Semantic rust

[p-alik]

This PR aims to solve #130

Temporary Installation Step

semantic-rust depends on package tree-sitter-rust, which isn't available at https://hackage.haskell.org/ yet.

To build the content of this PR you've to execute following steps, because source-repository-package entry for haskell-tree-sitter (see a4410b6) doesn't solve .gitsubmodules dependency.

• cabal v2-update (or ./script/bootstrap)
• cd /tmp
• git clone --recurse-submodules git@github.com:tree-sitter/haskell-tree-sitter.git
• cd semantic
• find dist-newstyle/ -maxdepth 3 -type d -name "tree-sitter-rust" -exec cp -a ../haskell-tree-sitter/tree-sitter-rust/vendor {} \;
• cabal v2-buiild
• cd semantic-rust
• cabal v2-test (to get testing passed two corpus files were excluded e899938)

[joshvera]

Thanks @p-alik! I've uploaded tree-sitter-rust-0.1.0.0 to hackage so I think we can remove the source-repository-package entry.

Mind cherry-picking or doing something similar to this commit e18b6c3?

[p-alik]

Thank you for uploading of tree-sitter-rust-0.1.0.0 to hackage, @joshvera.
e18b6c3 was cherr-picked.
It seems there is no building/testing issue anymore, but since two corpus files are excluded a399bdd there remains some uncertainty because tree-sitter/tree-sitter#619 runs run corpus test properly.

[joshvera]

It seems there is no building/testing issue anymore, but since two corpus files are excluded a399bdd there remains some uncertainty because tree-sitter/tree-sitter#619 runs run corpus test properly.

That's alright we'll investigate later. I took a look briefly and it looks like an error parsing the macros.txt resulting in Error: "endOfInput". Might be an issue with our parsing or the file itself. https://github.com/github/semantic/blob/master/semantic-ast/src/AST/Test.hs#L77

[p-alik]

@joshvera, beside macros.txt a399bdd excludes expressions.txt for sake of this example, which fails with

    Match expressions:                                       FAIL
      src/AST/Test.hs:36:
      type 'MatchPattern' expected one or more nodes in field 'extraChildren' but got zero
      ```
      match x {
          1 => { "one" }
          2 => "two",
          -1 => 1,
          -3.14 => 3,

          #[attr1]
          3 => "three",
          macro!(4) => "four",
          _ => "something else",
      }   

      let msg = match x {
          0 | 1 | 10 => "one of zero, one, or ten",
          y if y < 20 => "less than 20, but not zero, one, or ten",
          y if y == 200 =>
            if a {
              "200 (but this is not very stylish)"
            } 
          _ => "something else",
      };  
      ```

[joshvera]

@p-alik thanks! I'll try to take a look soon.