nl

Documentation

Overview

Package nl provides line break characters for multiple system and microcomputer platforms.

Index

• Constants
• Variables
• func Lines(r io.Reader, lb [2]rune) (int, error)
• func NewLine(s System) string
• type LineBreak
  • func (lb *LineBreak) Find(r [2]rune)
  • func (lb *LineBreak) Total(name string) (int, error)
• type System

Examples

• LineBreak.Find
• LineBreak.Total
• NewLine

Constants

const (
	LF  rune = 10  // LF is the control code for a line feed.
	CR  rune = 13  // CR is the control code for a carriage return.
	NL  rune = 21  // NL is the control code for a new line, an EBCDIC control.
	NEL rune = 133 // NEL is the control code for a next line.
)

Common ASCII and EBCDIC control codes for new lines.

Variables

var ErrReader = errors.New("the r reader cannot be nil")

Functions

func Lines

func Lines(r io.Reader, lb [2]rune) (int, error)

Lines counts the number of lines in the interface. The lb rune pair is the line break sequence. If the line break only has one rune, then the second rune should be 0.

func NewLine

func NewLine(s System) string

NewLine returns a new line or line break characters for the system platform.

Example

package main

import (
	"fmt"

	"github.com/bengarrett/retrotxtgo/nl"
)

func main() {
	s := nl.NewLine(nl.Windows)
	fmt.Printf("%q\n", s)
	s = nl.NewLine(nl.Macintosh)
	fmt.Printf("%q\n", s)
	s = nl.NewLine(nl.Linux)
	fmt.Printf("%q\n", s)
}

Output:

"\r\n"
"\r"
"\n"

Types

type LineBreak

type LineBreak struct {
	Abbr    string  `json:"string"  xml:"string,attr"` // Abbr is the abbreviation for the line break.
	Escape  string  `json:"escape"  xml:"-"`           // Escape is the escape sequence for the line break.
	Decimal [2]rune `json:"decimal" xml:"decimal"`     // Decimal is the numeric character code for the line break.
}

LineBreak contains details on the line break sequence used to create a new line in a text file.

func (*LineBreak) Find

func (lb *LineBreak) Find(r [2]rune)

Find determines the new lines characters found in the rune pair.

Example

package main

import (
	"fmt"

	"github.com/bengarrett/retrotxtgo/nl"
)

func main() {
	lb := &nl.LineBreak{}

	// A Windows example of a line break.
	windows := [2]rune{rune('\r'), rune('\n')}
	lb.Find(windows)
	fmt.Printf("%s %q %d %X\n", lb.Abbr, lb.Escape, lb.Decimal, lb.Decimal)

	// A macOS, Linux, or Unix example of a line break.
	linux := [2]rune{rune('\n')}
	lb.Find(linux)
	fmt.Printf("%s %q %d %X\n", lb.Abbr, lb.Escape, lb.Decimal, lb.Decimal)

}

Output:

CRLF "\r\n" [13 10] [D A]
LF "\n" [10 0] [A 0]

func (*LineBreak) Total

func (lb *LineBreak) Total(name string) (int, error)

Total counts the number of lines in the named file based on the provided line break sequence.

Example

package main

import (
	"fmt"

	"github.com/bengarrett/retrotxtgo/nl"
)

func main() {
	lb := &nl.LineBreak{}
	linux := [2]rune{rune('\n')}
	lb.Find(linux)
	// Count the number of lines in a file.
	total, _ := lb.Total("testdata/textlf.txt")
	fmt.Println(total)
}

Output:

7

type System

type System int

System is a micro or computer platform.

const (
	Host      System = iota // Host is the host operating system default.
	Acorn                   // Acorn is the Acorn Archimedes.
	Amiga                   // Amiga is the Commodore Amiga.
	Commodore               // Commodore is the Commodore 64 and compatibles.
	Darwin                  // Darwin is Apple macOS.
	Linux                   // Linux is the Linux operating system.
	Macintosh               // Macintosh is the Apple Macintosh.
	PCDos                   // PCDos is an IBM PC and Microsoft DOS and compatibles.
	Unix                    // Unix are both Unix and BSD.
	Windows                 // Windows is Microsoft Windows.
)