/* Abstract syntax tree
 *
 * SOFTWARE RIGHTS
 *
 * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
 * Set (PCCTS) -- PCCTS is in the public domain.  An individual or
 * company may do whatever they wish with source code distributed with
 * PCCTS or the code generated by PCCTS, including the incorporation of
 * PCCTS, or its output, into commerical software.
 * 
 * We encourage users to develop software with PCCTS.  However, we do ask
 * that credit is given to us for developing PCCTS.  By "credit",
 * we mean that if you incorporate our source code into one of your
 * programs (commercial product, research project, or otherwise) that you
 * acknowledge this fact somewhere in the documentation, research report,
 * etc...  If you like PCCTS and have developed a nice tool with the
 * output, please mention that you developed it using PCCTS.  In
 * addition, we ask that this header remain intact in our source code.
 * As long as these guidelines are kept, we expect to continue enhancing
 * this system and expect to make other tools available as they are
 * completed.
 *
 * ANTLR 1.33
 * Terence Parr
 * Parr Research Corporation
 * with Purdue University and AHPCRC, University of Minnesota
 * 1989-1995
 */

#ifndef PCCTSAST_H
#define PCCTSAST_H

#include <stdio.h>
#include <stdlib.h>
#include "config.h"
//class SList;

#define StringScanMaxText	50
#define MaxTreeStackDepth	400

typedef struct stringlexer {
			signed int c;
			char *input;
			char *p;
			char text[StringScanMaxText];
		} StringLexer;

/* Define the structures needed for ast_scan() */
typedef struct stringparser {
			int token;
			StringLexer *lexer;
			int num_labels;
		} StringParser;

typedef struct _scanast {
            struct _scanast *_right, *_down;
            int _token;
			int label_num;
			int type() { return _token; }
			struct _scanast *right() { return _right; }
			struct _scanast *down() { return _down; }
        } ScanAST;

#define VALID_SCAN_TOKEN(t)		(t>=__LPAREN && t<=__PERIOD)

class PCCTS_AST {
protected:
	static char *scan_token_tbl[];
	enum {
	__LPAREN=1,
	__RPAREN=2,
	__PERCENT=3,
	__INT=4,
	__COLON=5,
	__POUND=6,
	__PERIOD=7,
	__StringScanEOF=-1};

protected:
	char *scan_token_str(int t);
	void stringlexer_init(StringLexer *scanner, char *input);
	void stringparser_init(StringParser *, StringLexer *);
	ScanAST *stringparser_parse_scanast(char *templ, int *n);
	ScanAST *stringparser_parse_tree(StringParser *parser);
	ScanAST *stringparser_parse_element(StringParser *parser);
	void stringscan_advance(StringLexer *scanner);
	int stringscan_gettok(StringLexer *scanner);
	void _push(PCCTS_AST **st, int *sp, PCCTS_AST *e);
	PCCTS_AST *_pop(PCCTS_AST **st, int *sp);
	int match_partial(PCCTS_AST *t, PCCTS_AST *u);
	int scanmatch(ScanAST *t, PCCTS_AST **labels[], int *n);
	void scanast_free(ScanAST *t);
	ScanAST *new_scanast(int tok);
	void stringparser_match(StringParser *parser, int type);
	virtual PCCTS_AST *deepCopyBushy();

public:
	PCCTS_AST()	{;}
	virtual ~PCCTS_AST() {;}

	/* This group must be defined for SORCERER to work correctly */
	virtual PCCTS_AST *right() = 0;
	virtual PCCTS_AST *down() = 0;
	virtual void setRight(PCCTS_AST *t) = 0;
	virtual void setDown(PCCTS_AST *t) = 0;
// we define these so ANTLR doesn't have to
	virtual int type() { return 0; }
	virtual void setType(int t) {;}
	virtual PCCTS_AST *shallowCopy() {panic("no shallowCopy() defined"); return NULL;}

	/* These are not needed by ANTLR, but are support functions */
	virtual PCCTS_AST *deepCopy();	// used by SORCERER in transform mode
	virtual void addChild(PCCTS_AST *t);
	virtual void lisp_action(FILE *f) {;}
	virtual void lisp(FILE *f);
	static PCCTS_AST *make(PCCTS_AST *rt, ...);
	virtual PCCTS_AST *ast_find_all(PCCTS_AST *u, PCCTS_AST **cursor);
	virtual int match(PCCTS_AST *u);
	virtual void insert_after(PCCTS_AST *b);
	virtual void append(PCCTS_AST *b);
	virtual PCCTS_AST *tail();
	virtual PCCTS_AST *bottom();
	static  PCCTS_AST *cut_between(PCCTS_AST *a, PCCTS_AST *b);
//	virtual SList *to_slist();
	virtual void tfree();
	int ast_scan(char *templ, ...);
	virtual int nsiblings();
	virtual PCCTS_AST *sibling_index(int i);

	void require(int e,char *err){ if ( !e ) panic(err); }
	virtual void panic(char *err)
		{ fprintf(stderr, "PCCTS_AST: %s\n", err); exit(PCCTS_EXIT_FAILURE); }
};

#endif /* PCCTSAST_H */