From 5820c00c3459e366c39f8db0ac063c30005f0c12 Mon Sep 17 00:00:00 2001 From: solar Date: Wed, 23 Sep 2009 18:33:14 +0000 Subject: [PATCH] Rough draft implementation. --- functions/_PDCLIB/scan.c | 231 ++++++++++++++++++++++++++++----------- 1 file changed, 167 insertions(+), 64 deletions(-) diff --git a/functions/_PDCLIB/scan.c b/functions/_PDCLIB/scan.c index 523b0c8..c982610 100644 --- a/functions/_PDCLIB/scan.c +++ b/functions/_PDCLIB/scan.c @@ -10,7 +10,10 @@ #include #include #include +#include #include +#include +#include /* Using an integer's bits as flags for both the conversion flags and length modifiers. @@ -28,42 +31,24 @@ #define E_unsigned 1<<16 -#define MATCH_FAIL -1 -#define MATCH_ERROR -2 +#define ASSIGN( case_cond, type ) \ + case case_cond: \ + *( va_arg( status->arg, type * ) ) = (type)( value * sign ); \ + break -static int MATCH( int c, struct _PDCLIB_status_t * status ) + +static int GET( struct _PDCLIB_status_t * status ) { + ++(status->i); + ++(status->this); if ( status->stream != NULL ) { - if ( ! _PDCLIB_prepread( status->stream ) ) - { - return MATCH_ERROR; - } - if ( tolower( status->stream->buffer[ status->stream->bufidx ] ) == c ) - { - /* recycling parameter */ - c = getc( status->stream ); - } - else - { - return MATCH_FAIL; - } + return getc( status->stream ); } else { - if ( tolower( *(status->s) ) == c ) - { - /* recycling parameter */ - c = *((status->s)++); /* TODO: \0 */ - } - else - { - return MATCH_FAIL; - } + return *((status->s)++); } - ++(status->i); - ++(status->this); - return c; } @@ -84,12 +69,24 @@ static void UNGET( int c, struct _PDCLIB_status_t * status ) const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status ) { + /* generic input character */ + int rc; const char * orig_spec = spec; if ( *(++spec) == '%' ) { /* %% -> match single '%' */ - MATCH( *spec, status ); - return ++spec; + rc = GET( status ); + switch ( rc ) + { + case EOF: + /* matching failure */ + return NULL; + case '%': + return ++spec; + default: + UNGET( rc, status ); + break; + } } /* Initializing status structure */ status->flags = 0; @@ -166,6 +163,10 @@ const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status ) } /* Conversion specifier */ + + /* whether valid input had been parsed */ + bool value_parsed = false; + switch ( *spec ) { case 'd': @@ -196,13 +197,56 @@ const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status ) case 'A': break; case 'c': - /* TODO */ - break; + { + char * c = va_arg( status->arg, char * ); + if ( status->width == SIZE_MAX ) + { + status->width = 1; + } + while ( ( status->this < status->width ) && + ( ( rc = GET( status ) ) != EOF ) ) + { + *(c++) = rc; + value_parsed = true; + } + return value_parsed ? spec : NULL; + } case 's': - /* TODO */ - break; + { + char * c = va_arg( status->arg, char * ); + while ( ( status->this < status->width ) && + ( ( rc = GET( status ) ) != EOF ) ) + { + if ( isspace( rc ) ) + { + if ( value_parsed ) + { + *c = '\0'; + return spec; + } + else + { + --(status->this); + } + } + else + { + value_parsed = true; + *(c++) = rc; + } + } + /* width or input exhausted */ + if ( value_parsed ) + { + *c = '\0'; + return spec; + } + else + { + return NULL; + } + } case 'p': - /* TODO */ status->base = 16; status->flags |= E_unsigned; break; @@ -216,61 +260,120 @@ const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status ) /* No conversion specifier. Bad conversion. */ return orig_spec; } - bool zero = false; + if ( status->base != -1 ) { - bool value = false; - int rc; - if ( ( rc = MATCH( '0', status ) ) >= 0 ) + /* integer conversion */ + uintmax_t value = 0; + bool prefix_parsed = false; + int sign = 0; + while ( ( status->this < status->width ) && + ( ( rc = GET( status ) ) != EOF ) ) { - if ( ( rc = MATCH( 'x', status ) ) >= 0 ) + if ( ! sign ) { - if ( ( status->base == 0 ) || ( status->base == 16 ) ) + switch ( rc ) { - status->base = 16; - } - else - { - UNGET( rc, status ); - value = true; + case '-': + sign = -1; + break; + case '+': + sign = 1; + break; + default: + sign = 1; + UNGET( rc, status ); + break; } } - else if ( rc == MATCH_FAIL ) + else if ( ! prefix_parsed ) { - if ( status->base == 0 ) + prefix_parsed = true; + if ( rc != '0' ) { - status->base = 8; + if ( status->base == 0 ) + { + status->base = 10; + } + UNGET( rc, status ); } else { - value = true; + if ( ( status->this < status->width ) && + ( ( rc = GET( status ) ) != EOF ) ) + { + if ( tolower( rc ) == 'x' ) + { + if ( ( status->base == 0 ) || + ( status->base == 16 ) ) + { + status->base = 16; + } + else + { + UNGET( rc, status ); + value_parsed = true; + } + } + else + { + UNGET( rc, status ); + if ( status->base == 0 ) + { + status->base = 8; + } + value_parsed = true; + } + } } } else { - /* TODO: MATCH_ERROR */ + char * digitptr = memchr( _PDCLIB_digits, tolower( rc ), status->base ); + if ( digitptr == NULL ) + { + /* end of input item */ + break; + } + value *= status->base; + value += digitptr - _PDCLIB_digits; + value_parsed = true; } } - else if ( rc == MATCH_FAIL ) + /* width exceeded, EOF, read error, non-matching character */ + if ( ! value_parsed ) { - if ( status->base == 0 ) - { - status->base = 10; - } + /* matching error */ + return NULL; } - else + switch ( status->flags & ( E_char | E_short | E_long | E_llong | + E_intmax | E_size | E_ptrdiff | + E_unsigned ) ) { - /* TODO: MATCH_ERROR */ + ASSIGN( E_char, char ); + ASSIGN( E_char | E_unsigned, unsigned char ); + ASSIGN( E_short, short ); + ASSIGN( E_short | E_unsigned, unsigned short ); + ASSIGN( 0, int ); + ASSIGN( E_unsigned, unsigned int ); + ASSIGN( E_long, long ); + ASSIGN( E_long | E_unsigned, unsigned long ); + ASSIGN( E_llong, long long ); + ASSIGN( E_llong | E_unsigned, unsigned long long ); + ASSIGN( E_intmax, intmax_t ); + ASSIGN( E_intmax | E_unsigned, uintmax_t ); + ASSIGN( E_size, size_t ); + /* ASSIGN( E_size | E_unsigned, unsigned size_t ); */ + ASSIGN( E_ptrdiff, ptrdiff_t ); + /* ASSIGN( E_ptrdiff | E_unsigned, unsigned ptrdiff_t ); */ } - /* TODO: Integer conversion */ - } - else - { - /* TODO: Float conversions? */ + return spec; } + /* TODO: Floats. */ return NULL; } + #ifdef TEST #include <_PDCLIB_test.h> -- 2.40.0