ChaiScript/include/chaiscript/language/chaiscript_optimizer.hpp
2016-04-23 15:52:19 -06:00

121 lines
4.4 KiB
C++

// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009-2012, Jonathan Turner (jonathan@emptycrate.com)
// Copyright 2009-2016, Jason Turner (jason@emptycrate.com)
// http://www.chaiscript.com
#ifndef CHAISCRIPT_OPTIMIZER_HPP_
#define CHAISCRIPT_OPTIMIZER_HPP_
#include "chaiscript_eval.hpp"
namespace chaiscript {
namespace optimizer {
template<typename T>
auto child_at(const T &node, const size_t offset) {
if (node->identifier == AST_Node_Type::Compiled) {
return dynamic_cast<const eval::Compiled_AST_Node&>(*node).m_original_node->children[offset];
} else {
return node->children[offset];
}
}
template<typename T>
auto child_count(const T &node) {
if (node->identifier == AST_Node_Type::Compiled) {
return dynamic_cast<const eval::Compiled_AST_Node&>(*node).m_original_node->children.size();
} else {
return node->children.size();
}
}
template<typename T>
AST_NodePtr make_compiled_node(const AST_NodePtr &original_node, std::vector<AST_NodePtr> children, T callable)
{
return chaiscript::make_shared<AST_Node, eval::Compiled_AST_Node>(original_node, children, std::move(callable));
}
struct For_Loop_Optimizer {
AST_NodePtr optimize(const AST_NodePtr &for_node) {
if (for_node->identifier != AST_Node_Type::For) {
return for_node;
}
const auto eq_node = child_at(for_node, 0);
const auto binary_node = child_at(for_node, 1);
const auto prefix_node = child_at(for_node, 2);
if (eq_node->identifier == AST_Node_Type::Equation
&& child_count(eq_node) == 2
&& child_at(eq_node, 0)->identifier == AST_Node_Type::Var_Decl
&& child_at(eq_node, 1)->identifier == AST_Node_Type::Constant
&& binary_node->identifier == AST_Node_Type::Binary
&& binary_node->text == "<"
&& child_count(binary_node) == 2
&& child_at(binary_node, 0)->identifier == AST_Node_Type::Id
&& child_at(binary_node, 0)->text == child_at(child_at(eq_node,0), 0)->text
&& child_at(binary_node, 1)->identifier == AST_Node_Type::Constant
&& prefix_node->identifier == AST_Node_Type::Prefix
&& prefix_node->text == "++"
&& child_count(prefix_node) == 1
&& child_at(prefix_node, 0)->identifier == AST_Node_Type::Id
&& child_at(prefix_node, 0)->text == child_at(child_at(eq_node,0), 0)->text)
{
const Boxed_Value &begin = std::dynamic_pointer_cast<const eval::Constant_AST_Node>(child_at(eq_node, 1))->m_value;
const Boxed_Value &end = std::dynamic_pointer_cast<const eval::Constant_AST_Node>(child_at(binary_node, 1))->m_value;
const std::string &id = child_at(prefix_node, 0)->text;
if (begin.get_type_info().bare_equal(user_type<int>())
&& end.get_type_info().bare_equal(user_type<int>())) {
const auto start_int = boxed_cast<int>(begin);
const auto end_int = boxed_cast<int>(end);
const auto body = child_at(for_node, 3);
return make_compiled_node(for_node, {body},
[id, start_int, end_int](const std::vector<AST_NodePtr> &children, const chaiscript::detail::Dispatch_State &t_ss) {
assert(children.size() == 1);
chaiscript::eval::detail::Scope_Push_Pop spp(t_ss);
int i = start_int;
t_ss.add_object(id, var(&i));
try {
for (; i < end_int; ++i) {
try {
// Body of Loop
children[0]->eval(t_ss);
} catch (eval::detail::Continue_Loop &) {
// we got a continue exception, which means all of the remaining
// loop implementation is skipped and we just need to continue to
// the next iteration step
}
}
} catch (eval::detail::Break_Loop &) {
// loop broken
}
return void_var();
}
);
} else {
return for_node;
}
} else {
return for_node;
}
}
};
}
}
#endif