php-parser/README.md

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<!--
Title: PHP Parser
Description: A Parser for PHP written in Go.
Author: Slizov Vadim
Keywords: go golang php php-parser ast
-->
<img src="./parser.jpg" alt="PHP Parser written in Go" width="980"/>
[![Go Report Card](https://goreportcard.com/badge/github.com/z7zmey/php-parser)](https://goreportcard.com/report/github.com/z7zmey/php-parser)
[![Exago](https://api.exago.io:443/badge/tests/github.com/z7zmey/php-parser)](https://exago.io/project/github.com/z7zmey/php-parser)
[![Exago](https://api.exago.io:443/badge/cov/github.com/z7zmey/php-parser)](https://exago.io/project/github.com/z7zmey/php-parser)
[![GoDoc](https://godoc.org/github.com/z7zmey/php-parser?status.svg)](https://godoc.org/github.com/z7zmey/php-parser)
#### Try it online: [demo](https://php-parser.com)
## Features:
- Fully support PHP 5 and PHP 7 syntax
- Abstract syntax tree (AST) representation
- Traversing AST
- Namespace resolver
- Able to parse syntax-invalid PHP files
## Roadmap
- Control Flow Graph (CFG)
- PhpDocComment parser
- Stabilize api
## Install
```
go get github.com/z7zmey/php-parser
```
## CLI
```
php-parser [-php5] <path> ...
```
Dump AST to stdout.
## Example
```Golang
package main
import (
"fmt"
"bytes"
"os"
"github.com/z7zmey/php-parser/php7"
"github.com/z7zmey/php-parser/visitor"
)
func main() {
src := bytes.NewBufferString(`<? echo "Hello world";`)
parser := php7.NewParser(src, "example.php")
parser.Parse()
for _, e := range parser.GetErrors() {
fmt.Println(e)
}
visitor := visitor.Dumper{
Writer: os.Stdout,
Indent: "",
Comments: parser.GetComments(),
Positions: parser.GetPositions(),
}
rootNode := parser.GetRootNode()
rootNode.Walk(visitor)
}
```
## Namespace resolver
Namespace resolver is a visitor that resolves nodes fully qualified name and saves into `map[node.Node]string` structure
- For `Class`, `Interface`, `Trait`, `Function`, `Constant` nodes it saves name with current namespace.
- For `Name`, `Relative`, `FullyQualified` nodes it resolves `use` aliases and saves a fully qualified name.
## Parsing syntax-invalid PHP files
If we try to parse `$a$b;` then the parser triggers error 'syntax error: unexpected T_VARIABLE'. Token `$b` is unexpected, but parser recovers parsing process and returns `$b;` statement to AST, because it is syntactically correct.
## Pretty printer
```Golang
nodes := &stmt.StmtList{
Stmts: []node.Node{
&stmt.Namespace{
NamespaceName: &name.Name{Parts: []node.Node{&name.NamePart{Value: "Foo"}}},
},
&stmt.Class{
Modifiers: []node.Node{&node.Identifier{Value: "abstract"}},
ClassName: &name.Name{Parts: []node.Node{&name.NamePart{Value: "Bar"}}},
Extends: &stmt.ClassExtends{
ClassName: &name.Name{Parts: []node.Node{&name.NamePart{Value: "Baz"}}},
},
Stmts: []node.Node{
&stmt.ClassMethod{
Modifiers: []node.Node{&node.Identifier{Value: "public"}},
MethodName: &node.Identifier{Value: "greet"},
Stmt: &stmt.StmtList{
Stmts: []node.Node{
&stmt.Echo{
Exprs: []node.Node{
&scalar.String{Value: "'Hello world'"},
},
},
},
},
},
},
},
},
}
file := os.Stdout
p := printer.NewPrinter(file, " ")
p.PrintFile(nodes)
```
Output:
```PHP
<?php
namespace Foo;
abstract class Bar extends Baz
{
public function greet()
{
echo 'Hello world';
}
}
```