URL parser

# title: URL parser
# source: https://rosettacode.org/wiki/URL_parser
# category: Rosetta Code
# difficulty: Intro
# summary: Parse a fixed URL into scheme, host, path, and query parameters.
# tags: popular, strings, parsing, hashes
# vibe: 0.2

def parse_query(text)
  if text == ""
    return []
  end

  parts = text.split("&")
  output = []
  index = 0

  while index < parts.length
    entry = parts[index].split("=")
    output = output.push({
      key: entry[0],
      value: entry[1]
    })
    index = index + 1
  end

  output
end

def parse_url(url)
  scheme_parts = url.split("://")
  scheme = scheme_parts[0]
  remainder = scheme_parts[1]

  slash_index = remainder.index("/")
  if slash_index == nil
    return { scheme: scheme, host: remainder, path: "", query: [] }
  end

  host = remainder.slice(0, slash_index)
  path_and_query = remainder.slice(slash_index, remainder.length - slash_index)
  question_index = path_and_query.index("?")

  if question_index == nil
    {
      scheme: scheme,
      host: host,
      path: path_and_query,
      query: []
    }
  else
    {
      scheme: scheme,
      host: host,
      path: path_and_query.slice(0, question_index),
      query: parse_query(path_and_query.slice(question_index + 1, path_and_query.length - question_index - 1))
    }
  end
end

def run
  parse_url("https://example.com/docs/guide?page=2&lang=en")
end