Added ToCSV

csv.go

@@ -1,11 +1,38 @@
 package scriptx
 
 import (
+	"bufio"
 	"encoding/csv"
 	"errors"
 	"io"
 )
 
+type Splitter interface {
+	Split(line string, n int) []string
+}
+
+// ToCSV is a filter function that reads the source as a series of lines, splits them
+// into tokens using the passed in Splitter, and writes them to the output as a CSV.
+func ToCSV(splitter Splitter) func(io.Reader, io.Writer) error {
+	return func(r io.Reader, w io.Writer) error {
+		csvWriter := csv.NewWriter(w)
+
+		scnr := bufio.NewScanner(r)
+		for scnr.Scan() {
+			line := scnr.Text()
+			if err := csvWriter.Write(splitter.Split(line, -1)); err != nil {
+				return err
+			}
+		}
+		if err := scnr.Err(); err != nil {
+			return err
+		}
+
+		csvWriter.Flush()
+		return nil
+	}
+}
+
 // CSVColumn is a filter function that reads the source as a CSV file and extracts the cell
 // values of the named column, excluding the header itself. If the column cannot be found,
 // the filter will produce nothing. If the column index is beyond the number of columns

csv_test.go

@@ -1,6 +1,7 @@
 package scriptx_test
 
 import (
+	"regexp"
 	"testing"
 
 	"github.com/bitfield/script"
@@ -42,3 +43,17 @@ func ExampleCSVColumn() {
 	// banana
 	// cherry
 }
+
+func ExampleToCSV() {
+	script.Slice([]string{
+		"letter  fruit   word",
+		"a       apple   alpha",
+		"b       banana  bravo",
+		"c       cherry  charlie",
+	}).Filter(scriptx.ToCSV(regexp.MustCompile(`\s+`))).Stdout()
+	// Output:
+	// letter,fruit,word
+	// a,apple,alpha
+	// b,banana,bravo
+	// c,cherry,charlie
+}