5 files changed, 217 insertions(+), 0 deletions(-)

A Makefile
A README.md
A common/textwrap.go
A go.mod
A main.go

@@ 1,6 @@
+clean:
+	rm -rf textwrap
+
+build:
+	go build
+

@@ 1,59 @@
+# textwrap
+
+I have a variety of projects that:
+
+ * **need** a textwrapping library, even if it is overly simple
+ * **could benefit from** a thorough textwrapping library
+ * I want to work on **instead of** a thorough textwrapping library
+
+This package serves as:
+
+ * a handy utility
+ * a simple library that works for now
+ * a distribution mechanism for making incremental updates from a simple
+   library to a thorough one that all of my projects can benefit from
+
+
+## Development Status
+
+Very alpha
+
+
+## Usage (utility)
+
+```sh
+$ echo '12345' | textwrap -length 2
+12
+34
+5
+```
+
+
+## Usage (library)
+
+```go
+import (
+	"fmt"
+	"regexp"
+	textwrap "git.dominic-ricottone.com/textwrap/common"
+)
+
+func main() {
+	a := []string{
+		"> hello!",
+		"> this is quoted",
+		"hi there!",
+		"this is not",
+	}
+	for _, line := range textwrap.WrapArray(a,10) {
+		fmt.Println(line)
+	}
+}
+```
+
+
+## Licensing
+
+GPLv3
+
+

@@ 1,65 @@
+package common
+
+import (
+	"strings"
+	"regexp"
+)
+
+func MakeBreakline(length int) string {
+	return strings.Repeat("-", length)
+}
+
+func MakeWrappedLine(line string, length int, re_quote *regexp.Regexp) []string {
+	offset := 0
+	prefix := ""
+
+	quote := re_quote.FindString(line)
+	len_quote := len(quote)
+	if len_quote != 0 && len_quote < length {
+		offset = len_quote
+		prefix = quote
+	}
+
+	buffer := []string{prefix}
+	line_number := 0
+	for index, rune := range line[offset:] {
+		buffer[line_number] += string(rune)
+		if (index + 1) % (length - offset) == 0 {
+			buffer = append(buffer, prefix)
+			line_number += 1
+		}
+	}
+
+	return buffer
+}
+
+func WrapArray(lines []string, length int) ([]string, error) {
+	// Compile regular expressions
+	re_quote, err := regexp.Compile("^([> ]*)")
+	if err != nil {
+		return nil, err
+	}
+	re_break, err := regexp.Compile("^(?:-{5,}|={5,})$")
+	if err != nil {
+		return nil, err
+	}
+
+	wrapped := []string{}
+
+	for i := 0; i < len(lines); i++ {
+		line := strings.TrimSpace(lines[i])
+
+		if len(line) > length {
+			if re_break.MatchString(line) {
+				wrapped = append(wrapped, MakeBreakline(length))
+			} else {
+				wrapped = append(wrapped, MakeWrappedLine(line, length, re_quote)...)
+			}
+		} else {
+			wrapped = append(wrapped, line)
+		}
+	}
+
+	return wrapped, nil
+}
+

@@ 1,3 @@
+module git.dominic-ricottone.com/textwrap
+
+go 1.15

@@ 1,84 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"io"
+	"bufio"
+	"regexp"
+	"flag"
+
+	"git.dominic-ricottone.com/textwrap/common"
+)
+
+const LINE_LENGTH = 80
+
+func wrap_stream(reader io.Reader, length int) {
+	// Create scanner from reader
+	input := bufio.NewScanner(reader)
+
+	// Compile regular expressions
+	re_quote, err := regexp.Compile("^([> ]*)")
+	if err != nil {
+		fmt.Printf("internal error - %v\n", err)
+		os.Exit(1)
+	}
+	re_break, err := regexp.Compile("^(?:-{5,}|={5,})$")
+	if err != nil {
+		fmt.Printf("internal error - %v\n", err)
+		os.Exit(1)
+	}
+
+	// Scan line by line
+	for input.Scan() {
+		line := input.Text()
+		line = strings.TrimSpace(line)
+
+		if len(line) > length {
+			if re_break.MatchString(line) {
+				fmt.Printf("%s\n", common.MakeBreakline(length))
+			} else {
+				for _, wrapped := range common.MakeWrappedLine(line, length, re_quote) {
+					fmt.Printf("%s\n", wrapped)
+				}
+			}
+		} else {
+			fmt.Printf("%s\n", line)
+		}
+	}
+
+	// Check for scanner errors
+	if err = input.Err(); err != nil {
+		fmt.Printf("internal error - %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func wrap_file(filename string) {
+	// Check file
+	file, err := os.Open(filename)
+	if err != nil {
+		fmt.Printf("cannot read file '%s'\n", filename)
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	wrap_stream(file, LINE_LENGTH)
+}
+
+func main() {
+	// Check STDIN
+	_, err := os.Stdin.Stat()
+	if err != nil {
+		fmt.Println("cannot read input")
+		os.Exit(1)
+	}
+
+	// Look for arguments
+	var length = flag.Int("length", LINE_LENGTH, "maximum length of lines")
+	flag.Parse()
+
+	wrap_stream(os.Stdin, *length)
+}
+