Restored haskell syntax

It seems to work

helix-syntax/languages/tree-sitter-haskell

@@ -0,0 +1 @@
+Subproject commit 004f2709c460d95fbfd1061f8efc98f36e33c03c

helix-syntax/src/lib.rs

@@ -74,7 +74,7 @@ mk_langs!(
     (Css, tree_sitter_css),
     (Elixir, tree_sitter_elixir),
     (Go, tree_sitter_go),
-    // (Haskell, tree_sitter_haskell),
+    (Haskell, tree_sitter_haskell),
     (Html, tree_sitter_html),
     (Java, tree_sitter_java),
     (Javascript, tree_sitter_javascript),

languages.toml

@@ -144,3 +144,12 @@ file-types = ["php"]
 roots = []
 
 indent = { tab-width = 2, unit = "  " }
+
+[[language]]
+name = "haskell"
+scope = "source.haskell"
+injection-regex = "haskell"
+file-types = ["hs"]
+roots = []
+
+indent = { tab-width = 2, unit = "  " }

runtime/queries/haskell/highlights.scm

@@ -0,0 +1,43 @@
+(variable) @variable
+(operator) @operator
+(exp_name (constructor) @constructor)
+(constructor_operator) @operator
+(module) @module_name
+(type) @type
+(type) @class
+(constructor) @constructor
+(pragma) @pragma
+(comment) @comment
+(signature name: (variable) @fun_type_name)
+(function name: (variable) @fun_name)
+(constraint class: (class_name (type)) @class)
+(class (class_head class: (class_name (type)) @class))
+(instance (instance_head class: (class_name (type)) @class))
+(integer) @literal
+(exp_literal (float)) @literal
+(char) @literal
+(con_unit) @literal
+(con_list) @literal
+(tycon_arrow) @operator
+(where) @keyword
+"module" @keyword
+"let" @keyword
+"in" @keyword
+"class" @keyword
+"instance" @keyword
+"data" @keyword
+"newtype" @keyword
+"family" @keyword
+"type" @keyword
+"import" @keyword
+"qualified" @keyword
+"as" @keyword
+"deriving" @keyword
+"via" @keyword
+"stock" @keyword
+"anyclass" @keyword
+"do" @keyword
+"mdo" @keyword
+"rec" @keyword
+"(" @paren
+")" @paren

runtime/queries/haskell/locals.scm

@@ -0,0 +1,4 @@
+(signature name: (variable)) @local.definition
+(function name: (variable)) @local.definition
+(pat_name (variable)) @local.definition
+(exp_name (variable)) @local.reference