xo-tokenizer2/xo-reader/src/reader/envframestack.cpp

139 lines
3.7 KiB
C++

/* file envframestack.cpp
*
* author: Roland Conybeare
*/
#include "envframestack.hpp"
#include "pretty_envframestack.hpp"
#include "pretty_localenv.hpp"
namespace xo {
using xo::scm::LocalSymtab;
using xo::scm::Variable;
namespace scm {
bp<SymbolTable>
envframestack::top_envframe() const {
std::size_t z = stack_.size();
if (z == 0) {
throw std::runtime_error
("parser::top_exprstate: unexpected empty stack");
}
return stack_[z-1].get();
}
void
envframestack::push_envframe(const rp<SymbolTable> & frame)
{
constexpr bool c_debug_flag = true;
scope log(XO_DEBUG(c_debug_flag),
xtag("frame", frame));
std::size_t z = stack_.size();
stack_.resize(z+1);
stack_[z] = frame;
}
rp<SymbolTable>
envframestack::pop_envframe() {
constexpr bool c_debug_flag = true;
scope log(XO_DEBUG(c_debug_flag));
std::size_t z = stack_.size();
if (z > 0) {
//std::unique_ptr<exprstate> top = std::move(stack_[z-1]);
rp<SymbolTable> retval = stack_.at(z-1);
stack_.resize(z-1);
return retval;
} else {
return nullptr;
}
}
bp<Expression>
envframestack::lookup(const std::string & x) const {
for (std::size_t i = 0, z = this->size(); i < z; ++i) {
const auto & frame = (*this)[i];
auto retval = frame->lookup_local(x);
if (retval)
return retval;
}
return bp<Variable>::from_native(nullptr);
}
void
envframestack::upsert(bp<Variable> x) {
/* upsert should always happen in the innermost lexical context.
* We are providing new variable binding (perhaps shadowing an existing binding)
*/
this->top_envframe()->upsert_local(x);
}
void
envframestack::print(std::ostream & os) const {
os << "<envframestack"
<< xtag("size", stack_.size())
<< std::endl;
for (std::size_t i = 0, z = stack_.size(); i < z; ++i) {
os << " [" << z-i-1 << "] "
<< stack_[i]
<< std::endl;
}
os << ">" << std::endl;
}
bool
envframestack::pretty_print(const ppindentinfo & ppii) const
{
ppstate * pps = ppii.pps();
if (ppii.upto()) {
if (stack_.size() > 1)
return false;
if (!pps->print_upto("<envframestack"))
return false;
if (!pps->print_upto_tag("size", stack_.size()))
return false;
if ((stack_.size() > 0)
&& !pps->print_upto_tag("[0]", stack_[0]))
{
return false;
}
pps->write(">");
return true;
} else {
pps->write("<envframestack");
pps->newline_pretty_tag(ppii.ci1(), "size", stack_.size());
for (std::size_t i = 0, z = stack_.size(); i < z; ++i) {
std::string i_str = tostr("[", z-i-1, "]");
pps->newline_pretty_tag(ppii.ci1(), i_str, stack_[i]);
}
pps->write(">");
return false;
}
}
} /*namespace scm*/
} /*namespace xo*/
/* end envframestack.cpp */