handle left-contained expressions Expressions that don't need parentheses when there is a unary operator to their left. For example, yield expressions: if (!yield x ()) ...

Changes

2 changed files (+29/-8)

• grammar.js
  • @@ -103,6 +103,17 @@ $.typeof_expression,
    $.postfix_expression, ), + // expressions that are contained by an operator to the left + // for example: + // if (!yield x()) + // ^^^^^^^^^ -- we don't need parens here because of the '!' operator + _left_contained_expression: $ => choice( + $._contained_expression, + $.yield_expression, + $.static_cast_expression, + $._unary_expression + ), + member_access_expression: $ => seq( optional(seq( $._contained_expression,
  • @@ -161,12 +172,12 @@ postfix_expression: $ => prec.left(15, seq($._expression, choice('++', '--'))),
    static_cast_expression: $ => prec.right(14, seq('(', choice($.type, '!', 'owned'), ')', $._expression)), typeof_expression: $ => prec.right(14, seq('typeof', '(', $.type, ')')), sizeof_expression: $ => prec.right(14, seq('sizeof', '(', $.type, ')')), - dereferencing_expression: $ => prec.right(14, seq('*', $._contained_expression)), - addressof_expression: $ => prec.right(14, seq('&', $._contained_expression)), - arithmetic_negation_expression: $ => prec.right(14, seq('-', $._contained_expression)), - prefix_expression: $ => prec.right(14, seq(choice('++', '--'), $._contained_expression)), - bitwise_negation_expression: $ => prec.right(14, seq('~', $._contained_expression)), - logical_negation_expression: $ => prec.right(14, seq(choice('!', 'not'), $._contained_expression)), + dereferencing_expression: $ => prec.right(14, seq('*', $._left_contained_expression)), + addressof_expression: $ => prec.right(14, seq('&', $._left_contained_expression)), + arithmetic_negation_expression: $ => prec.right(14, seq('-', $._left_contained_expression)), + prefix_expression: $ => prec.right(14, seq(choice('++', '--'), $._left_contained_expression)), + bitwise_negation_expression: $ => prec.right(14, seq('~', $._left_contained_expression)), + logical_negation_expression: $ => prec.right(14, seq(choice('!', 'not'), $._left_contained_expression)), _unary_expression: $ => prec.right(14, choice( $.dereferencing_expression, $.addressof_expression,
  • @@ -881,7 +892,8 @@ [$._contained_expression, $.method_call_expression], // for ambiguity because of contained expressions
    [$._expression, $.element_access_expression], // because EAEs have a prefix that is a member access [$.element_access_expression], // for ambiguity because of contained expressions [$.initializer, $.block], // because {} is ambiguous in statement-expression contexts - [$.if_statement] // because of ambiguity with nested if statements + [$.if_statement], // because of ambiguity with nested if statements + [$._expression, $._left_contained_expression] ], extras: $ => [
• test/corpus/expressions.txt
  • @@ -8,6 +8,8 @@ a in b();
    3 = 3; x.y.z(); (3 + 1).to_string(); + if (!yield x()) { + } } ---
  • @@ -43,4 +45,11 @@ (member_access_expression
    (arithmetic_expression (literal (integer)) (literal (integer))) - (identifier)))))))) + (identifier)))) + (if_statement + (logical_negation_expression + (yield_expression + (method_call_expression + (member_access_expression + (identifier))))) + (block))))))