public trim(value: Text) (result: Text) {
  result = dever.system.text_trim(value)
}

public lower(value: Text) (result: Text) {
  result = dever.system.text_lower(value)
}

public upper(value: Text) (result: Text) {
  result = dever.system.text_upper(value)
}

public codepoint(value: Text) (result: Int?) {
  result = dever.system.text_codepoint(value)
}

public from_codepoint(value: Int) (result: Text?) {
  result = dever.system.text_from_codepoint(value)
}

public at(value: Text, index: Int) (result: Text?) {
  result = dever.system.text_at(value, index)
}

public slice(value: Text, start: Int, end: Int) (result: Text?) {
  result = dever.system.text_slice(value, start, end)
}

public index_of(value: Text, pattern: Text) (result: Int?) {
  result = dever.system.text_index_of(value, pattern)
}

public contains(value: Text, pattern: Text) (result: Bool) {
  result = dever.system.text_contains(value, pattern)
}

public starts_with(value: Text, prefix: Text) (result: Bool) {
  result = dever.system.text_starts_with(value, prefix)
}

public ends_with(value: Text, suffix: Text) (result: Bool) {
  result = dever.system.text_ends_with(value, suffix)
}

public split(value: Text, separator: Text) (result: List<Text>) {
  result = dever.system.text_split(value, separator)
}

public replace(value: Text, pattern: Text, replacement: Text) (result: Text) {
  result = dever.system.text_replace(value, pattern, replacement)
}

public is_empty(value: Text) (result: Bool) {
  result = length(value) == 0
}

type JoinState {
  text: Text
  separator: Text
  first: Bool
}

public join(values: List<Text>, separator: Text) (result: Text) {
  state = reduce(
    join_piece,
    values,
    JoinState {
      text = ""
      separator = separator
      first = true
    }
  )
  result = state.text
}

join_piece(value: Text, state: JoinState) (result: JoinState) {
  result = join_next(state.first, value, state)
}

join_next(first: true, value: Text, state: JoinState) (result: JoinState) {
  result = state
  result.text = value
  result.first = false
}

join_next(first: false, value: Text, state: JoinState) (result: JoinState) {
  result = state
  result.text = state.text + state.separator + value
}