/*
 *	CDECL.Y	-  Translate 'C' declarations to english
 *	Phil Budne, May 12, 1984
 */

/*
 *	The purpose of this program is to translate large obtuse
 *	C language declarations into english.  It was inspired by
 *	the article 'TYPE SYNTAX IN THE LANGUAGE "C"; an object
 *	lesson in syntactic innovation' by Bruce Anderson.
 *
 *	While the article and the need for such a program such as this
 *	might tend to deride the capabilities of 'C', it must be
 *	duly noted that this program would have taken more than
 *	the two hours it did to write it without the avaiablilty of
 *	tools such as 'C' and 'YACC'
 */

%{
# include <stdio.h>
# include <ctype.h>
/* # define YYDEBUG 1 */
%}

%union {
	char *sval;
}

%token	<sval>	ID
%token	'('	')'	'['	']'	'*'	';'

%%

start:	ID dclr ';'		{ printf("%s\n",$1); }

dclr:	'*' dclr		{ printf("ref "); }
	| dclr '(' ')'		{ printf("proc() "); }
	| dclr '[' ']'		{ printf("array of "); }
	| ID			{ printf("%s: ",$1); }
	| '(' dclr ')'

%%

char strbuf[80];
char *strptr;
extern char *malloc();

main() {
	puts("Input a C declarator: ");
	gets(strbuf);
	strptr = &strbuf;
	yyparse();
}

# define NEXT c= *strptr++;if(c==0)return(0)

yylex() {
	register char c;

	NEXT;
	while( c == ' ' || c == '\t' )
		NEXT;

	if( isalpha(c) ) {
		register char *idp, *save;

		idp = save = malloc(20);
		*idp++ = c;
		c = *strptr++;
		while( c != 0 && isalnum(c) || c == '_' ) {
			*idp++ = c; /* store character */
			c = *strptr++; /* advance pointer */
		}
		*idp = 0;	/* terminate token */
		strptr--;	/* backup over terminator */
		yylval.sval = save; /* return address of token */
		return( ID );	/* say what kind of token */
	}
		
	switch(	c ) {
	case '*':
	case '(':
	case ')':
	case '[':
	case ']':
	case ';':
		return( c );
	}

	return( -1 );
}


yyermsg(s)
char *s;
{
	printf("?%s\n",s);
}