Clive, 2nd ed. User's manual. Section 2 
SYNOPSYS

import "clive/cmd/wr/frmt"

const Left = false ...
const Esc = "\001" ...
const NoBlankLines ParFmt = iota ...
func Fmt(wc <-chan []rune, wid int, right bool, keeplines ParFmt) <-chan []rune
func Words() (chan<- string, <-chan []rune)
type ParFmt int

DESCRIPTION

CONSTANTS

const (
	Left = false // left-justify only
	Both = true  // justify both margins
)
    1st arg to Fmt

const (
	Esc   = "\001" // start of raw word escape
	NoEsc = "\002" // end of raw word escape
)
    Escapes can be used to handle a portion of text as a single word. They are
    also written to the output and, if used, requires the caller to remove them
    before presenting data to the user.

TYPES

type ParFmt int
    2nd arg to Fmt

const (
	NoBlankLines  ParFmt = iota // format everything as a single par
	OneBlankLine                // output one empty line between pars
	AllBlankLines               // keep all empty lines between pars
)

FUNCTIONS

func Fmt(wc <-chan []rune, wid int, right bool, keeplines ParFmt) <-chan []rune
    Given a chan as the output of Words(), return a chan to read lines from it
    so that each line is at most n runes wide. This eats most of the white space
    including empty lines. Justify also the right margin if right is true. If
    keeplines is true, runs of empty lines are not eated, but replaced with a
    single empty line.

func Words() (chan<- string, <-chan []rune)
    Given a chan where we send strings, return a chan to get separate words and
    white-space runs.

User's manual, 2nd ed. Section 2