JMESPath let expression with operator in variable binding

[BartelNieuwenhuyse]

JMESPath expressions with an operator in the expression part of a variable binding (expression between 'let $var=' and 'in') are not parsed correctly.

given:
{"foo": false, "bar": true}

search expression:
let $var = foo || bar in $var

expected:
yields result true

actual:
gives error during evaluation: assertion 'stack.size() == 1' failed

Include a small, self-contained example if possible

TEST_CASE("jmespath let with operator binding expression")
{
    SECTION("Test binary or operator")
    {
        auto doc = jsoncons::json::parse(R"({"foo": false, "bar": true})");
        auto expected = jsoncons::json::parse(R"(true)");

        std::string query = R"(let $op = foo || bar in $op)";
        auto expr = jmespath::make_expression<jsoncons::json>(query);

        jsoncons::json result = expr.evaluate(doc);
        CHECK(expected == result);
    }
}

[danielaparker]

Thanks! I'm guessing there's an issue with the handling of expr_state::expect_in_or_comma. Will need to be investigated.

[BartelNieuwenhuyse]

I can 'work around' it using parenthesis:

search expression:
let $var = (foo || bar) in $var

gives the expected result.

I'll have a look at the parenthesis logic '(' ... ')' and see if I can make a fix that applies the same logic to '=' ... 'in'

[BartelNieuwenhuyse]

Thank you for merging the related pull request #691, but you @danielaparker stated "expression_context serves no other purpose, and can be removed." Is removing expression_context something that will done, or should I open a new pull request for it?

[danielaparker]

Feel free to submit a PR to remove it.

[BartelNieuwenhuyse]

PR #693