Curlies around variable names in encapsulated strings are mishandled

[jj101k]

"use strict";
var engine = require('php-parser');
var parser = new engine({});
var AST1 = parser.parseEval('echo "Hello ${world}";');
console.log(AST1.children[0].arguments[0].value[1]);
var AST2 = parser.parseEval('echo "Hello " . ${world};');
console.log(AST2.children[0].arguments[0].right);

Output is:

Variable {
  kind: 'variable',
  name: Variable { kind: 'variable', name: 'orld', byref: false },
  byref: false }
Variable {
  kind: 'variable',
  name: 
   ConstRef {
     kind: 'constref',
     name: Identifier { kind: 'identifier', resolution: 'uqn', name: 'world' } },
  byref: false }

The two items should be the same. Presumably php-parser is treating it like an explicit interpolated expression (eg. {$world}) by skipping the first character.

[ichiriac]

Thanks @jj101k for reporting this issue. You're totally right, I've didn't saw it.

The PHP might interpret as this (did not dig enough) :

Variable {
  kind: 'variable',
  name: String{ kind: 'string', name: 'world' },
  byref: false }

BUT, this is a special case in PHP, because the real syntax should be :

Variable {
  kind: 'variable',
  name: 
   ConstRef {
     kind: 'constref',
     name: Identifier { kind: 'identifier', resolution: 'uqn', name: 'world' } },
  byref: false }

Because the syntax is ${expr} where the variable name is resolved by the expression. Here world is considered as a constant, and if it's not defined, PHP is using its name as contents, so resolves it as $world. But as the constant is not defined, if PHP follows strictly these would result in notices errors as the constant is not defined.

I'm saying this because of this behavior :

$> php -r "define(\"world\", \"foo\"); \$foo = \"foobar\"; echo \"hello \${ world }\";"
>> hello foobar

See the extra white spaces around world

$> php -r "define(\"world\", \"foo\"); \$foo = \"foobar\"; echo \"hello \${world}\";"
>> PHP Notice:  Undefined variable: world in Command line code on line 1
>> PHP Stack trace:
>> PHP   1. {main}() Command line code:0
>> hello

Here world is not resolved as a constant but as directly the variable name. The tokens from lexer may also differ :

${world} gives : T_DOLLAR_OPEN_CURLY_BRACES"${" T_STRING_VARNAME"world" "}"
${ world } gives : T_DOLLAR_OPEN_CURLY_BRACES"${" T_WHITESPACE" " T_STRING"world" T_WHITESPACE" " "}"

---

BUT, as usual in PHP internal, it's not that easy, because the T_STRING_VARNAME is only true with encapsed string. Here the behavior outside an string :

$> php -r "echo \${ world };"
PHP Notice:  Use of undefined constant world - assumed 'world' in Command line code on line 1
PHP Stack trace:
PHP   1. {main}() Command line code:0
PHP Notice:  Undefined variable: world in Command line code on line 1
PHP Stack trace:
PHP   1. {main}() Command line code:0

And the result without extra spaces around world :

$> php -r "echo \${world};"
PHP Notice:  Use of undefined constant world - assumed 'world' in Command line code on line 1
PHP Stack trace:
PHP   1. {main}() Command line code:0
PHP Notice:  Undefined variable: world in Command line code on line 1
PHP Stack trace:
PHP   1. {main}() Command line code:0

So, to conclude, you're right I've got multiple bugs on this, but no, "${world}" is not the same as ${world} because it's encapsulated into a string and treated differently, but "${ world }" should be the same as ${world}

---

Expected output :

"${world}" is the same as "${\"world\"}"

{ kind: 'variable', name: { kind: 'string', value: 'world' } ...

"${ world }" is the same as ${world}

{ kind: 'variable', name: { kind: 'constref', name: { kind: 'identifier', name: 'world' } ...

[ichiriac]

The ouput is now corrected. The first char is no more stripped. The behavior is the same as PHP.

---

PHP Script :

<?php
echo "Hello ${world}";
echo "Hello $world";
echo "Hello ${ world }";
echo "Hello " . ${world};

AST Structure :

{
  "kind": "program",
  "children": [
    {
      "kind": "echo",
      "arguments": [
        {
          "kind": "encapsed",
          "value": [
            {
              "kind": "string",
              "value": "Hello ",
              "isDoubleQuote": false
            },
            {
              "kind": "variable",
              "name": {
                "kind": "variable",
                "name": "world",
                "byref": false
              },
              "byref": false
            }
          ],
          "type": "string"
        }
      ]
    },
    {
      "kind": "echo",
      "arguments": [
        {
          "kind": "encapsed",
          "value": [
            {
              "kind": "string",
              "value": "Hello ",
              "isDoubleQuote": false
            },
            {
              "kind": "variable",
              "name": "world",
              "byref": false
            }
          ],
          "type": "string"
        }
      ]
    },
    {
      "kind": "echo",
      "arguments": [
        {
          "kind": "encapsed",
          "value": [
            {
              "kind": "string",
              "value": "Hello ",
              "isDoubleQuote": false
            },
            {
              "kind": "variable",
              "name": {
                "kind": "constref",
                "name": {
                  "kind": "identifier",
                  "resolution": "uqn",
                  "name": "world"
                }
              },
              "byref": false
            }
          ],
          "type": "string"
        }
      ]
    },
    {
      "kind": "echo",
      "arguments": [
        {
          "kind": "bin",
          "type": ".",
          "left": {
            "kind": "string",
            "value": "Hello ",
            "isDoubleQuote": true
          },
          "right": {
            "kind": "variable",
            "name": {
              "kind": "constref",
              "name": {
                "kind": "identifier",
                "resolution": "uqn",
                "name": "world"
              }
            },
            "byref": false
          }
        }
      ]
    }
  ],
  "errors": []
}