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|
/*
* @LANG: c++
*/
#include <iostream>
#include <string.h>
using namespace std;
#define TK_Dlit 192
#define TK_Slit 193
#define TK_Float 194
#define TK_Id 195
#define TK_NameSep 197
#define TK_Arrow 211
#define TK_PlusPlus 212
#define TK_MinusMinus 213
#define TK_ArrowStar 214
#define TK_DotStar 215
#define TK_ShiftLeft 216
#define TK_ShiftRight 217
#define TK_IntegerDecimal 218
#define TK_IntegerOctal 219
#define TK_IntegerHex 220
#define TK_EqualsEquals 223
#define TK_NotEquals 224
#define TK_AndAnd 225
#define TK_OrOr 226
#define TK_MultAssign 227
#define TK_DivAssign 228
#define TK_PercentAssign 229
#define TK_PlusAssign 230
#define TK_MinusAssign 231
#define TK_AmpAssign 232
#define TK_CaretAssign 233
#define TK_BarAssign 234
#define TK_DotDotDot 240
#define TK_Whitespace 241
#define TK_Comment 242
#define BUFSIZE 4096
char buf[BUFSIZE];
struct Scanner
{
int cs, act;
char *tokstart, *tokend;
void token( int tok );
void run();
void init( );
void execute( char *data, int len );
int finish( );
};
%%{
machine Scanner;
main := |*
# Single and double literals.
( 'L'? "'" ( [^'\\\n] | /\\./ )* "'" )
=> { token( TK_Slit );};
( 'L'? '"' ( [^"\\\n] | /\\./ )* '"' )
=> { token( TK_Dlit );};
# Identifiers
( [a-zA-Z_] [a-zA-Z0-9_]* )
=>{ token( TK_Id );};
# Floating literals.
fract_const = digit* '.' digit+ | digit+ '.';
exponent = [eE] [+\-]? digit+;
float_suffix = [flFL];
( fract_const exponent? float_suffix? |
digit+ exponent float_suffix? )
=> { token( TK_Float );};
# Integer decimal. Leading part buffered by float.
( ( '0' | [1-9] [0-9]* ) [ulUL]{0,3} )
=> { token( TK_IntegerDecimal );};
# Integer octal. Leading part buffered by float.
( '0' [0-9]+ [ulUL]{0,2} )
=> { token( TK_IntegerOctal );};
# Integer hex. Leading 0 buffered by float.
( '0' ( 'x' [0-9a-fA-F]+ [ulUL]{0,2} ) )
=> { token( TK_IntegerHex );};
# Only buffer the second item, first buffered by symbol. */
'::' => {token( TK_NameSep );};
'==' => {token( TK_EqualsEquals );};
'!=' => {token( TK_NotEquals );};
'&&' => {token( TK_AndAnd );};
'||' => {token( TK_OrOr );};
'*=' => {token( TK_MultAssign );};
'/=' => {token( TK_DivAssign );};
'%=' => {token( TK_PercentAssign );};
'+=' => {token( TK_PlusAssign );};
'-=' => {token( TK_MinusAssign );};
'&=' => {token( TK_AmpAssign );};
'^=' => {token( TK_CaretAssign );};
'|=' => {token( TK_BarAssign );};
'++' => {token( TK_PlusPlus );};
'--' => {token( TK_MinusMinus );};
'->' => {token( TK_Arrow );};
'->*' => {token( TK_ArrowStar );};
'.*' => {token( TK_DotStar );};
# Three char compounds, first item already buffered. */
'...' => { token( TK_DotDotDot );};
# Single char symbols.
( punct - [_"'] ) => { token( tokstart[0] );};
action comment {
token( TK_Comment );
}
# Comments and whitespace.
'/*' ( any* $0 '*/' @1 ) => comment;
'//' ( any* $0 '\n' @1 ) => comment;
( any - 33..126 )+ => { token( TK_Whitespace );};
*|;
}%%
%% write data;
void Scanner::init( )
{
%% write init;
}
/* Returns the count of bytes still in the buffer
* (shifted to the biginning) */
void Scanner::execute( char *data, int len )
{
char *p = data;
char *pe = data + len;
%% write exec;
}
int Scanner::finish( )
{
%% write eof;
if ( cs == Scanner_error )
return -1;
if ( cs >= Scanner_first_final )
return 1;
return 0;
}
void Scanner::token( int tok )
{
const char *data = tokstart;
int len = tokend - tokstart;
cout << "<" << tok << "> ";
for ( int i = 0; i < len; i++ )
cout << data[i];
cout << '\n';
}
void test( char *buf )
{
int len = strlen( buf );
std::ios::sync_with_stdio(false);
Scanner scanner;
scanner.init();
scanner.execute( buf, len );
if ( scanner.cs == Scanner_error ) {
/* Machine failed before finding a token. */
cout << "PARSE ERROR" << endl;
}
/* FIXME: Last token may get lost. */
scanner.finish();
}
int main()
{
test(
"\"\\\"hi\" /*\n"
"*/\n"
"44 .44\n"
"44. 44\n"
"44 . 44\n"
"44.44\n"
"_hithere22\n"
"\n"
);
test(
"'\\''\"\\n\\d'\\\"\"\n"
"hi\n"
"99\n"
".99\n"
"99e-4\n"
"->*\n"
"||\n"
"0x98\n"
"0x\n"
"//\n"
"/* * */\n"
);
test(
"'\n"
"'\n"
);
}
#ifdef _____OUTPUT_____
<192> "\"hi"
<241>
<242> /*
*/
<241>
<218> 44
<241>
<194> .44
<241>
<194> 44.
<241>
<218> 44
<241>
<218> 44
<241>
<46> .
<241>
<218> 44
<241>
<194> 44.44
<241>
<195> _hithere22
<193> '\''
<192> "\n\d'\""
<241>
<195> hi
<241>
<218> 99
<241>
<194> .99
<241>
<194> 99e-4
<241>
<214> ->*
<241>
<226> ||
<241>
<220> 0x98
<241>
<218> 0
<195> x
<241>
<242> //
<242> /* * */
PARSE ERROR
#endif
|
