feat: add HelixQL parser

Add parser, queries, and tests for HelixQL (helix-db.com), a SQL-like query language for HelixDB.

runtime/queries/helixql/folds.scm

@@ -0,0 +1,12 @@
+; =============================================================================
+; HelixQL Folds for Neovim Tree-sitter
+; =============================================================================
+[
+  (node_def)
+  (edge_def)
+  (vector_def)
+  (query_def)
+  (for_loop)
+  (object_step)
+  (create_field)
+] @fold

runtime/queries/helixql/highlights.scm

@@ -0,0 +1,259 @@
+; =============================================================================
+; HelixQL Syntax Highlighting for Neovim Tree-sitter
+; =============================================================================
+; NOTE: In tree-sitter queries, later patterns override earlier ones.
+; Put general patterns first, then specific overrides after.
+; -----------------------------------------------------------------------------
+; Comments
+; -----------------------------------------------------------------------------
+(comment) @comment @spell
+
+; -----------------------------------------------------------------------------
+; Literals
+; -----------------------------------------------------------------------------
+(string_literal) @string
+
+(integer) @number
+
+(float) @number.float
+
+(boolean) @boolean
+
+(none) @constant.builtin
+
+(now) @constant.builtin
+
+; -----------------------------------------------------------------------------
+; Generic identifiers
+; -----------------------------------------------------------------------------
+(identifier) @variable
+
+(identifier_upper) @type
+
+; -----------------------------------------------------------------------------
+; Keywords
+; -----------------------------------------------------------------------------
+[
+  "QUERY"
+  "RETURN"
+  "FOR"
+  "IN"
+] @keyword
+
+; Node type keywords (wrapped in their own rules)
+(index) @keyword
+
+(default) @keyword
+
+(count) @keyword
+
+(ID) @constant.builtin
+
+; Keywords inside node types
+(where_step
+  "WHERE" @keyword)
+
+(range_step
+  "RANGE" @keyword)
+
+(update
+  "UPDATE" @keyword)
+
+(drop
+  "DROP" @keyword)
+
+(exists
+  "EXISTS" @keyword)
+
+; Boolean and logical operators
+(and
+  "AND" @keyword.operator)
+
+(or
+  "OR" @keyword.operator)
+
+(GT
+  "GT" @keyword.operator)
+
+(GTE
+  "GTE" @keyword.operator)
+
+(LT
+  "LT" @keyword.operator)
+
+(LTE
+  "LTE" @keyword.operator)
+
+(EQ
+  "EQ" @keyword.operator)
+
+(NEQ
+  "NEQ" @keyword.operator)
+
+; Creation operation keywords
+(AddN
+  "AddN" @function.builtin)
+
+(AddE
+  "AddE" @function.builtin)
+
+(AddV
+  "AddV" @function.builtin)
+
+(BatchAddV
+  "BatchAddV" @function.builtin)
+
+(search_vector
+  "SearchV" @function.builtin)
+
+; -----------------------------------------------------------------------------
+; Schema definition keywords
+; -----------------------------------------------------------------------------
+[
+  "N::"
+  "E::"
+  "V::"
+] @keyword.directive
+
+[
+  "From:"
+  "To:"
+  "Properties"
+] @keyword.modifier
+
+; -----------------------------------------------------------------------------
+; Graph traversal methods
+; -----------------------------------------------------------------------------
+(out_e
+  "OutE" @function.method)
+
+(in_e
+  "InE" @function.method)
+
+(from_n) @function.method
+
+(to_n) @function.method
+
+(out
+  "Out" @function.method)
+
+(in_nodes
+  "In" @function.method)
+
+(shortest_path
+  "ShortestPath" @function.method)
+
+; -----------------------------------------------------------------------------
+; Start nodes - highlight N, E, V as keywords
+; -----------------------------------------------------------------------------
+(start_node
+  "N" @keyword)
+
+(start_edge
+  "E" @keyword)
+
+(start_vector
+  "V" @keyword)
+
+; -----------------------------------------------------------------------------
+; Types
+; -----------------------------------------------------------------------------
+(named_type) @type.builtin
+
+(date_type) @type.builtin
+
+(ID_TYPE) @type.builtin
+
+; Type arguments in angle brackets
+(type_args
+  (identifier_upper) @type)
+
+; -----------------------------------------------------------------------------
+; Specific identifier patterns (override generic rules)
+; -----------------------------------------------------------------------------
+; Query/function names
+(query_def
+  name: (identifier) @function)
+
+; Schema definition names
+(node_def
+  name: (identifier_upper) @type.definition)
+
+(edge_def
+  name: (identifier_upper) @type.definition)
+
+(vector_def
+  name: (identifier_upper) @type.definition)
+
+; Parameter names in function signatures
+(param_def
+  name: (identifier) @variable.parameter)
+
+; Field names in schema definitions
+(field_def
+  name: (identifier) @property)
+
+; Property keys in object creation
+(new_field
+  key: (identifier) @property)
+
+; Property keys in updates
+(update_field
+  key: (identifier) @property)
+
+; Property keys in object mapping (left of :)
+(mapping_field
+  (identifier) @property
+  ":")
+
+; Object access field
+(object_access
+  field: (identifier) @property)
+
+; Variable assignment targets (left of <-)
+(get_stmt
+  variable: (identifier) @variable)
+
+; For loop iterable
+(for_loop
+  iterable: (identifier) @variable)
+
+; -----------------------------------------------------------------------------
+; Operators
+; -----------------------------------------------------------------------------
+[
+  "<-"
+  "=>"
+  "::"
+  "."
+  ".."
+  "!"
+] @operator
+
+; -----------------------------------------------------------------------------
+; Punctuation
+; -----------------------------------------------------------------------------
+[
+  ":"
+  ","
+] @punctuation.delimiter
+
+[
+  "("
+  ")"
+  "{"
+  "}"
+  "["
+  "]"
+  "<"
+  ">"
+] @punctuation.bracket
+
+"|" @punctuation.special
+
+; -----------------------------------------------------------------------------
+; Special patterns
+; -----------------------------------------------------------------------------
+; Anonymous traversal underscore
+(anonymous_traversal
+  "_" @variable.builtin)