Boost.Phoenix is a C++ library to enable function programming in C++.
Questions tagged [boost-phoenix]
159 questions
3
votes
1 answer
boost::spirit semantic action: emit result
I am trying to learn boost::spirit to parse a grammar, but am having trouble understanding exactly how to use the library.
Basically, if the parser hits "Test" in the input stream, I'd like to emit 5 as the return value. (Later, I'd actually like to…
namezero
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3
votes
1 answer
Boost spirit permutation of rules
I have 2 type of expressions that I want parse and calculate the results.
Artimetic expressions: +,-,*,/ and sqrt() function;
Ex: "2 + 3 * sqrt(100*25)" -> should be calculated as 152
Functions: GetSubString() and ConcatenateStrings()
Ex:…
kyy
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- 11
3
votes
1 answer
Subscript operator[] error with Boost C++ Phoenix user-defined argument
With an existing Boost Phoenix (placeholder) argument, such as _1, I can use the array/subscript operator. For example, the following excerpt will display a 1.
int arr[4] = {1,2,3,4};
std::cout << _1[0](arr) << std::endl;
However, if I define my…
user2023370
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3
votes
1 answer
Cannot phoenix::bind qi::_val with boost 1.53 (regression ?)
The code below, using boost::spirit, used to work with boost 1.44 and boost 1.49:
qi::string("a_token")
[
boost::phoenix::bind(&node_t::some_func, *qi::_val, true)
]
I updated boost to version 1.53, but now this code does not compile anymore.…
neodelphi
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3
votes
1 answer
Evaluating result of boost::phoenix::insert
I'm having difficulties trying to evaluate the result of boost::phoenix::insert which inserts elements into a map. Similar to the regular std::map::insert the actor object returned by boost::phoenix::insert also returns a std::pair
Stacker
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3
votes
1 answer
Using boost::phoenix to adapt a BOOST_CHECK macro
During testing when using c++ 11 I have used the following construct:
std::for_each( coll.begin(), coll.end(),
[ &obj, expRes ]( const value_type& val )
{
BOOST_CHECK_EQUAL( expRes, obj.someFunc( val ) );
} );
I am currently…
mark
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3
votes
1 answer
Troubles with boost::phoenix::function
Using boost::phoenix::function I encountered some problems. As far as I know this lazy function requiries functor as its template parameter. I have to define a functor class/structure and then pass it as a template parameter for instantiation. But…
Oleksandr Karaberov
- 12,573
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2
votes
2 answers
What's the execution sequence of phoenix::lambda function?
I'm a newbie for boost phoenix, I wrote a small piece of code but it totally confuses me about the execution sequence, you can check the code
std::vector v;
v.push_back(1);
ph::for_each(v,
ph::lambda[ph::ref(cout)<<"a",
…
arthur.wang
- 21
- 1
2
votes
2 answers
boost spirit: parameter type when using semantic actions and phoenix
I use boost spirit to parse mathematical expressions and have run into a problem that I extracted into the following code.
There is a simple lexer with one token, having an attribute holding the matched string. The parser defines a single rule which…
user816098
- 262
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- 14
2
votes
2 answers
phoenix lambda and argument dereferencing
Can somebody show me how to implement an equivalent of the following using boost::phoenix lambda?
I know I could implement it in many other ways but I'm trying to learn the Phoenix lambda expressions and so far all my attempts in this example…
GxL Dev
- 23
- 3
2
votes
2 answers
Using Boost.Phoenix's operator ->*
I'm playing around with Phoenix v3 trying to figure out whether we should standardize on it instead of the current mix of Bind and Lambda. From the documentation I got the impression that it should be possible to simplify some expressions.
Currently…
Ben Swerts
- 78
- 3
2
votes
2 answers
boost.spirit "invalid static_cast" error when trying to count characters with phoenix bind
This code is not my actual code, but just illustrates the issue. I have a rule that matches 0 or more digits, and an action that is supposed to count them and return that count as the synthesized attribute.
The attribute of *qi::ascii::digit should…
Brian Bi
- 111,498
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2
votes
2 answers
How to use a sequence of statements in Boost.Phoenix together with std::transform?
I'd like to use Boost.Phoenix to create a lambda function that consists of a few lines of code and then "returns" a value so I can use it together with std::transform.
Like this:
std::transform(a.begin(), a.end(), b.begin(),
(
…
AbuBakr
- 968
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2
votes
1 answer
boost::spirit attribute assignment: struct is_nullary: base type fails to be a struct or class type
I have a boost::spirit parser that is supposed to simply assign a pointer to its attribute:
rule var_ref = var()(_r1) [
_val = new_>>(_1)
];
where…
Victor Mataré
- 2,446
- 2
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2
votes
1 answer
Boost phoenix member function operator fails to compile if function has overload
I want to use Boost phoenix member function operator for the class function that has overloads, like here.
The following example fails:
#include
#include
using namespace std;
using namespace…
MakeYouReal
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