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#include "const.h"
#include "scan.h"
#include "ctype.h"
#include "string.h"
#include "utils.h"
#include "io.h"
void scanner_init( Scanner *s, char *src )
{
s->src = src;
scanner_reset( s );
}
void scanner_reset( Scanner *s )
{
s->peek = ' ';
s->row = 1;
s->col = 1;
s->pos = s->src;
}
void scanner_done( Scanner *s )
{
}
static char get_char( Scanner *s )
{
char c;
c = *s->pos;
s->pos++;
s->peek = c;
return c;
}
static void skip_whitespace( Scanner *s )
{
for( ; ; get_char( s ) ) {
s->col++;
if( s->peek == ' ' || s->peek == '\t' ) {
continue;
} else if( s->peek == '\n' ) {
s->row++;
s->col = 1;
break;
} else if( s->peek == '\0' ) {
break;
} else {
break;
}
}
}
void scanner_skip_line( Scanner *s )
{
while( s->peek != '\0' && s->peek != '\n' ) {
s->col++;
get_char( s );
}
if( s->peek == '\n' ) {
s->col++;
}
}
Symbol get_int( Scanner *s )
{
Symbol sym;
sym.sym = S_number;
sym.data.n = 0;
do {
sym.data.n = sym.data.n * 10 + ( s->peek - '0' );
get_char( s );
} while( s->peek != '\0' && isdigit( s->peek ) );
return sym;
}
Symbol get_ident_or_label( Scanner *s )
{
Symbol newSym;
char *p;
newSym.sym = S_ident;
newSym.data.s[0] = '\0';
p = newSym.data.s;
do {
*p++ = s->peek;
get_char( s );
} while( ( isalnum( s->peek ) || s->peek == '_' ) && !isspace( s->peek ) && ( s->peek != '\0' ) && ( s->peek != ':' ) && ( p - newSym.data.s < MAX_IDENT_LEN ) );
if( s->peek == ':' ) {
newSym.sym = S_label;
get_char( s );
}
*p = '\0';
return newSym;
}
Symbol scanner_scan( Scanner *s )
{
Symbol sym;
if( s->peek == '\0' ) {
sym.sym = S_eof;
if( s->debug ) {
print( "SCANNER(EOF)" );
}
return sym;
}
skip_whitespace( s );
if( s->peek == '\0' ) {
sym.sym = S_eof;
if( s->debug ) {
print( "SCANNER(EOF)" );
}
return sym;
}
if( isdigit( s->peek ) ) {
sym = get_int( s );
if( s->debug ) {
char buf[MAX_TMP_LEN];
char buf2[MAX_TMP_LEN];
buf[0] = '\0';
strcat( buf, "SCANNER(NUMBER," );
inttohex( sym.data.n, buf2 );
strcat( buf, buf2 );
strcat( buf, ")" );
print( buf );
}
return sym;
} else if( isalpha( s->peek ) ) {
sym = get_ident_or_label( s );
if( s->debug ) {
char buf[MAX_TMP_LEN];
buf[0] = '\0';
if( sym.sym == S_ident ) {
strcat( buf, "SCANNER(IDENT," );
} else if( sym.sym == S_label ) {
strcat( buf, "SCANNER(LABEL," );
} else {
strcat( buf, "SCANNER(<unknown>," );
}
strcat( buf, sym.data.s );
strcat( buf, ")" );
print( buf );
}
return sym;
} else if( s->peek == '\n' ) {
sym.sym = S_newline;
if( s->debug ) {
print( "SCANNER(NEWLINE)" );
}
s->peek = ' ';
return sym;
} else if( s->peek == ';' ) {
sym.sym = S_comment;
if( s->debug ) {
print( "SCANNER(COMMENT)" );
}
s->peek = ' ';
return sym;
} else {
sym.sym = S_token;
sym.tag = s->peek;
s->peek = ' ';
if( s->debug ) {
char buf[MAX_TMP_LEN];
char buf2[MAX_TMP_LEN];
buf[0] = '\0';
strcat( buf, "SCANNER(TOKEN," );
inttohex( sym.tag, buf2 );
strcat( buf, buf2 );
strcat( buf, ")" );
print( buf );
}
return sym;
}
return sym;
}
void scanner_debug( Scanner *s, int enable )
{
s->debug = enable;
if( s->debug ) {
print( "SCANNER DEBUGGING ENABLED" );
}
}
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