Restructure and streamline token expansion
The purpose of this commit is to streamline the token expansion code, by
removing aspects of the code that are no longer relevant, removing
pointless duplication, and eliminating the need to pass the same
arguments to `expand_syntax`.
The first big-picture change in this commit is that instead of a handful
of `expand_` functions, which take a TokensIterator and ExpandContext, a
smaller number of methods on the `TokensIterator` do the same job.
The second big-picture change in this commit is fully eliminating the
coloring traits, making coloring a responsibility of the base expansion
implementations. This also means that the coloring tracer is merged into
the expansion tracer, so you can follow a single expansion and see how
the expansion process produced colored tokens.
One side effect of this change is that the expander itself is marginally
more error-correcting. The error correction works by switching from
structured expansion to `BackoffColoringMode` when an unexpected token
is found, which guarantees that all spans of the source are colored, but
may not be the most optimal error recovery strategy.
That said, because `BackoffColoringMode` only extends as far as a
closing delimiter (`)`, `]`, `}`) or pipe (`|`), it does result in
fairly granular correction strategy.
The current code still produces an `Err` (plus a complete list of
colored shapes) from the parsing process if any errors are encountered,
but this could easily be addressed now that the underlying expansion is
error-correcting.
This commit also colors any spans that are syntax errors in red, and
causes the parser to include some additional information about what
tokens were expected at any given point where an error was encountered,
so that completions and hinting could be more robust in the future.
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
Co-authored-by: Andrés N. Robalino <andres@androbtech.com>
* WIP --help works for PerItemCommands.
* De-linting
* Add more comments (#1228)
* Add some more docs
* More docs
* More docs
* More docs (#1229)
* Add some more docs
* More docs
* More docs
* Add more docs
* External commands: wrap values that contain spaces in quotes (#1214) (#1220)
* External commands: wrap values that contain spaces in quotes (#1214)
* Add fn's argument_contains_whitespace & add_quotes (#1214)
* Fix formatting with cargo fmt
* Don't wrap argument in quotes when $it is already quoted (#1214)
* Implement --help for internal commands
* Externals now spawn independently. (#1230)
This commit changes the way we shell out externals when using the `"$it"` argument. Also pipes per row to an external's stdin if no `"$it"` argument is present for external commands.
Further separation of logic (preparing the external's command arguments, getting the data for piping, emitting values, spawning processes) will give us a better idea for lower level details regarding external commands until we can find the right abstractions for making them more generic and unify within the pipeline calling logic of Nu internal's and external's.
* Poll externals quicker. (#1231)
* WIP --help works for PerItemCommands.
* De-linting
* Implement --help for internal commands
* Make having --help the default
* Update test to include new default switch
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
Co-authored-by: Koenraad Verheyden <mail@koenraadverheyden.com>
Co-authored-by: Andrés N. Robalino <andres@androbtech.com>
This commit contains two improvements:
- Support for a Range syntax (and a corresponding Range value)
- Work towards a signature syntax
Implementing the Range syntax resulted in cleaning up how operators in
the core syntax works. There are now two kinds of infix operators
- tight operators (`.` and `..`)
- loose operators
Tight operators may not be interspersed (`$it.left..$it.right` is a
syntax error). Loose operators require whitespace on both sides of the
operator, and can be arbitrarily interspersed. Precedence is left to
right in the core syntax.
Note that delimited syntax (like `( ... )` or `[ ... ]`) is a single
token node in the core syntax. A single token node can be parsed from
beginning to end in a context-free manner.
The rule for `.` is `<token node>.<member>`. The rule for `..` is
`<token node>..<token node>`.
Loose operators all have the same syntactic rule: `<token
node><space><loose op><space><token node>`.
The second aspect of this pull request is the beginning of support for a
signature syntax. Before implementing signatures, a necessary
prerequisite is for the core syntax to support multi-line programs.
That work establishes a few things:
- `;` and newlines are handled in the core grammar, and both count as
"separators"
- line comments begin with `#` and continue until the end of the line
In this commit, multi-token productions in the core grammar can use
separators interchangably with spaces. However, I think we will
ultimately want a different rule preventing separators from occurring
before an infix operator, so that the end of a line is always
unambiguous. This would avoid gratuitous differences between modules and
repl usage.
We already effectively have this rule, because otherwise `x<newline> |
y` would be a single pipeline, but of course that wouldn't work.
`left =~ right` return true if left contains right, using Rust's
`String::contains`. `!~` is the negated version.
A new `apply_operator` function is added which decouples evaluation from
`Value::compare`. This returns a `Value` and opens the door to
implementing `+` for example, though it wouldn't be useful immediately.
The `operator!` macro had to be changed slightly as it would choke on
`~` in arguments.
This commit extracts five new crates:
- nu-source, which contains the core source-code handling logic in Nu,
including Text, Span, and also the pretty.rs-based debug logic
- nu-parser, which is the parser and expander logic
- nu-protocol, which is the bulk of the types and basic conveniences
used by plugins
- nu-errors, which contains ShellError, ParseError and error handling
conveniences
- nu-textview, which is the textview plugin extracted into a crate
One of the major consequences of this refactor is that it's no longer
possible to `impl X for Spanned<Y>` outside of the `nu-source` crate, so
a lot of types became more concrete (Value became a concrete type
instead of Spanned<Value>, for example).
This also turned a number of inherent methods in the main nu crate into
plain functions (impl Value {} became a bunch of functions in the
`value` namespace in `crate::data::value`).
