Assignments
-----
<?php
// simple assign
$a = $b;

// combined assign
$a &= $b;
$a |= $b;
$a ^= $b;
$a .= $b;
$a /= $b;
$a -= $b;
$a %= $b;
$a *= $b;
$a += $b;
$a <<= $b;
$a >>= $b;
$a **= $b;

// chained assign
$a = $b *= $c **= $d;

// by ref assign
$a =& $b;

// list() assign
list($a) = $b;
list($a, , $b) = $c;
list($a, list(, $c), $d) = $e;

// inc/dec
++$a;
$a++;
--$a;
$a--;
-----
array(
    0: Expr_Assign(
        var: Expr_Variable(
            name: a
            comments: array(
                0: // simple assign
            )
        )
        expr: Expr_Variable(
            name: b
        )
        comments: array(
            0: // simple assign
        )
    )
    1: Expr_AssignOp_BitwiseAnd(
        var: Expr_Variable(
            name: a
            comments: array(
                0: // combined assign
            )
        )
        expr: Expr_Variable(
            name: b
        )
        comments: array(
            0: // combined assign
        )
    )
    2: Expr_AssignOp_BitwiseOr(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    3: Expr_AssignOp_BitwiseXor(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    4: Expr_AssignOp_Concat(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    5: Expr_AssignOp_Div(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    6: Expr_AssignOp_Minus(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    7: Expr_AssignOp_Mod(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    8: Expr_AssignOp_Mul(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    9: Expr_AssignOp_Plus(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    10: Expr_AssignOp_ShiftLeft(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    11: Expr_AssignOp_ShiftRight(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    12: Expr_AssignOp_Pow(
        var: Expr_Variable(
            name: a
        )
        expr: Expr_Variable(
            name: b
        )
    )
    13: Expr_Assign(
        var: Expr_Variable(
            name: a
            comments: array(
                0: // chained assign
            )
        )
        expr: Expr_AssignOp_Mul(
            var: Expr_Variable(
                name: b
            )
            expr: Expr_AssignOp_Pow(
                var: Expr_Variable(
                    name: c
                )
                expr: Expr_Variable(
                    name: d
                )
            )
        )
        comments: array(
            0: // chained assign
        )
    )
    14: Expr_AssignRef(
        var: Expr_Variable(
            name: a
            comments: array(
                0: // by ref assign
            )
        )
        expr: Expr_Variable(
            name: b
        )
        comments: array(
            0: // by ref assign
        )
    )
    15: Expr_Assign(
        var: Expr_List(
            items: array(
                0: Expr_ArrayItem(
                    key: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                )
            )
            comments: array(
                0: // list() assign
            )
        )
        expr: Expr_Variable(
            name: b
        )
        comments: array(
            0: // list() assign
        )
    )
    16: Expr_Assign(
        var: Expr_List(
            items: array(
                0: Expr_ArrayItem(
                    key: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                )
                1: null
                2: Expr_ArrayItem(
                    key: null
                    value: Expr_Variable(
                        name: b
                    )
                    byRef: false
                )
            )
        )
        expr: Expr_Variable(
            name: c
        )
    )
    17: Expr_Assign(
        var: Expr_List(
            items: array(
                0: Expr_ArrayItem(
                    key: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                )
                1: Expr_ArrayItem(
                    key: null
                    value: Expr_List(
                        items: array(
                            0: null
                            1: Expr_ArrayItem(
                                key: null
                                value: Expr_Variable(
                                    name: c
                                )
                                byRef: false
                            )
                        )
                    )
                    byRef: false
                )
                2: Expr_ArrayItem(
                    key: null
                    value: Expr_Variable(
                        name: d
                    )
                    byRef: false
                )
            )
        )
        expr: Expr_Variable(
            name: e
        )
    )
    18: Expr_PreInc(
        var: Expr_Variable(
            name: a
        )
        comments: array(
            0: // inc/dec
        )
    )
    19: Expr_PostInc(
        var: Expr_Variable(
            name: a
        )
    )
    20: Expr_PreDec(
        var: Expr_Variable(
            name: a
        )
    )
    21: Expr_PostDec(
        var: Expr_Variable(
            name: a
        )
    )
)