* Document the lexer and lightly improve its names
The bulk of this pull request adds a substantial amount of new inline
documentation for the lexer. Along the way, I made a few minor changes
to the names in the lexer, most of which were internal.
The main change that affects other files is renaming `group` to `block`,
since the function is actually parsing a block (a list of groups).
* Further clean up the lexer
- Consolidate the logic of the various token builders into a single type
- Improve and clean up the event-driven BlockParser
- Clean up comment parsing. Comments now contain their original leading
whitespace as well as trailing whitespace, and know how to move some
leading whitespace back into the body based on how the lexer decides
to dedent the comments. This preserves the original whitespace
information while still making it straight-forward to eliminate leading
whitespace in help comments.
* Update meta.rs
* WIP
* fix clippy
* remove unwraps
* remove unwraps
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
Co-authored-by: Jonathan Turner <jonathan.d.turner@gmail.com>
* Add rest arg to def
This commit applied adds the ability to define the rest parameter of a def
command. It does not implement the functionality to expand the rest argument in
a user defined def function.
The rest argument has to be exactly worded "...rest".
Example after this PR is applied:
file test.nu
```shell
def my_command [
...rest:int # My rest arg
] {
echo 1 2 3
}
```
```shell
> source test.nu
> my_command -h
Usage:
> my_command ...args {flags}
Parameters:
...args: My rest arg
Flags:
-h, --help: Display this help message
```
* Fix space in help on wrong side
The completion engine maps completion locations to spans on a line, which
indicate whther to complete a command name, flag name, argument, and so on.
Initial implementation is simplistic, with some rough edges, since it relies
heavily on the parser's interpretation. For example
du -
if asking for completions, `-` is considered a positional argument by the
parser, but the user is likely looking for a flag. These scenarios will be
addressed in a series of progressive enhancements to the engine.
* Delete unnecessary match
* Use `unwrap_or_else()`
* Whitespace was trim on file save
* Use `map_or_else()`
* Use a default to group all match arms with same output
* Clippy made me do it
* Add some docs for meta.rs
* add better explanation for Span merging
* Add some doc tests - not sure how to get them to run
* get rid of doc comments for the temporary method
* add doc test for is_unknown
* fmt
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>
* Clippy fixes
* Finish converting to use clippy
* fix warnings in new master
* fix windows
* fix windows
Co-authored-by: Artem Vorotnikov <artem@vorotnikov.me>
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 Tag, Span, Text, as well as source-related debug
facilities into a new crate called nu_source.
This change is much bigger than one might have expected because the
previous code relied heavily on implementing inherent methods on
`Tagged<T>` and `Spanned<T>`, which is no longer possible.
As a result, this change creates more concrete types instead of using
`Tagged<T>`. One notable example: Tagged<Value> became Value, and Value
became UntaggedValue.
This change clarifies the intent of the code in many places, but it does
make it a big change.
