Comments for Boost.Spirit

Comment on Creating Your Own Parser Component for Spirit.Qi by Leopold Talirz

Leopold Talirz — Wed, 25 Jan 2012 14:26:51 +0000

If someone is having problems compiling iter_pos.hpp – the file is not completely self-contained as claimed in the article. It will compile after adding

#include

(I am sure much less would be needed – I did not check).

Comment on Parsing a List of Key-Value Pairs Using Spirit.Qi by Łukasz

Łukasz — Sun, 22 Jan 2012 00:47:23 +0000

What if I wanted the container not be a map or vector, but MyContainer>? What interface should it expose or what traits do I need to specialize?

Comment on AST Construction with the Universal Tree by Olaf

Olaf — Wed, 14 Dec 2011 11:35:57 +0000

What is the current status of utree? Bryce Lelbach doesn’t continue to develop the example use case prana (https://github.com/brycelelbach/prana) any more, isn’t? I like his idea to register callbacks (but imo he overused shared_ptr). On the compiler tutorial there isn’t progress with utree also. Shall I use utree for new parsers or use the old AST approach?

Comment on Debugging by Mateusz Loskot

Mateusz Loskot — Fri, 09 Dec 2011 22:55:59 +0000

One clarification to Rob’s last suggestion. The macro should be placed after rule assignment, not before:

grammar() : grammar::base_type(rule)
{
rule = …;

BOOST_SPIRIT_DEBUG_NODE(rule);
}

Comment on The Magical Power of Attributes in Spirit – Operators by Krzyszof

Krzyszof — Sun, 27 Nov 2011 10:35:07 +0000

Rules for attributes of compound components are nicely documented in “Compound Attribute Rules” but what about components combined with operator ()? It is “obvoius” that attribite of () is same as attribute of internal components?

I assume:
1) a: A, b: A, c: A –> a >> ( b > c ): vector
2) a: A, b: B, c: C –> a >> ( b > c ): tuple >

Is there some (easy?) way to force case 2 to behave like:
3) a: A, b: B, c: C –> a >> ( b > c ): tuple
Of course removing brackets is not an option.

Comment on The Keyword parser by Krzyszof

Krzyszof — Sat, 26 Nov 2011 23:59:40 +0000

I wonder how kwd and operator “/” can be combined with “>>”.

Suppose one wants to parse:
item “name1″ ( x 1 y 2 )
item “name2″ ( y 3 x 4 )

Should it be something like:
item_rule %= lit(“item”) >> parse_name >> ‘(‘ >> kwd(“x”)[int_] / kwd(“y”)[int_] >> ‘)’;

this fails for me. Adding brackets does not help.

Comment on Build a Compiler, What to Build? by Austin

Austin — Thu, 10 Nov 2011 02:44:14 +0000

URL for SPECS?

Comment on Build a Compiler, What to Build? by Matthew

Matthew — Tue, 08 Nov 2011 21:07:44 +0000

I would love to see a SPECS compiler. I recently discovered the syntax, and while I think some things need to be changed–mostly to take advantage of C++11 features, which I think could be expressed better by a syntax independent of C–it’s refreshing to see a syntactical re-imagining of C++ that doesn’t try to add the sorts of language features that slow down runtime and defeats the whole purpose of using C++.

Comment on Parsing Arbitrary Things in Any Sequence by Jamboree

Jamboree — Tue, 20 Sep 2011 08:25:43 +0000

Sorry for the late reply,

It’s used when you want all the elements to be matched exactly once, e.g.

Using: strict[char_('a') ^ 'b' ^ 'c']
Input: cab -> success
Input: ca -> fail

You can access the code at https://github.com/jamboree/boost-jamboree-spirit

Yet, I feel the usage of permutation (strict or not) is limited, it can’t deal with the case in which the elements are required to be delimited…

Comment on Parsing a List of Key-Value Pairs Using Spirit.Qi by Jurek

Jurek — Wed, 07 Sep 2011 18:38:40 +0000

Thank you for this example.

I have modified it to parse lines of key-value pairs. I simply added ‘>> qi::eol’ to the query rule, and created a rule ‘start = +query’. I use std::vector< std::map > to store the parsed data. Is it possible to make a parser that put these pairs into `std::vector< boost::shared_ptr`?