Re: Spirit X3 employee.cpp compile error

On 08/31/2016 12:31 AM, Larry Evans wrote:
> On 08/20/2016 08:30 AM, Larry Evans wrote:
> [snip]
>
>> OOPS.  I should have re-looked at:
>>
>> https://github.com/boostorg/spirit/blob/develop/workbench/x3/toy/toy.cpp#L134
>>
>> which shows the rule_definition<>::parse function stores the
>> rule definition in the context dictionary.  Then, even
>> when BOOST_SPIRIT_DEFINE is not used, the rule rhs is looked up
>> by the rule<...>::parse function:
>>
>> https://github.com/boostorg/spirit/blob/develop/workbench/x3/toy/toy.cpp#L154
>>
>> The process is a little more complicated in the actual code.
>> There, rule_defintion<...>::parse:
>>
>> https://github.com/boostorg/spirit/blob/master/include/boost/spirit/home/x3/nonterminal/rule.hpp#L64
>>
>> *maybe* does something similar by putting the definition in the
>> context dictionary where the key is the rule ID.
> Yep, it's done here:
>
> https://github.com/boostorg/spirit/blob/master/include/boost/spirit/home/x3/nonterminal/detail/rule.hpp#L209
>
> in the expression:
>
>    make_rule_context<ID>(rhs, context, is_default_parse_rule())
>
> which, in case BOOST_SPIRIT_DEFINE is not used to define the rule,
> and the rule definition is not already in the context, calls:
>
> https://github.com/boostorg/spirit/blob/master/include/boost/spirit/home/x3/support/context.hpp#L89
>
> However, this only happens if rule_definition's on on the RHS of rules,
> as done here:
>
> http://coliru.stacked-crooked.com/a/41425cb30e49bc8a
>
> in lines 29-39 where process, node, and node_map are all rule_definition's.
>
> However, this use of rule_definitions on the RHS or rules suffers the
> same "crazy long mangled names" problem mentioned by Tongari here:
>
> http://boost.2283326.n4.nabble.com/compare-of-2-existing-methods-to-implement-grammar-recursion-tt4687574.html#a4687690


Another problem with this method is that mutually recursive rules
cannot be done for reasons mentioned in the //Result: comment of:

https://github.com/cppljevans/spirit/blob/trace-design/x3-design/employee_calc1_context_DEFINE.cpp

[snip]


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