philomena/lib/search/float_parser.ex

38 lines
1 KiB
Elixir

defmodule Search.FloatParser do
import NimbleParsec
defp to_number(input), do: Search.Helpers.to_number(input)
defp range(input), do: Search.Helpers.range(input)
space =
choice([string(" "), string("\t"), string("\n"), string("\r"), string("\v"), string("\f")])
|> ignore()
fuzz =
string("~")
|> ignore()
unsigned_float =
ascii_string([?0..?9], min: 1)
|> optional(ascii_char('.') |> ascii_string([?0..?9], min: 1))
|> reduce({List, :to_string, []})
|> reduce(:to_number)
float =
optional(ascii_char('-+'))
|> ascii_string([?0..?9], min: 1)
|> optional(ascii_char('.') |> ascii_string([?0..?9], min: 1))
|> reduce({List, :to_string, []})
|> reduce(:to_number)
float_parser =
choice([
float |> concat(fuzz) |> concat(unsigned_float) |> reduce(:range) |> unwrap_and_tag(:float_range),
float |> unwrap_and_tag(:float)
])
|> repeat(space)
|> eos()
|> label("a real number, like `2.7182818' or `-10'")
defparsec :parse, float_parser
end