Kong supports limited variable interpolation into help strings, enum lists and
default values.
Variables are in the form:
${<name>}
Variables are set with the `Vars(map[string]string)` option. Undefined
variable references in the grammar will result in an error at construction
time.
Previously, there was a confusing mix of functionality shared between
the two wherein you would need to use the Kong type for printing errors,
etc. but it did not have access to the context in order to print
context-sensitive usage information. This has been fixed.
Additionally, there are now fuzzy correction suggestions for flags and
commands
Also added a server example which shows how Kong can be used for parsing
in interactive shells. Run with:
$ go run ./_examples/server/*.go
Then interact with:
$ ssh -p 6740 127.0.0.1
Map key/value separator is now hardcoded to `=`. This allows the
`sep` tag to continue to be used for slice separation, cascading to
support maps with slice values eg. `--set a=1,2,3`.
This allows accumulating mappers to work correctly. This also means
that resolvers are not even triggered if a command-line value is passed,
which is more desirable behaviour.
* Propagate errors.
* Use junit test output.
* Expand role of DecodeContext to include Scanner.
* Inject resolved flags as Path elements in the Context.
This allows all existing logic to apply seamlessly: hooks, required
flags, etc.
* Clarify that hooks can be called multiple times.
This allows help to be called even when the parse trace is invalid.
Without this, the command-line would have to be valid in order to use
help at all, which defeats the purpose.
* Add tracing to the parser.
* Synthesize a --help flag.
* Parsing now occurs in multiple phases.
1. Reset target.
2. Parse command-line into a "trace" (no values are written to target).
3. Apply traced, parsed values to the target fields.
This is another step in facilitating context-sensitive help and
completion.
* Detect duplicate flags.
This includes branching arguments as well as commands, eg.
app user create <id> <first> <last>
app user <id> delete
app user <id> rename <to>
Of note, required/optional flags and positional arguments are not
currently enforced.
Alec Thomas