initial checkin

1 files changed, 180 insertions, 0 deletions

diff --git a/old/parser.c b/old/parser.c
new file mode 100644
index 0000000..79a7905
--- /dev/null
+++ b/old/parser.c
@@ -0,0 +1,180 @@
+#include <stdio.h>
+#include <ctype.h>
+
+#define MAXLEN 80
+
+typedef enum {
+	undef,
+	eof,
+	error,
+	identifier,
+	literal,
+	dot,
+	eql,
+	lparen,
+	rparen,
+	lbrak,
+	rbrak,
+	lbrace,
+	rbrace,
+	bar
+} Sym;
+
+typedef struct {
+	Sym sym;
+	char value[MAXLEN];
+} Symbol;
+
+typedef struct {
+	int line;
+	int col;
+	FILE *f;
+} Scanner;
+
+static int get_char( Scanner *scan ) {
+	int c = getc( scan->f );
+	scan->col++;
+	if( c == '\n' ) {
+		scan->line++;
+		scan->col = 1;
+	}
+	return c;
+}
+
+static void unget_char( Scanner *scan, int c ) {
+	ungetc( c, scan->f );
+	scan->col--;
+}
+
+static Symbol skip_blanks( Scanner *scan ) {
+	int c;
+	Symbol s;
+
+	while( ( c = get_char( scan ) ) != EOF && iscntrl( c ) || ( c == ' ' ) );
+
+	if( c == EOF ) {
+		s.sym = eof;
+		return s;
+	}
+
+	unget_char( scan, c );
+
+	s.sym = undef;
+	return s;
+}
+
+static int is_letter( char c ) {
+	return( ( c >= 'A' && c <= 'Z' ) || ( c >= 'a' && c <= 'z' ) );
+}
+
+static int is_digit( char c ) {
+	return( c >= '0' && c <= '9' );
+}
+
+static Symbol get_sym( Scanner *scan ) {
+	int c;
+	Symbol s;
+	int i;
+
+	s.sym = undef;
+
+	s = skip_blanks( scan );
+	if( s.sym == eof ) return s;
+
+	c = get_char( scan );
+	if( c == EOF ) {
+		s.sym = EOF;
+		return s;
+	}
+	unget_char( scan, c );
+
+	if( is_letter( c ) ) {
+		i = 0;
+		s.sym = identifier;
+		while( ( c = get_char( scan ) ) != EOF && is_letter( c ) ) {
+			s.value[i++] = c;
+		}
+		s.value[i] = '\0';
+		printf( "(%d:%d): ident '%s'\n", scan->line, scan->col, s.value );
+	} else if( c == '\"' ) {
+		int escaped = 0;
+		i = 0;
+		s.sym = literal;
+		(void)get_char( scan ); /* skip first quote */
+		while( ( c = get_char( scan ) ) != EOF && c != '\"' || escaped ) {
+			if( c == '\\' ) {
+				escaped = 1;
+			} else {
+				s.value[i++] = c;
+				escaped = 0;
+			}
+		}
+		s.value[i] = '\0';
+		/* ensure we end in a quote */
+		if( c != '\"' ) {
+			fprintf( stderr, "ERROR(%d:%d): Unbalanced quote after literal '%s'\n",
+				scan->line, scan->col, s.value );
+			s.sym = error;
+			return s;
+		}
+		printf( "(%d:%d): literal '%s'\n", scan->line, scan->col, s.value );
+	} else if( c == '=' ) {
+		c = get_char( scan );
+		s.sym = eql;
+	} else if( c == '(' ) {
+		c = get_char( scan );
+		s.sym = lparen;
+	} else if( c == ')' ) {
+		c = get_char( scan );
+		s.sym = rparen;
+	} else if( c == '[' ) {
+		c = get_char( scan );
+		s.sym = lbrak;
+	} else if( c == ']' ) {
+		c = get_char( scan );
+		s.sym = rbrak;
+	} else if( c == '{' ) {
+		c = get_char( scan );
+		s.sym = lbrace;
+	} else if( c == '}' ) {
+		c = get_char( scan );
+		s.sym = rbrace;
+	} else if( c == '|' ) {
+		c = get_char( scan );
+		s.sym = bar;
+	} else if( c == '.' ) {
+		c = get_char( scan );
+		s.sym = dot;
+	} else {
+		c = get_char( scan );
+		s.sym = error;
+	}
+
+	return s;
+}
+
+static Scanner init_scanner( FILE *f )
+{
+	Scanner s;
+
+	s.line = 1;
+	s.col = 1;
+	s.f = f;
+
+	return s;
+}
+
+int main( void )
+{
+	Symbol s;
+	Scanner scan;
+
+	scan = init_scanner( stdin );
+
+	do {
+		s = get_sym( &scan );
+		if( s.sym == eof ) continue;
+	} while( s.sym != eof );
+
+	return 0;
+}