keyword.cpp

由一个古老的BASIC解释器改进而成, 保留了ANSI C固有的艺术美感.

// keyword.cpp

#include "keyword.h"
#include "util.h"

using util::dim_array;

#include <iostream>
#include <algorithm>
#include <iterator>
#include <functional>
#include <cctype>

// I don't understand why, but with this using the older version
// of C++ Builder fails.
#if __BORLANDC__ >= 0x0560
using std::toupper;
#endif

namespace {

struct keycode {
	std::string key;
	BlCode code;
	keycode (const char * str, BlCode c) :
		key (str), code (c)
	{ }
};

// Can't declare const on Borland or fail at instantiate find_if,
// don't know why.
#ifdef __BORLANDC__
#define const_keycode keycode
#else
#define const_keycode const keycode
#endif

const_keycode table []= {
	keycode ("END",         keyEND),
	keycode ("LIST",        keyLIST),
	keycode ("REM",         keyREM),
	keycode ("LOAD",        keyLOAD),
	keycode ("SAVE",        keySAVE),
        keycode ("EXIT",        keyEXIT),
	keycode ("NEW",         keyNEW),
	keycode ("RUN",         keyRUN),
	keycode ("PRINT",       keyPRINT),
	keycode ("FOR",         keyFOR),
	keycode ("NEXT",        keyNEXT),
	keycode ("TO",          keyTO),
	keycode ("STEP",        keySTEP),
	keycode ("IF",          keyIF),
	keycode ("THEN",        keyTHEN),
	keycode ("ELSE",        keyELSE),
	keycode ("TRON",        keyTRON),
	keycode ("TROFF",       keyTROFF),
	keycode ("LET",         keyLET),
	keycode ("GOTO",        keyGOTO),
	keycode ("STOP",        keySTOP),
	keycode ("CONT",        keyCONT),
	keycode ("CLEAR",       keyCLEAR),
	keycode ("GOSUB",       keyGOSUB),
	keycode ("RETURN",      keyRETURN),
	keycode ("POKE",        keyPOKE),
	keycode ("DATA",        keyDATA),
	keycode ("READ",        keyREAD),
	keycode ("RESTORE",     keyRESTORE),
	keycode ("INPUT",       keyINPUT),
	keycode ("LINE",        keyLINE),
	keycode ("RANDOMIZE",   keyRANDOMIZE),
	keycode ("PLEASE",      keyPLEASE),
	keycode ("AUTO",        keyAUTO),
	keycode ("DIM",         keyDIM),
	keycode ("SYSTEM",      keySYSTEM),
        keycode ("ON",          keyON),
        keycode ("ERROR",       keyERROR),
        keycode ("OPEN",        keyOPEN),
        keycode ("CLOSE",       keyCLOSE),
        keycode ("OUTPUT",      keyOUTPUT),
        keycode ("AS",          keyAS),
	keycode ("LOCATE",      keyLOCATE),
	keycode ("CLS",         keyCLS),
	keycode ("APPEND",      keyAPPEND),
	keycode ("WRITE",       keyWRITE),
	keycode ("MODE",        keyMODE),
	keycode ("MOVE",        keyMOVE),
	keycode ("COLOR",       keyCOLOR),
        keycode ("GET",         keyGET),
	keycode ("LABEL",       keyLABEL),
	keycode ("DELIMITER",   keyDELIMITER),
	keycode ("REPEAT",      keyREPEAT),
	keycode ("UNTIL",       keyUNTIL),
        keycode ("WHILE",       keyWHILE),
        keycode ("WEND",        keyWEND),
	keycode ("PLOT",        keyPLOT),
        keycode ("POPEN",       keyPOPEN),
        keycode ("RESUME",      keyRESUME),
	keycode ("DELETE",      keyDELETE),
	keycode ("LOCAL",       keyLOCAL),
	keycode ("RANDOM",      keyRANDOM),
	keycode ("PUT",         keyPUT),
        keycode ("FIELD",       keyFIELD),
        keycode ("LSET",        keyLSET),
        keycode ("RSET",        keyRSET),
	keycode ("SOCKET",      keySOCKET),
	keycode ("DRAW",        keyDRAW),
	keycode ("DEF",         keyDEF),
	keycode ("FN",          keyFN),
        keycode ("ERASE",       keyERASE),
        keycode ("SWAP",        keySWAP),
        keycode ("SYMBOL",      keySYMBOL),
        keycode ("ZONE",        keyZONE),
        keycode ("POP",         keyPOP),
	keycode ("NAME",        keyNAME),
	keycode ("KILL",        keyKILL),
	keycode ("FILES",       keyFILES),
	keycode ("PAPER",       keyPAPER),
	keycode ("PEN",         keyPEN),
	keycode ("SHELL",       keySHELL),
	keycode ("MERGE",       keyMERGE),
	keycode ("CHDIR",       keyCHDIR),
	keycode ("MKDIR",       keyMKDIR),
	keycode ("RMDIR",       keyRMDIR),
	keycode ("BREAK",       keyBREAK),
	keycode ("SYNCHRONIZE", keySYNCHRONIZE),
	keycode ("PAUSE",       keyPAUSE),
	keycode ("CHAIN",       keyCHAIN),
	keycode ("STR",         keySTR),
	keycode ("REAL",        keyREAL),
	keycode ("ENVIRON",     keyENVIRON),
	keycode ("EDIT",        keyEDIT),
	keycode ("DRAWR",       keyDRAWR),
	keycode ("PLOTR",       keyPLOTR),
	keycode ("MOVER",       keyMOVER),
	keycode ("POKE16",      keyPOKE16),
	keycode ("POKE32",      keyPOKE32),
	keycode ("RENUM",       keyRENUM),
	keycode ("CIRCLE",      keyCIRCLE),
	keycode ("MASK",        keyMASK),
	keycode ("WINDOW",      keyWINDOW),
	keycode ("GRAPHICS",    keyGRAPHICS),

