* Add failing test that list of ints and floats is List<Number>
* Start defining subtype relation
* Make it possible to declare input and output types for commands
- Enforce them in tests
* Declare input and output types of commands
* Add formatted signatures to `help commands` table
* Revert SyntaxShape::Table -> Type::Table change
* Revert unnecessary derive(Hash) on SyntaxShape
Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>
* remove unnecessary FlatShape
* add proptest
* remove files that belonged in another PR
* more tests, more chars
* add exception for parser error unrelated ot PR
* Ignore `cargo tarpaulin` output files
* Add expected result for `columns` example
Examples without provided expected output will never be tested.
The subset of commands available in `test_examples()` is limited thus
excluding the tests depending on other commands
* Add example test harness to `reject`
* Test and fix `wrap` example
* Test and fix `drop column` example
* Update `from ods` examples
* Update `from xlsx` examples
* Run `to nuon` examples
* Run `hash base64` examples
* Add example output to `path parse`
* Test and fix the `grid` examples
