90 lines
3.4 KiB
C++
90 lines
3.4 KiB
C++
////////////////////////////////////////////////////////////////////
|
|
//
|
|
// LuaKeywordParser
|
|
//
|
|
// This is a helper class to help parse tables full of keywords.
|
|
// It is meant to make it easier to write LuaDefine functions that
|
|
// accept keyword arguments. It helps with the following tasks:
|
|
//
|
|
// * It makes sure the keyword table actually is a table.
|
|
//
|
|
// * It makes sure that all required keywords are present.
|
|
//
|
|
// * It makes sure that you didn't put anything that isn't a
|
|
// known keyword into the keyword table.
|
|
//
|
|
// This module adds two fields to the table:
|
|
//
|
|
// [ERROR] - stores an error message, initially nil.
|
|
// [FOUND] - the set of keywords successfully parsed.
|
|
//
|
|
// If at any time, this module detects an error, it doesn't throw.
|
|
// Instead, it stores an error report in the table key [ERROR].
|
|
// Later, you can check for an error string using the function
|
|
// final_check or final_check_throw. If an error is
|
|
// detected when there is already an error report in the table,
|
|
// the error report is not overwritten, so therefore, the error
|
|
// reported is always the first error detected.
|
|
//
|
|
// When this module finds a keyword in the table, it adds the keyword
|
|
// to the [FOUND] set of all keywords successfully parsed.
|
|
//
|
|
// If the keyword table that you pass in isn't a table at all,
|
|
// then the keyword-fetching functions will always return false.
|
|
// Later, when you call 'check', an appropriate error will be
|
|
// generated.
|
|
//
|
|
// The lua module 'keywords' contains the same functions as this
|
|
// C++ class. You can write code where a C++ function does some
|
|
// of the parsing, and the lua code does the rest of the parsing.
|
|
//
|
|
////////////////////////////////////////////////////////////////////
|
|
|
|
#pragma once
|
|
|
|
#include "luastack.hpp"
|
|
|
|
class LuaKeywordParser {
|
|
private:
|
|
LuaVar found, error, key, val;
|
|
LuaSpecial keytab;
|
|
LuaCoreStack LS;
|
|
bool istable;
|
|
|
|
void init(const lua_State *L, int slot);
|
|
public:
|
|
LuaKeywordParser(const LuaCoreStack &LS, LuaSlot slot);
|
|
|
|
// Fetch the value of the keyword. If the keyword is found, then the
|
|
// keyword is added to the [FOUND] set, the value is returned in slot,
|
|
// and returns true. Otherwise, sets slot to nil and returns false.
|
|
bool optional(LuaSlot slot, std::string_view kw);
|
|
|
|
// Fetch the value of the keyword. If the keyword is found, then the
|
|
// keyword is added to the [FOUND] set, the value is returned in slot,
|
|
// and returns true. Otherwise, sets slot to nil, returns false, and
|
|
// stores an [ERROR] report in the keyword table.
|
|
bool required(LuaSlot slot, std::string_view kw);
|
|
|
|
// Check if there are any errors so far, by checking for an [ERROR]
|
|
// report in the keyword table. If any error has been
|
|
// detected, returns an error message, otherwise, returns empty
|
|
// string.
|
|
eng::string check();
|
|
|
|
// Check if there are any errors so far, by checking for an [ERROR]
|
|
// report in the keyword table. Also check that all keyword
|
|
// arguments present in the table are in the [FOUND] set. If there are
|
|
// any errors, returns an error message, otherwise returns empty string.
|
|
eng::string final_check();
|
|
|
|
// If check() returns an error, throws the error using luaL_error.
|
|
void check_throw();
|
|
|
|
// If final_check() returns an error, throws the error using luaL_error.
|
|
void final_check_throw();
|
|
|
|
// Fetch the state pointer.
|
|
lua_State *state() const { return LS.state(); }
|
|
};
|