You're seeing just the function ignore, go back to Ergo.Combinators module for more information.
Link to this function

ignore(parser, opts \\ [])

The ignore/1 parser matches but ignores the AST of its child parser.


iex> alias Ergo.Context
iex> import Ergo.{Terminals, Combinators}
iex> parser = sequence([literal("Hello"), ignore(ws()), literal("World")])
iex> context = Ergo.parse(parser, "Hello World")
iex> assert %Context{status: :ok, ast: ["Hello", "World"], index: 11, col: 12} = context