	keycode ("MID$",        keyMID_S),
	keycode ("LEFT$",       keyLEFT_S),
	keycode ("RIGHT$",      keyRIGHT_S),
	keycode ("CHR$",        keyCHR_S),
	keycode ("ENVIRON$",    keyENVIRON_S),
	keycode ("STRING$",     keySTRING_S),
	keycode ("OSFAMILY$",   keyOSFAMILY_S),
	keycode ("HEX$",        keyHEX_S),
        keycode ("SPACE$",      keySPACE_S),
        keycode ("UPPER$",      keyUPPER_S),
        keycode ("LOWER$",      keyLOWER_S),
        keycode ("STR$",        keySTR_S),
        keycode ("OCT$",        keyOCT_S),
        keycode ("BIN$",        keyBIN_S),
        keycode ("INKEY$",      keyINKEY_S),
	keycode ("PROGRAMARG$", keyPROGRAMARG_S),
	keycode ("DATE$",       keyDATE_S),
	keycode ("TIME$",       keyTIME_S),
	keycode ("INPUT$",      keyINPUT_S),
	keycode ("MKI$",        keyMKI_S),
	keycode ("MKS$",        keyMKS_S),
	keycode ("MKD$",        keyMKD_S),
	keycode ("MKL$",        keyMKL_S),
	keycode ("TRIM$",       keyTRIM_S),
	keycode ("LTRIM$",      keyLTRIM_S),
	keycode ("RTRIM$",      keyRTRIM_S),
	keycode ("OSNAME$",     keyOSNAME_S),

        keycode ("ASC",         keyASC),
	keycode ("LEN",         keyLEN),
	keycode ("PEEK",        keyPEEK),
	keycode ("PROGRAMPTR",  keyPROGRAMPTR),
	keycode ("RND",         keyRND),
	keycode ("INT",         keyINT),
	keycode ("SIN",         keySIN),
	keycode ("COS",         keyCOS),
	keycode ("PI",          keyPI),
	keycode ("TAN",         keyTAN),
	keycode ("SQR",         keySQR),
	keycode ("ASIN",        keyASIN),
	keycode ("ACOS",        keyACOS),
	keycode ("INSTR",       keyINSTR),
	keycode ("ATAN",        keyATAN),
	keycode ("ABS",         keyABS),
	keycode ("USR",         keyUSR),
        keycode ("VAL",         keyVAL),
	keycode ("EOF",         keyEOF),
	keycode ("VARPTR",      keyVARPTR),
	keycode ("SYSVARPTR",   keySYSVARPTR),
	keycode ("SGN",         keySGN),
	keycode ("LOG",         keyLOG),
	keycode ("LOG10",       keyLOG10),
	keycode ("EXP",         keyEXP),
	keycode ("TIME",        keyTIME),
        keycode ("ERR",         keyERR),
        keycode ("ERL",         keyERL),
        keycode ("CVI",         keyCVI),
        keycode ("CVS",         keyCVS),
        keycode ("CVD",         keyCVD),
        keycode ("CVL",         keyCVL),
        keycode ("MIN",         keyMIN),
        keycode ("MAX",         keyMAX),
	keycode ("CINT",        keyCINT),
	keycode ("FIX",         keyFIX),
	keycode ("XMOUSE",      keyXMOUSE),
	keycode ("YMOUSE",      keyYMOUSE),
	keycode ("XPOS",        keyXPOS),
	keycode ("YPOS",        keyYPOS),
	keycode ("PEEK16",      keyPEEK16),
	keycode ("PEEK32",      keyPEEK32),

	keycode ("NOT",         keyNOT),
	keycode ("OR",          keyOR),
	keycode ("AND",         keyAND),
        keycode ("TAB",         keyTAB),
        keycode ("SPC",         keySPC),
        keycode ("AT",          keyAT),
	keycode ("XOR",         keyXOR),
	keycode ("MOD",         keyMOD),
	keycode ("USING",       keyUSING),

	// table_end points here, then if find_if (table, table_end, ...)
	// fails the result is:
	keycode ("???",         0),
};

const_keycode * table_end= table + dim_array (table) - 1;

class key_is : public std::unary_function <keycode, bool> {
public:
	key_is (const std::string & str) : str (str)
	{ }
	bool operator () (const keycode & k) const
	{ return k.key == str; }
private:
	const std::string & str;
};

class code_is : public std::unary_function <keycode, bool> {
public:
	code_is (BlCode code) : code (code)
	{ }
	bool operator () (const keycode & k) const
	{ return k.code == code; }
private:
	BlCode code;
};

} // namespace

BlCode keyword (const std::string & str)
{
	#if __GNUC__ == 2 && __GNUC_MINOR__ <= 95
	// Apparently before gcc 2.95.3 there is no push_back in
	// string, but there is no method to evaluate te third number,
	// then we disallow it in all 2.95 versions.
	std::string stru (str.size (), 0);
	std::transform (str.begin (), str.end (), stru.begin (), toupper);
	#else
	std::string stru;
	std::transform (str.begin (), str.end (),
		std::back_inserter (stru), toupper);
	#endif
	return std::find_if (table, table_end, key_is (stru) )->code;
}

std::string decodekeyword (BlCode s)
{
	return std::find_if (table, table_end, code_is (s) )->key;
}

// Fin de keyword.cpp