Stream buffer

buffer/stream.go

@@ -0,0 +1,37 @@
+package buffer
+
+import (
+	"bytes"
+	"io"
+	"unicode/utf8"
+)
+
+type (
+	StreamBuffer struct {
+		input io.Reader
+	}
+)
+
+func NewStreamBuffer(input io.Reader) *StreamBuffer {
+	return &StreamBuffer{
+		input: input,
+	}
+}
+
+func (b *StreamBuffer) Next() rune {
+	var (
+		buf bytes.Buffer
+	)
+	for {
+		rbuf := make([]byte, 1)
+		if n, err := b.input.Read(rbuf); n != 1 || err != nil {
+			return 0
+		}
+		buf.Write(rbuf)
+		if ok := utf8.FullRune(buf.Bytes()); ok {
+			r, _ := utf8.DecodeRune(buf.Bytes())
+			return r
+		}
+	}
+	return 0
+}

parser/parser.go

@@ -20,8 +20,7 @@ type (
 )
 
 // Creates a new parser
-func New(b []byte, sels []string) *Parser {
-	buf := buffer.NewDataBuffer(b)
+func New(buf buffer.Bufferer, sels []string) *Parser {
 	return &Parser{
 		lex: lexer.New(buf),
 		ctx: &context{

run.go

@@ -1,18 +1,19 @@
 package main
 
 import (
-	"io/ioutil"
 	"os"
 
 	"github.com/kr/pretty"
+	"github.com/localhots/punk/buffer"
 	"github.com/localhots/punk/parser"
 )
 
 func main() {
 	f, _ := os.Open("test.json")
-	b, _ := ioutil.ReadAll(f)
+	// b, _ := ioutil.ReadAll(f)
+	buf := buffer.NewStreamBuffer(f)
 
-	p := parser.New(b, []string{
+	p := parser.New(buf, []string{
 		"/prices/*",
 		"/bananas/[*]/weight",
 	})