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;
$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: Stmt_Expression(
        expr: Expr_Assign(
            var: Expr_Variable(
                name: a
                comments: array(
                    0: // simple assign
                )
            )
            expr: Expr_Variable(
                name: b
            )
            comments: array(
                0: // simple assign
            )
        )
        comments: array(
            0: // simple assign
        )
    )
    1: Stmt_Expression(
        expr: Expr_AssignOp_BitwiseAnd(
            var: Expr_Variable(
                name: a
                comments: array(
                    0: // combined assign
                )
            )
            expr: Expr_Variable(
                name: b
            )
            comments: array(
                0: // combined assign
            )
        )
        comments: array(
            0: // combined assign
        )
    )
    2: Stmt_Expression(
        expr: Expr_AssignOp_BitwiseOr(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    3: Stmt_Expression(
        expr: Expr_AssignOp_BitwiseXor(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    4: Stmt_Expression(
        expr: Expr_AssignOp_Concat(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    5: Stmt_Expression(
        expr: Expr_AssignOp_Div(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    6: Stmt_Expression(
        expr: Expr_AssignOp_Minus(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    7: Stmt_Expression(
        expr: Expr_AssignOp_Mod(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    8: Stmt_Expression(
        expr: Expr_AssignOp_Mul(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    9: Stmt_Expression(
        expr: Expr_AssignOp_Plus(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    10: Stmt_Expression(
        expr: Expr_AssignOp_ShiftLeft(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    11: Stmt_Expression(
        expr: Expr_AssignOp_ShiftRight(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    12: Stmt_Expression(
        expr: Expr_AssignOp_Pow(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    13: Stmt_Expression(
        expr: Expr_AssignOp_Coalesce(
            var: Expr_Variable(
                name: a
            )
            expr: Expr_Variable(
                name: b
            )
        )
    )
    14: Stmt_Expression(
        expr: 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
            )
        )
        comments: array(
            0: // chained assign
        )
    )
    15: Stmt_Expression(
        expr: Expr_AssignRef(
            var: Expr_Variable(
                name: a
                comments: array(
                    0: // by ref assign
                )
            )
            expr: Expr_Variable(
                name: b
            )
            comments: array(
                0: // by ref assign
            )
        )
        comments: array(
            0: // by ref assign
        )
    )
    16: Stmt_Expression(
        expr: 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
            )
        )
        comments: array(
            0: // list() assign
        )
    )
    17: Stmt_Expression(
        expr: 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
            )
        )
    )
    18: Stmt_Expression(
        expr: 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
            )
        )
    )
    19: Stmt_Expression(
        expr: Expr_PreInc(
            var: Expr_Variable(
                name: a
            )
            comments: array(
                0: // inc/dec
            )
        )
        comments: array(
            0: // inc/dec
        )
    )
    20: Stmt_Expression(
        expr: Expr_PostInc(
            var: Expr_Variable(
                name: a
            )
        )
    )
    21: Stmt_Expression(
        expr: Expr_PreDec(
            var: Expr_Variable(
                name: a
            )
        )
    )
    22: Stmt_Expression(
        expr: Expr_PostDec(
            var: Expr_Variable(
                name: a
            )
        )
    )
)