opcodes.h

#ifndef WREPORT_OPCODE_H
#define WREPORT_OPCODE_H
 
#include <wreport/varinfo.h>
#include <wreport/error.h>
#include <vector>
#include <cstdio>
 
namespace wreport {
 
struct Opcodes
{
    const Varcode* begin;
    const Varcode* end;
 
    Opcodes(const std::vector<Varcode>& vals) : begin(vals.data()), end(begin + vals.size()) {}
    Opcodes(const Varcode* begin, const Varcode* end)
        : begin(begin), end(end) {}
 
    Opcodes(const Opcodes& o) = default;
    Opcodes& operator=(const Opcodes& o) = default;
 
    Varcode operator[](unsigned i) const
    {
        if (begin + i > end)
            return 0;
        else
            return begin[i];
    }
 
    unsigned size() const { return end - begin; }
 
    bool empty() const { return begin == end; }
 
    Varcode pop_left()
    {
        if (empty()) throw error_consistency("cannot do pop_left on an empty opcode sequence");
        return *begin++;
    }
 
    Opcodes pop_left(unsigned count)
    {
        if (size() < count)
            error_consistency::throwf("cannot do pop_left(%u) on an opcode sequence of only %u elements", count, size());
        Opcodes res(begin, begin + count);
        begin += count;
        return res;
    }
 
    Varcode head() const
    {
        if (begin == end)
            return 0;
        return *begin;
    }
 
    Opcodes next() const
    {
        if (begin == end)
            return *this;
        else
            return Opcodes(begin+1, end);
    }
 
    Opcodes sub(unsigned skip) const
    {
        if (begin + skip > end)
            return Opcodes(end, end);
        else
            return Opcodes(begin + skip, end);
    }
 
    Opcodes sub(unsigned skip, unsigned len) const
    {
        if (begin + skip > end)
            return Opcodes(end, end);
        else if (begin + skip + len >= end)
            return Opcodes(begin + skip, end);
        else
            return Opcodes(begin + skip, begin + skip + len);
    }
 
    void print(FILE* out) const;
};
 
}
#endif