lib/strings: merge lib/parser here

The first idea of parser is to provide generic parser for both bytes and
string.
After we introduce lib/parser there is not much changes to that package.
Also, since we create another Parser in lib/bytes that accept and
return token as []byte, the lib/parser is not unique anymore.

The following function/methods changes to minimize conflict in the future,

  * Lines become LinesOfFile
  * New become NewParser
  * Open become OpenForParser
  * Token become Read
  * TokenEscaped become ReadEscaped
  * TokenTrimSpace become ReadNoSpace

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/strings/parser_example_test.go b/lib/strings/parser_example_test.go
new file mode 100644
index 00000000..726609cb
--- /dev/null
+++ b/lib/strings/parser_example_test.go
@@ -0,0 +1,53 @@
+// Copyright 2019, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package strings
+
+import (
+	"fmt"
+	"strings"
+)
+
+func ExampleNewParser() {
+	content := "[test]\nkey = value"
+	p := NewParser(content, `=[]`)
+
+	for {
+		token, del := p.Read()
+		token = strings.TrimSpace(token)
+		fmt.Printf("%q %q\n", token, del)
+		if del == 0 {
+			break
+		}
+	}
+	// Output:
+	// "" '['
+	// "test" ']'
+	// "key" '='
+	// "value" '\x00'
+}
+
+func ExampleParser_ReadNoSpace() {
+	var (
+		content = " 1 , \r\t\f, 2 , 3 , 4 , "
+		p       = NewParser(content, `,`)
+
+		tok string
+		r   rune
+	)
+	for {
+		tok, r = p.ReadNoSpace()
+		fmt.Printf("%q\n", tok)
+		if r == 0 {
+			break
+		}
+	}
+	// Output:
+	// "1"
+	// ""
+	// "2"
+	// "3"
+	// "4"
+	// ""
+}