A, B, C instead of the previous format.

Fixed DefaultBool to follow the proper witness pattern:
- Changed from a newtype with TypeParser to a phantom type with TypeParserW.
- Added second type parameter (consistent with DefaultNum and DefaultString) enabling use with the Di type alias.
DefaultBool now accepts True, False, true, false, T, F, t, f, 1, 0.

Add the missing validateEnvW and validateEnvWWith functions for validating environment variables with witness types.
Add DefaultString witness type for providing default string values.
Add more texts and examples.

Witnessed record parsing (witness types carry type-level information that determines parsing behaviour):
- Add RecordParserW for witnessed record parsing.
- Add TypeParserW for witnessed type parsing.
- Add DefaultNum witness type for providing default numeric values.
Add convenient Maybe result variants for parsers.
Add runnable example executables in app/:
- quickstart-example: Basic environment validation example.
- enum-example: Enumerated type parsing example.
- newtype-example: Custom parser with newtype wrapper example.
- witness-example: Witness types with default values example.
Add more tests.
Heavy refactoring.

Added support for parsing enumerated types using EnumParser.
- Updated documentation to include examples of enum parsing.