COVER (melange.Js_parser.Pattern

let as_expression: 
  Parser_env.env =>
  Parser_common.pattern_cover =>
  Flow_ast.Expression.t(Loc.t, Loc.t);

let as_pattern: 
  ?err:Parse_error.t =>
  Parser_env.env =>
  Parser_common.pattern_cover =>
  Flow_ast.Pattern.t(Loc.t, Loc.t);

let empty_errors: Parser_common.pattern_errors;

let cons_error: 
  (Loc.t, Parse_error.t) =>
  Parser_common.pattern_errors =>
  Parser_common.pattern_errors;

let rev_append_errors: 
  Parser_common.pattern_errors =>
  Parser_common.pattern_errors =>
  Parser_common.pattern_errors;

let rev_errors: Parser_common.pattern_errors => Parser_common.pattern_errors;