update grammar

README.md

@@ -1,47 +1,41 @@
-# tree-sitter-nu
-
-This is an experiment to see if we can create a good parser for nu-lang.
-
-## Goals (brainstorming)
-
-- Ability to serve as a parser for a repl
-- Ability to work in editors that support tree-sitter (`hx`, `nvim`, others)
-- Ability to work in rust
-- Fast
-- Ability to be utilized for syntax highlighting
-- ?
-
-## How-To - taken from [here](https://tree-sitter.github.io/tree-sitter/creating-parsers)
-
-1. `cargo install tree-sitter-cli`
-2. make sure nodejs and npm is installed (you may have to do npm install - see docs above)
-3. `tree-sitter generate`
-4. `tree-sitter parse example-file.nu`
-
-## Examples with rust
-
-1. main.rs
-2. `cargo run --example main`
-
-## Testing
-
-1. Add a file to test/corpus/descriptive_test_name.txt
-2. Use the `custom_command_1.txt` as a guide
-3. run `tree-sitter test -f 'custom command 1'` and evaluate the results
-4. More information can be found [here](https://tree-sitter.github.io/tree-sitter/creating-parsers#command-test)
-
-## Tips
-
-- A line in the grammar.js that begins with `$._blah` means that `blah` is anonymous and won't show up in the final syntax tree.
-- Most of the grammar how-to is found [here](https://tree-sitter.github.io/tree-sitter/creating-parsers#the-grammar-dsl)
-
-## Further reading
-
-- https://siraben.dev/2022/03/22/tree-sitter-linter.html
-- https://derek.stride.host/posts/comprehensive-introduction-to-tree-sitter
-
-- https://tree-sitter.github.io/tree-sitter/
-- https://rfdonnelly.github.io/posts/using-tree-sitter-parsers-in-rust/
-- https://deepsource.io/blog/lightweight-linting/
-- https://github.com/tree-sitter/tree-sitter/issues/418
-- https://github.com/DerekStride/tree-sitter-math
+# tree-sitter nu
+
+[**WIP**] [nushell](https://github.com/nushell/nushell) grammar for [tree-sitter](https://tree-sitter.github.io/tree-sitter/)
+
+# issues
+1. unquoted strings
+```nu
+# this should parse as a pipeline with two elements
+'nushell' | str contains n
+
+# but it is parsed as two pipelines, with one ending
+# at `contains`
+'nushell' | str contains
+n
+
+# quoting the string solves it though
+'nushell' | str contains 'n' # <- okay
+```
+
+2. blocks vs records
+since we cannot backtrack, it is difficult to tell apart blocks and
+records. so currently, blocks are not parsed as values
+```nu
+# this will not parse
+ls | each { $in + 4 }
+
+# however this parses
+ls | each {|it| $it + 4 }
+```
+
+3. cellpaths with numbers
+```nu
+ls | $in.4 # does not parse
+```
+
+4. command arguments are parsed as strings
+```nu
+some-cmd 2 -f arg
+```
+
+here `2`, `-f`, `arg` will all be parsed as strings