initial commit

Initial gxpath project.

.gitignore

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+# vscode
+.vscode
+debug
+*.test
+
+./build
+
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof

LICENSE

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+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

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+gxpath
+====
+gxpath is a XPath 2.0 Go packages, that lets you extract data from the custom documents using XPath expression.
+
+**[XQuery](https://github.com/antchfx/xquery)** : gxpath implementation, lets you extract data from HTML/XML documents using XPath.
+
+Features
+====
+1. Standard path expression and axis name path.
+
+2. Numeric functions and logical operator.. (+,-,div,mod,=,>,<,>=,<=,!=)
+
+3. Boolean operator. (or,and)
+
+4. Supported build-in functions.
+    - position()
+    - last()
+    - count()
+    - coming more
+
+Examples
+====
+[main.go](http://github.com/antchfx/gxpath/example) : you can test XPath expr supported. 

example/README.md

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+test xml document
+====
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<bookstore>
+<book>
+  <title lang="en" id="1">Harry Potter</title>
+  <price>29.99</price>
+</book>
+<book>
+  <title lang="en" id="2">Learning XML</title>
+  <price>39.95</price>
+</book>
+</bookstore>
+```
+
+How to run test example
+===
+1. go run main.go
+
+2. enter your XPath expression.(etc,//book,//@lang,//book[price>20])

example/main.go

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+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/antchfx/gxpath"
+	"github.com/antchfx/gxpath/xpath"
+	"github.com/antchfx/xml"
+)
+
+type xmlNodeNavigator struct {
+	doc      *xml.Node
+	currnode *xml.Node
+	attindex int
+}
+
+func (n *xmlNodeNavigator) LocalName() string {
+	if n.attindex != -1 && len(n.currnode.Attr) > 0 {
+		return n.currnode.Attr[n.attindex].Name.Local
+	} else {
+		return n.currnode.Data
+	}
+}
+
+func (n *xmlNodeNavigator) Current() xpath.Node {
+	return n.currnode
+}
+
+func (n *xmlNodeNavigator) Value() string {
+	switch n.currnode.Type {
+	case xml.CommentNode:
+		return n.currnode.Data
+	case xml.DocumentNode:
+		return ""
+	case xml.ElementNode:
+		if n.attindex != -1 {
+			return n.currnode.Attr[n.attindex].Value
+		}
+		return XmlNodeInnerText(n.currnode)
+	case xml.TextNode:
+		return n.currnode.Data
+	default:
+		panic(fmt.Sprintf("unknowed XmlNodeType: %v", n.currnode.Type))
+	}
+}
+
+func (n *xmlNodeNavigator) Prefix() string {
+	return ""
+}
+
+func (n *xmlNodeNavigator) NodeType() xpath.NodeType {
+	switch n.currnode.Type {
+	case xml.CommentNode:
+		return xpath.CommentNode
+	case xml.TextNode:
+		return xpath.TextNode
+	case xml.DeclarationNode, xml.DocumentNode:
+		return xpath.RootNode
+	case xml.ElementNode:
+		if n.attindex != -1 {
+			return xpath.AttributeNode
+		}
+		return xpath.ElementNode
+	default:
+		panic(fmt.Sprintf("unknowed XmlNodeType: %v", n.currnode.Type))
+	}
+}
+
+func (n *xmlNodeNavigator) Copy() xpath.NodeNavigator {
+	nav := *n
+	return &nav
+}
+
+func (n *xmlNodeNavigator) MoveTo(other xpath.NodeNavigator) bool {
+	nav, ok := other.(*xmlNodeNavigator)
+	if !ok {
+		return false
+	}
+	if nav.doc == n.doc {
+		n.currnode = nav.currnode
+		n.attindex = nav.attindex
+		return true
+	}
+	return false
+}
+
+func (n *xmlNodeNavigator) MoveToRoot() {
+	n.currnode = n.doc
+}
+
+func (n *xmlNodeNavigator) MoveToPrevious() bool {
+	if n.currnode.PrevSibling == nil {
+		return false
+	}
+	n.currnode = n.currnode.PrevSibling
+	return true
+}
+
+func (n *xmlNodeNavigator) MoveToParent() bool {
+	if n.currnode.Parent == nil {
+		return false
+	}
+	n.currnode = n.currnode.Parent
+	return true
+}
+
+func (n *xmlNodeNavigator) MoveToFirst() bool {
+	if n.currnode.PrevSibling == nil {
+		return false
+	}
+	for n.currnode.PrevSibling != nil {
+		n.currnode = n.currnode.PrevSibling
+	}
+	return true
+}
+
+func (n *xmlNodeNavigator) String() string {
+	return n.Value()
+}
+
+func (n *xmlNodeNavigator) MoveToNext() bool {
+	if cur := n.currnode.NextSibling; cur == nil {
+		return false
+	} else {
+		n.currnode = cur
+	}
+	return true
+}
+
+func (n *xmlNodeNavigator) MoveToFirstAttribute() bool {
+	if len(n.currnode.Attr) == 0 {
+		return false
+	}
+	n.attindex = 0
+	return true
+}
+
+func (n *xmlNodeNavigator) MoveToNextAttribute() bool {
+	if n.attindex >= len(n.currnode.Attr)-1 {
+		return false
+	}
+	n.attindex++
+	return true
+}
+
+func (n *xmlNodeNavigator) MoveToChild() bool {
+	if cur := n.currnode.FirstChild; cur == nil {
+		return false
+	} else {
+		n.currnode = cur
+	}
+	return true
+}
+
+func XmlNodeInnerText(n *xml.Node) string {
+	var b bytes.Buffer
+	var output func(*xml.Node)
+	output = func(node *xml.Node) {
+		if node.Type == xml.TextNode {
+			b.WriteString(node.Data)
+		}
+		for child := node.FirstChild; child != nil; child = child.NextSibling {
+			output(child)
+		}
+	}
+	output(n)
+	return b.String()
+}
+
+func main() {
+	s := `<?xml version="1.0" encoding="UTF-8"?>
+<bookstore>
+<book>
+  <title lang="en" id="1">Harry Potter</title>
+  <price>29.99</price>
+</book>
+<book>
+  <title lang="en" id="2">Learning XML</title>
+  <price>39.95</price>
+</book>
+</bookstore>
+`
+	root, err := xml.Parse(strings.NewReader(s))
+	if err != nil {
+		panic(err)
+	}
+	nav := &xmlNodeNavigator{doc: root, currnode: root, attindex: -1}
+	fmt.Println("enter XPath express and press enter key to test.")
+	scan := bufio.NewScanner(os.Stdin)
+	for {
+		scan.Scan()
+		iter, err := gxpath.Select(nav, strings.TrimSpace(scan.Text()))
+		if err != nil {
+			fmt.Println(fmt.Sprintf("got error: %v", err))
+		} else {
+			for iter.MoveNext() {
+				fmt.Println(">>")
+				fmt.Println(iter.Current().Value())
+			}
+		}
+		fmt.Println("==========")
+	}
+}