The sequence/2 parser takes a list of parsers which are applied in turn. If any of the parsers fails the sequence itself fails.

The sequence/2 parser treats the commit/0 parser differently. When it sees commit it increments the contexts commit count. When the parser is complete, if it has increased the commit count it decrements it before returning it. See also many

Examples

iex> alias Ergo.Context
iex> import Ergo.{Terminals, Combinators}
iex> parser = sequence([literal("Hello"), ws(), literal("World")])
iex> context = Ergo.parse(parser, "Hello World")
%Context{status: :ok, ast: ["Hello", ?\s, "World"], index: 11, line: 1, col: 12} = context

This test will need to be rewritten in terms of Ergo.diagnose
# iex> Logger.disable(self())
# iex> alias Ergo.Context
# iex> import Ergo.{Terminals, Combinators}
# iex> parser = sequence([literal("Hello"), ws(), literal("World")], label: "HelloWorld")
# iex> context = Ergo.parse(parser, "Hello World")
# iex> assert %Context{status: :ok, ast: ["Hello", ?\s, "World"], index: 11, line: 1, col: 12} = context

iex> alias Ergo.Context
iex> import Ergo.{Terminals, Combinators}
iex> parser = sequence([literal("Hello"), ws(), literal("World")], ast: fn ast -> Enum.join(ast, " ") end)
iex> context = Ergo.parse(parser, "Hello World")
iex> assert %Context{status: :ok, ast: "Hello 32 World", index: 11, line: 1, col: 12} = context

This test will need to be rewritten in terms of Ergo.diagnose
# iex> Logger.disable(self())
# iex> alias Ergo.Context
# iex> import Ergo.{Terminals, Combinators}
# iex> parser = sequence([literal("Hello"), ws(), literal("World")], label: "HelloWorld", ast: fn ast -> Enum.join(ast, " ") end)
# iex> context = Ergo.parse(parser, "Hello World")
# iex> assert %Context{status: :ok, ast: "Hello 32 World", index: 11, line: 1, col: 12} = context

iex> alias Ergo.Context
iex> import Ergo.{Combinators, Terminals}
iex> parser = sequence([literal("foo"), ws(), literal("bar")])
iex> assert %Context{status: {:error, [{:bad_literal, _, _}, {:unexpected_char, _, _}]}} = Ergo.parse(parser, "Hello World")