Move some stuff out of LuaStack
This commit is contained in:
234
luprex/cpp/core/keywords.cpp
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234
luprex/cpp/core/keywords.cpp
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#include "wrap-string.hpp"
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#include "keywords.hpp"
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#include "util.hpp"
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static LuaToken token_error("error");
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static LuaToken token_found("found");
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LuaKeywordParser::LuaKeywordParser(const LuaCoreStack &LS0, LuaSlot slot)
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: keytab(slot.index()), LS(LS0.state()) {
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lua_State *L = LS0.state();
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lua_pushnil(L); found.index_ = lua_gettop(L);
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lua_pushnil(L); error.index_ = lua_gettop(L);
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lua_pushnil(L); key.index_ = lua_gettop(L);
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lua_pushnil(L); val.index_ = lua_gettop(L);
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istable = LS.istable(keytab);
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if (istable) {
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LS.rawget(found, keytab, token_found);
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if (!LS.istable(found)) {
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LS.set(found, LuaNewTable);
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LS.rawset(keytab, token_found, found);
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}
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}
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}
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bool LuaKeywordParser::optional(LuaSlot out, std::string_view kw) {
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if (!istable) {
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LS.set(out, LuaNil);
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return false;
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}
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LS.rawget(out, keytab, kw);
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if (!LS.isnil(out)) {
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LS.rawset(found, kw, true);
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return true;
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} else {
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return false;
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}
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};
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bool LuaKeywordParser::required(LuaSlot out, std::string_view kw) {
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if (!istable) {
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LS.set(out, LuaNil);
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return false;
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}
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LS.rawget(out, keytab, kw);
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if (!LS.isnil(out)) {
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LS.rawset(found, kw, true);
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return true;
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} else {
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LS.rawget(error, keytab, token_error);
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if (!LS.isstring(error)) {
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LS.rawset(keytab, token_error, util::ss("required keyword argument not present: ", kw));
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}
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return false;
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}
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};
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eng::string LuaKeywordParser::check() {
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if (!istable) {
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return "keyword arguments must be a table";
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}
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LS.rawget(error, keytab, token_error);
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auto str = LS.trystring(error);
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if (str.has_value()) return str.value();
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return "";
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}
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eng::string LuaKeywordParser::final_check() {
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if (!istable) {
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return "keyword arguments must be a table";
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}
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LS.rawget(error, keytab, token_error);
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auto str = LS.trystring(error);
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if (str.has_value()) return str.value();
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LS.set(key, LuaNil);
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while (LS.next(keytab, key, val)) {
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if (LS.istoken(key)) {
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continue;
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}
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auto kw = LS.trystringview(key);
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if (!kw.has_value()) {
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return "keyword arguments include a non-string key";
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}
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LS.rawget(val, found, key);
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if (!LS.rawequal(val, true)) {
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return util::ss("unrecognized keyword argument: ", kw.value());
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}
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}
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return "";
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}
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void LuaKeywordParser::check_throw() {
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eng::string err = check();
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if (!err.empty()) {
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luaL_error(LS.state(), "%s", err.c_str());
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}
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}
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void LuaKeywordParser::final_check_throw() {
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eng::string err = final_check();
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if (!err.empty()) {
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luaL_error(LS.state(), "%s", err.c_str());
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}
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}
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static const char *kwdoc =
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"|Parse lua keyword arguments."
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"|"
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"|The keywords module is used to help parse keyword arguments"
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"|for functions. The error handling is strong, it throws useful"
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"|error messages when the caller passes in incorrect arguments."
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"|This is a typical example of how it is used:"
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"|"
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"| function drawrect(args)"
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"| local x1,y1 = keywords.required(args, 'x1', 'y1')"
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"| local x2,y2 = keywords.required(args, 'x2', 'y2')"
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"| local color = keywords.optional(args, 'color')"
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"| keywords.finalcheckthrow(args)"
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"| ..."
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"| end"
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"|"
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"|The function above expects four required keyword arguments and one"
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"|optional one. The example code above handles all the following"
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"|error cases:"
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"|"
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"| * That 'args' actually is a table."
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"| * That the required keywords x1,y1,x2,y2 are all present."
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"| * That the table doesn't contain extraneous unknown keywords."
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"|"
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"|The functions keywords.required and keywords.optional don't throw"
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"|lua errors. Instead, they store status information in the keyword"
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"|table itself. Using the status information, the function"
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"|keywords.finalcheckthrow will throw an error if anything went wrong"
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"|along the way."
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"|"
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"|You can check errors when you're not finished parsing using the"
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"|function keywords.checkthrow() instead of keywords.finalcheckthrow()."
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"|Unlike finalcheckthrow, this function doesn't verify the absence of"
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"|extraneous keywords, which can only be done at the end."
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"|"
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"|If you don't want to throw errors at all, you can use"
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"|keywords.finalcheck() instead of keywords.finalcheckthrow()."
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"|This returns the error message, rather than throwing it."
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"|";
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LuaDefine(keywords_optional, "table, keyword, keyword, keyword...", kwdoc) {
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LuaArg table;
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LuaExtraArgs keywords;
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LuaDefStack LS(L, table, keywords);
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LuaKeywordParser KP(LS, table);
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if (keywords.size() < 1) {
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luaL_error(L, "expected at least one keyword");
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return 0;
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}
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for (int i = 0; i < keywords.size(); i++) {
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eng::string kw = LS.ckstring(keywords[i], "keyword");
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KP.optional(keywords[i], kw);
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}
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// Return the results without using LS.result, because it doesn't
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// support multiple return values.
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lua_settop(L, keywords[keywords.size() - 1].index());
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return keywords.size();
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}
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LuaDefine(keywords_required, "table, keyword, keyword, keyword...", kwdoc) {
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LuaArg table;
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LuaExtraArgs keywords;
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LuaDefStack LS(L, table, keywords);
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LuaKeywordParser KP(LS, table);
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if (keywords.size() < 1) {
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luaL_error(L, "expected at least one keyword");
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return 0;
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}
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for (int i = 0; i < keywords.size(); i++) {
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eng::string kw = LS.ckstring(keywords[i], "keyword");
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KP.required(keywords[i], kw);
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}
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// Return the results without using LS.result, because it doesn't
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// support multiple return values.
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lua_settop(L, keywords[keywords.size() - 1].index());
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return keywords.size();
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}
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LuaDefine(keywords_check, "table", kwdoc) {
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LuaArg table;
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LuaRet result;
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LuaDefStack LS(L, table, result);
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LuaKeywordParser KP(LS, table);
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eng::string err = KP.check();
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if (!err.empty()) {
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LS.set(result, err);
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}
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return LS.result();
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}
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LuaDefine(keywords_finalcheck, "table", kwdoc) {
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LuaArg table;
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LuaRet result;
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LuaDefStack LS(L, table, result);
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LuaKeywordParser KP(LS, table);
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eng::string err = KP.final_check();
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if (!err.empty()) {
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LS.set(result, err);
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}
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return LS.result();
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}
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LuaDefine(keywords_checkthrow, "table", kwdoc) {
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LuaArg table;
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LuaDefStack LS(L, table);
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LuaKeywordParser KP(LS, table);
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KP.check_throw();
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return LS.result();
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}
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LuaDefine(keywords_finalcheckthrow, "table", kwdoc) {
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LuaArg table;
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LuaDefStack LS(L, table);
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LuaKeywordParser KP(LS, table);
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KP.final_check_throw();
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return LS.result();
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}
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