Commit Graph

21 Commits

Author SHA1 Message Date
Yehuda Katz
34292b282a Add support for ~ expansion
This ended up being a bit of a yak shave. The basic idea in this commit is to
expand `~` in paths, but only in paths.

The way this is accomplished is by doing the expansion inside of the code that
parses literal syntax for `SyntaxType::Path`.

As a quick refresher: every command is entitled to expand its arguments in a
custom way. While this could in theory be used for general-purpose macros,
today the expansion facility is limited to syntactic hints.

For example, the syntax `where cpu > 0` expands under the hood to
`where { $it.cpu > 0 }`. This happens because the first argument to `where`
is defined as a `SyntaxType::Block`, and the parser coerces binary expressions
whose left-hand-side looks like a member into a block when the command is
expecting one.

This is mildly more magical than what most programming languages would do,
but we believe that it makes sense to allow commands to fine-tune the syntax
because of the domain nushell is in (command-line shells).

The syntactic expansions supported by this facility are relatively limited.
For example, we don't allow `$it` to become a bare word, simply because the
command asks for a string in the relevant position. That would quickly
become more confusing than it's worth.

This PR adds a new `SyntaxType` rule: `SyntaxType::Path`. When a command
declares a parameter as a `SyntaxType::Path`, string literals and bare
words passed as an argument to that parameter are processed using the
path expansion rules. Right now, that only means that `~` is expanded into
the home directory, but additional rules are possible in the future.

By restricting this expansion to a syntactic expansion when passed as an
argument to a command expecting a path, we avoid making `~` a generally
reserved character. This will also allow us to give good tab completion
for paths with `~` characters in them when a command is expecting a path.

In order to accomplish the above, this commit changes the parsing functions
to take a `Context` instead of just a `CommandRegistry`. From the perspective
of macro expansion, you can think of the `CommandRegistry` as a dictionary
of in-scope macros, and the `Context` as the compile-time state used in
expansion. This could gain additional functionality over time as we find
more uses for the expansion system.
2019-08-26 21:03:24 -07:00
Yehuda Katz
0dc4b2b686 Add support for external escape valve (^dir)
This commit makes it possible to force nu to treat a command as an external command by prefixing it with `^`. For example `^dir` will force `dir` to run an external command, even if `dir` is also a registered nu command.

This ensures that users don't need to leave nu just because we happened to use a command they need.

This commit adds a new token type for external commands, which, among other things, makes it pretty straight forward to syntax highlight external commands uniquely, and generally to treat them as special.
2019-08-15 15:18:18 -07:00
Jonathan Turner
aadacc2d36 Merge master 2019-08-09 16:51:21 +12:00
Jonathan Turner
99671b8ffc Move more parts to tags and away from spans 2019-08-05 20:54:29 +12:00
Yehuda Katz
fc173c46d8 Restructuring 2019-08-02 12:15:07 -07:00
Jonathan Turner
462f783fac initial change to Tagged<Value> 2019-08-01 13:58:42 +12:00
Yehuda Katz
5a8e041a48 Tests pass! 2019-07-23 15:22:11 -07:00
Yehuda Katz
ded3462e82 Make signatures a little more general 2019-07-15 14:16:27 -07:00
Andrés N. Robalino
7e78bb4af5 Informs passing flags is unimplemented instead of quitting. 2019-07-13 22:39:41 -05:00
Yehuda Katz
711ed05b43 Produce ArgumentError for signature mismatch
ArgumentError also automatically produces diagnostics
2019-06-29 23:14:40 -07:00
Yehuda Katz
5cac3d1135 Fix lints 2019-06-29 09:32:58 -07:00
Yehuda Katz
3379c23a49 Support evaluating most expressions
Blocks, paths, and others

Plus a bunch of other infra improvements
2019-06-29 01:55:42 -07:00
Yehuda Katz
7957fc502f Fix a bunch of bugs 2019-06-23 18:55:31 -06:00
Yehuda Katz
bed5ba52d3 Fixed trailing issues 2019-06-23 15:36:01 -04:00
Yehuda Katz
cbab97174e Fix painting 2019-06-23 13:35:43 -04:00
Yehuda Katz
d0860837d2 Merge branch 'nom2' into nom4 2019-06-22 18:20:13 -04:00
Yehuda Katz
4036bf1ffd &str -> Text 2019-06-22 16:46:16 -04:00
Jonathan Turner
37c4fb92f8 Fix raw as a variable 2019-06-23 06:32:58 +12:00
Jonathan Turner
72a61f557b Remove debug println 2019-06-23 04:59:37 +12:00
Yehuda Katz
3b35dcb619 Finish nom upgrade 2019-06-22 10:08:53 -04:00
Yehuda Katz
e981129f1f Things work 2019-06-21 21:36:57 -04:00