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Diffstat (limited to 'operations.cpp')
| -rw-r--r-- | operations.cpp | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/operations.cpp b/operations.cpp new file mode 100644 index 0000000000000..1b70dc4ed7a42 --- /dev/null +++ b/operations.cpp @@ -0,0 +1,153 @@ +// Copyright 2011 Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors +// may be used to endorse or promote products derived from this software +// without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include <cassert> + +#include <lua.hpp> + +#include "exceptions.hpp" +#include "operations.hpp" +#include "stack_cleaner.hpp" +#include "state.hpp" + + +/// Creates a module: i.e. a table with a set of methods in it. +/// +/// \param s The Lua state. +/// \param name The name of the module to create. +/// \param members The list of member functions to add to the module. +void +lutok::create_module(state& s, const std::string& name, + const std::map< std::string, cxx_function >& members) +{ + stack_cleaner cleaner(s); + s.new_table(); + for (std::map< std::string, cxx_function >::const_iterator + iter = members.begin(); iter != members.end(); iter++) { + s.push_string((*iter).first); + s.push_cxx_function((*iter).second); + s.set_table(-3); + } + s.set_global(name); +} + + +/// Loads and processes a Lua file. +/// +/// This is a replacement for luaL_dofile but with proper error reporting +/// and stack control. +/// +/// \param s The Lua state. +/// \param file The file to load. +/// \param nargs The number of arguments on the stack to pass to the file. +/// \param nresults The number of results to expect; -1 for any. +/// \param errfunc If not 0, index of a function in the stack to act as an +/// error handler. +/// +/// \return The number of results left on the stack. +/// +/// \throw error If there is a problem processing the file. +unsigned int +lutok::do_file(state& s, const std::string& file, const int nargs, + const int nresults, const int errfunc) +{ + assert(nresults >= -1); + const int height = s.get_top() - nargs; + + try { + s.load_file(file); + if (nargs > 0) + s.insert(-nargs - 1); + s.pcall(nargs, nresults == -1 ? LUA_MULTRET : nresults, + errfunc == 0 ? 0 : errfunc - 1); + } catch (const lutok::api_error& e) { + throw lutok::error("Failed to load Lua file '" + file + "': " + + e.what()); + } + + const int actual_results = s.get_top() - height; + assert(nresults == -1 || actual_results == nresults); + assert(actual_results >= 0); + return static_cast< unsigned int >(actual_results); +} + + +/// Processes a Lua script. +/// +/// This is a replacement for luaL_dostring but with proper error reporting +/// and stack control. +/// +/// \param s The Lua state. +/// \param str The string to process. +/// \param nargs The number of arguments on the stack to pass to the chunk. +/// \param nresults The number of results to expect; -1 for any. +/// \param errfunc If not 0, index of a function in the stack to act as an +/// error handler. +/// +/// \return The number of results left on the stack. +/// +/// \throw error If there is a problem processing the string. +unsigned int +lutok::do_string(state& s, const std::string& str, const int nargs, + const int nresults, const int errfunc) +{ + assert(nresults >= -1); + const int height = s.get_top() - nargs; + + try { + s.load_string(str); + if (nargs > 0) + s.insert(-nargs - 1); + s.pcall(nargs, nresults == -1 ? LUA_MULTRET : nresults, + errfunc == 0 ? 0 : errfunc - 1); + } catch (const lutok::api_error& e) { + throw lutok::error("Failed to process Lua string '" + str + "': " + + e.what()); + } + + const int actual_results = s.get_top() - height; + assert(nresults == -1 || actual_results == nresults); + assert(actual_results >= 0); + return static_cast< unsigned int >(actual_results); +} + + +/// Convenience function to evaluate a Lua expression. +/// +/// \param s The Lua state. +/// \param expression The textual expression to evaluate. +/// \param nresults The number of results to leave on the stack. Must be +/// positive. +/// +/// \throw api_error If there is a problem evaluating the expression. +void +lutok::eval(state& s, const std::string& expression, const int nresults) +{ + assert(nresults > 0); + do_string(s, "return " + expression, 0, nresults, 0); +} |