/
MOO-1.8.0p5/
/******************************************************************************
  Copyright (c) 1992, 1995, 1996 Xerox Corporation.  All rights reserved.
  Portions of this code were written by Stephen White, aka ghond.
  Use and copying of this software and preparation of derivative works based
  upon this software are permitted.  Any distribution of this software or
  derivative works must comply with all applicable United States export
  control laws.  This software is made available AS IS, and Xerox Corporation
  makes no warranty about the software, its performance or its conformity to
  any specification.  Any person obtaining a copy of this software is requested
  to send their name and post office or electronic mail address to:
    Pavel Curtis
    Xerox PARC
    3333 Coyote Hill Rd.
    Palo Alto, CA 94304
    Pavel@Xerox.Com
 *****************************************************************************/

#ifndef AST_h
#define AST_h 1

#include "config.h"
#include "parser.h"
#include "structures.h"
#include "sym_table.h"

typedef struct Expr 	  Expr;
typedef struct Arg_List   Arg_List;
typedef struct Stmt 	  Stmt;
typedef struct Cond_Arm   Cond_Arm;
typedef struct Except_Arm Except_Arm;
typedef struct Scatter 	  Scatter;

struct Expr_Binary {
    Expr       	       *lhs, *rhs;
};

enum Arg_Kind {
    ARG_NORMAL, ARG_SPLICE
};

struct Arg_List {
    Arg_List	       *next;
    enum Arg_Kind	kind;
    Expr	       *expr;
};

enum Scatter_Kind {
    SCAT_REQUIRED, SCAT_OPTIONAL, SCAT_REST
};

struct Scatter {
    Scatter	       *next;
    enum Scatter_Kind	kind;
    int			id;
    Expr	       *expr;
    /* These fields for convenience during code generation and decompiling */
    int			label, next_label;
};

struct Expr_Call {
    unsigned           func;
    Arg_List	       *args;
};

struct Expr_Verb {
    Expr	       *obj, *verb;
    Arg_List	       *args;
};

struct Expr_Range {
    Expr	       *base, *from, *to;
};

struct Expr_Cond {
    Expr	       *condition, *consequent, *alternate;
};

struct Expr_Catch {
    Expr	       *try;
    Arg_List	       *codes;
    Expr	       *except;
};

enum Expr_Kind {
    EXPR_VAR, EXPR_ID,
    EXPR_PROP, EXPR_VERB,
    EXPR_INDEX, EXPR_RANGE,
    EXPR_ASGN, EXPR_CALL,
    EXPR_PLUS, EXPR_MINUS, EXPR_TIMES, EXPR_DIVIDE, EXPR_MOD, EXPR_EXP,
    EXPR_NEGATE,
    EXPR_AND, EXPR_OR, EXPR_NOT,
    EXPR_EQ, EXPR_NE, EXPR_LT, EXPR_LE, EXPR_GT, EXPR_GE,
    EXPR_IN, EXPR_LIST, EXPR_COND,
    EXPR_CATCH, EXPR_LENGTH, EXPR_SCATTER,
    SizeOf_Expr_Kind /* The last element is also the number of elements... */
};

union Expr_Data {
    Var			var;
    int			id;
    struct Expr_Binary	bin;
    struct Expr_Call	call;
    struct Expr_Verb	verb;
    struct Expr_Range	range;
    struct Expr_Cond	cond;
    struct Expr_Catch	catch;
    Expr	       *expr;
    Arg_List	       *list;
    Scatter	       *scatter;
};

struct Expr {
    enum Expr_Kind	kind;
    union Expr_Data	e;
};

struct Cond_Arm {
    Cond_Arm           *next;
    Expr	       *condition;
    Stmt	       *stmt;
};

struct Except_Arm {
    Except_Arm	       *next;
    int			id;
    Arg_List	       *codes;
    Stmt	       *stmt;
    /* This field is for convenience during code generation and decompiling */
    int			label;
};

struct Stmt_Cond {
    Cond_Arm	       *arms;
    Stmt	       *otherwise;
};

struct Stmt_List {
    int			id;
    Expr	       *expr;
    Stmt	       *body;
};

