From 49241e7a8ca8284b56857bee2ffaf31eda1f0b55 Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Tue, 7 Apr 2020 18:27:20 +1200
Subject: [PATCH] node: preserve comments

---
 README.md               |  2 +-
 fixtures/0001.php       |  1 +
 fixtures/0002-loops.php |  2 +-
 main.go                 |  3 +++
 node.go                 | 46 ++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index a8cbb2c..b88acf6 100644
--- a/README.md
+++ b/README.md
@@ -76,7 +76,7 @@ The goal is to produce idiomatic, maintainable Go code as part of a one-off conv
 		- [ ] PHPUnit -> Go Test
 		- [ ] Replace Composer/PSR-4 autoloading with Go imports
 [X] Variadic function parameters
-[ ] Preserve comments
+[X] Preserve comments
 [ ] Preserve rough line spacing
 [ ] Convert wordpress / mediawiki / symfony
 	- [ ] Option to convert with preset=cli, preset=web, webroot path
diff --git a/fixtures/0001.php b/fixtures/0001.php
index 568f738..0971029 100644
--- a/fixtures/0001.php
+++ b/fixtures/0001.php
@@ -14,6 +14,7 @@ class Bar {
 	}
 	
 	function scalarThrower() {
+		// Comment
 		throw "str";
 	}
 }
diff --git a/fixtures/0002-loops.php b/fixtures/0002-loops.php
index 998acea..6588216 100644
--- a/fixtures/0002-loops.php
+++ b/fixtures/0002-loops.php
@@ -9,7 +9,7 @@ for($i = 0; $i < 3; ++$i) {
 	foreach($foo2 as $v2) {
 	}
 	
-	while(true) {
+	while(true /* infinite. */) {
 	}
 	
 	do {		
diff --git a/main.go b/main.go
index 61c5d6a..034654e 100644
--- a/main.go
+++ b/main.go
@@ -28,6 +28,9 @@ func ConvertFile(filename string) (string, error) {
 		panic(err)
 	}
 
+	// Enable comments extraction
+	p.WithFreeFloating()
+
 	p.Parse()
 	for _, err := range p.GetErrors() {
 		return "", errors.New(err.String())
diff --git a/node.go b/node.go
index 43dba3d..6db7e2a 100644
--- a/node.go
+++ b/node.go
@@ -8,6 +8,7 @@ import (
 	//"strconv"
 	"strings"
 
+	"github.com/z7zmey/php-parser/freefloating"
 	"github.com/z7zmey/php-parser/node"
 	"github.com/z7zmey/php-parser/node/expr"
 	"github.com/z7zmey/php-parser/node/expr/assign"
@@ -43,7 +44,50 @@ type conversionState struct {
 
 //
 
-func (this *conversionState) convert(n_ node.Node) (string, error) {
+func (this *conversionState) convert(n node.Node) (string, error) {
+
+	// Get any whitespace/comments attached to this node
+	freePrefix := ""
+	freeSuffix := ""
+
+	if ff := n.GetFreeFloating(); ff != nil && !ff.IsEmpty() {
+		for positionType, elements := range *ff {
+		element:
+			for _, element := range elements {
+				if element.StringType == freefloating.TokenType {
+					// Skip <?php
+					continue element
+				}
+				if element.StringType == freefloating.WhiteSpaceType {
+					// We can't insert arbitrary whitespace
+					// TODO the number of newlines would be fine ONLY IF this is a *stmt
+					continue element
+				}
+
+				switch positionType {
+				default:
+					fallthrough
+				case freefloating.Start:
+					freePrefix += element.Value
+
+				case freefloating.End, freefloating.AltEnd:
+					freeSuffix += element.Value
+				}
+			}
+		}
+	}
+
+	// Convert the node itself
+	ret, err := this.convertNoFreeFloating(n)
+	if err != nil {
+		return "", err
+	}
+
+	return freePrefix + ret + freeSuffix, nil
+}
+
+func (this *conversionState) convertNoFreeFloating(n_ node.Node) (string, error) {
+
 	switch n := n_.(type) {
 
 	//