From 19446235e0874948e88769e7bdcd30d95585e8bc Mon Sep 17 00:00:00 2001
From: Leon Mika <lmika@lmika.org>
Date: Mon, 24 Apr 2023 01:29:54 +0000
Subject: [PATCH] Initial commit

---
 csv.go     | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 fmt.go     | 19 +++++++++++++++++++
 go.mod     |  3 +++
 scriptx.go | 22 ++++++++++++++++++++++
 subpipe.go | 33 +++++++++++++++++++++++++++++++++
 5 files changed, 126 insertions(+)
 create mode 100644 csv.go
 create mode 100644 fmt.go
 create mode 100644 go.mod
 create mode 100644 scriptx.go
 create mode 100644 subpipe.go

diff --git a/csv.go b/csv.go
new file mode 100644
index 0000000..072dcde
--- /dev/null
+++ b/csv.go
@@ -0,0 +1,49 @@
+package scriptx
+
+import (
+	"encoding/csv"
+	"errors"
+	"io"
+)
+
+func CSVColumn(name string) func(r io.Reader, w io.Writer) error {
+	return func(r io.Reader, w io.Writer) error {
+		cr := csv.NewReader(r)
+
+		header, err := cr.Read()
+		if err != nil {
+			return err
+		}
+
+		var colIdx = -1
+		for i, ch := range header {
+			if ch == name {
+				colIdx = i
+			}
+		}
+		if colIdx == -1 {
+			return nil
+		}
+
+		for {
+			rec, err := cr.Read()
+			if err != nil {
+				if errors.Is(err, io.EOF) {
+					return nil
+				} else {
+					return err
+				}
+			}
+			if len(rec) < colIdx {
+				continue
+			}
+
+			if _, err := io.WriteString(w, rec[colIdx]); err != nil {
+				return err
+			}
+			if _, err := w.Write([]byte{'\n'}); err != nil {
+				return err
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/fmt.go b/fmt.go
new file mode 100644
index 0000000..897a91a
--- /dev/null
+++ b/fmt.go
@@ -0,0 +1,19 @@
+package scriptx
+
+import (
+	"fmt"
+	"io"
+)
+
+func Printf(ptrn string) func(r io.Reader, w io.Writer) error {
+	return func(r io.Reader, w io.Writer) error {
+		return eachLine(r, func(line string) error {
+			_, err := io.WriteString(w, fmt.Sprintf(ptrn, line))
+			if err != nil {
+				return err
+			}
+			_, err = w.Write([]byte{'\n'})
+			return err
+		})
+	}
+}
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..cf027b6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/lmika/scriptx
+
+go 1.20
diff --git a/scriptx.go b/scriptx.go
new file mode 100644
index 0000000..9c2fc9a
--- /dev/null
+++ b/scriptx.go
@@ -0,0 +1,22 @@
+package scriptx
+
+import (
+	"encoding/json"
+	"io"
+)
+
+func ToJSON(fn func(line string) any) func(r io.Reader, w io.Writer) error {
+	return func(r io.Reader, w io.Writer) error {
+		return eachLine(r, func(line string) (err error) {
+			jsonBytes, err := json.Marshal(fn(line))
+			if err != nil {
+				return err
+			}
+			if _, err = w.Write(jsonBytes); err != nil {
+				return err
+			}
+			_, err = w.Write([]byte{'\n'})
+			return err
+		})
+	}
+}
\ No newline at end of file
diff --git a/subpipe.go b/subpipe.go
new file mode 100644
index 0000000..738e02e
--- /dev/null
+++ b/subpipe.go
@@ -0,0 +1,33 @@
+package scriptx
+
+import (
+	"bufio"
+	"github.com/bitfield/script"
+	"io"
+)
+
+func eachLine(r io.Reader, fn func(line string) error) error {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		if err := fn(scanner.Text()); err != nil {
+			return err
+		}
+	}
+	return scanner.Err()
+}
+
+func SubPipe(fn func(src string) *script.Pipe) func(r io.Reader, w io.Writer) error {
+	return func(r io.Reader, w io.Writer) error {
+		scanner := bufio.NewScanner(r)
+		for scanner.Scan() {
+			bts, err := fn(scanner.Text()).Bytes()
+			if err != nil {
+				return err
+			}
+			if _, err := w.Write(bts); err != nil {
+				return err
+			}
+		}
+		return scanner.Err()
+	}
+}
\ No newline at end of file