struct Stmt_Range {
    int			id;
    Expr	       *from, *to;
    Stmt	       *body;
};

struct Stmt_Loop {
    int			id;
    Expr	       *condition;
    Stmt	       *body;
};

struct Stmt_Fork {
    int			id;
    Expr	       *time;
    Stmt	       *body;
};

struct Stmt_Catch {
    Stmt	       *body;
    Except_Arm	       *excepts;
};

struct Stmt_Finally {
    Stmt	       *body;
    Stmt	       *handler;
};

enum Stmt_Kind {
    STMT_COND, STMT_LIST, STMT_RANGE, STMT_WHILE, STMT_FORK, STMT_EXPR,
    STMT_RETURN, STMT_TRY_EXCEPT, STMT_TRY_FINALLY, STMT_BREAK, STMT_CONTINUE
};

union Stmt_Data {
    struct Stmt_Cond	cond;
    struct Stmt_List	list;
    struct Stmt_Range	range;
    struct Stmt_Loop	loop;
    struct Stmt_Fork	fork;
    struct Stmt_Catch	catch;
    struct Stmt_Finally	finally;
    Expr	       *expr;
    int			exit;
};

struct Stmt {
    Stmt	       *next;
    enum Stmt_Kind	kind;
    union Stmt_Data	s;
};
    

extern void	begin_code_allocation(void);
extern void	end_code_allocation(int);

extern Stmt		*alloc_stmt(enum Stmt_Kind);
extern Cond_Arm		*alloc_cond_arm(Expr *, Stmt *);
extern Expr		*alloc_expr(enum Expr_Kind);
extern Expr		*alloc_var(var_type);
extern Expr		*alloc_binary(enum Expr_Kind, Expr *, Expr *);
extern Expr		*alloc_verb(Expr *, Expr *, Arg_List *);
extern Arg_List		*alloc_arg_list(enum Arg_Kind, Expr *);
extern Except_Arm	*alloc_except(int, Arg_List *, Stmt *);
extern Scatter	       	*alloc_scatter(enum Scatter_Kind, int, Expr *);
extern char		*alloc_string(const char *);
extern double	       	*alloc_float(double);

extern void	dealloc_node(void *);
extern void	dealloc_string(char *);
extern void     free_stmt(Stmt *);

#endif /* !AST_h */

/* $Log: ast.h,v $
 * Revision 2.3  1996/02/08  05:59:43  pavel
 * Updated copyright notice for 1996.  Added exponentiation expression, named
 * WHILE loops, BREAK and CONTINUE statements, support for floating-point.
 * Release 1.8.0beta1.
 *
 * Revision 2.2  1996/01/16  07:13:43  pavel
 * Add support for scattering assignment.  Release 1.8.0alpha6.
 *
 * Revision 2.1  1995/12/31  03:14:38  pavel
 * Added EXPR_LENGTH.  Release 1.8.0alpha4.
 *
 * Revision 2.0  1995/11/30  04:50:19  pavel
 * New baseline version, corresponding to release 1.8.0alpha1.
 *
 * Revision 1.8  1992/10/23  23:03:47  pavel
 * Added copyright notice.
 *
 * Revision 1.7  1992/10/21  03:02:35  pavel
 * Converted to use new automatic configuration system.
 *
 * Revision 1.6  1992/08/31  22:21:43  pjames
 * Changed some `char *'s to `const char *'
 *
 * Revision 1.5  1992/08/28  23:13:36  pjames
 * Added ASGN_RANGE to assignment type enumeration.
 * Added range arm to assigment union.
 *
 * Revision 1.4  1992/08/14  00:15:28  pavel
 * Removed trailing comma in an enumeration.
 *
 * Revision 1.3  1992/08/14  00:01:11  pavel
 * Converted to a typedef of `var_type' = `enum var_type'.
 *
 * Revision 1.2  1992/07/30  21:21:21  pjames
 * Removed max_stack from AST structures.
 *
 * Revision 1.1  1992/07/20  23:23:12  pavel
 * Initial RCS-controlled version.
 */