/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

#ifndef jsscan_h___
#define jsscan_h___
/*
 * JS lexical scanner interface.
 */
#include <stddef.h>
#ifdef JSFILE
#include <stdio.h>
#endif
#include "jsopcode.h"
#include "jsprvtd.h"
#include "jspubtd.h"

#ifdef JSD_LOWLEVEL_SOURCE
#include "jsdebug.h"
#endif

PR_BEGIN_EXTERN_C

typedef enum JSTokenType {
    TOK_ERROR = -1,                     /* well-known as the only code < EOF */
    TOK_EOF = 0,                        /* end of file */
    TOK_EOL = 1,                        /* end of line */
    TOK_SEMI = 2,                       /* semicolon */
    TOK_LB = 3, TOK_RB = 4,             /* left and right brackets */
    TOK_LC = 5, TOK_RC = 6,             /* left and right curlies (braces) */
    TOK_LP = 7, TOK_RP = 8,             /* left and right parentheses */
    TOK_COMMA = 9,                      /* comma operator */
    TOK_ASSIGN = 10,                    /* assignment ops (= += -= etc.) */
    TOK_HOOK = 11, TOK_COLON = 12,      /* conditional (?:) */
    TOK_OR = 13,                        /* logical or (||) */
    TOK_AND = 14,                       /* logical and (&&) */
    TOK_BITOR = 15,                     /* bitwise-or (|) */
    TOK_BITXOR = 16,                    /* bitwise-xor (^) */
    TOK_BITAND = 17,                    /* bitwise-and (&) */
    TOK_EQOP = 18,                      /* equality ops (== !=) */
    TOK_RELOP = 19,                     /* relational ops (< <= > >=) */
    TOK_SHOP = 20,                      /* shift ops (<< >> >>>) */
    TOK_PLUS = 21,                      /* plus */
    TOK_MINUS = 22,                     /* minus */
    TOK_STAR = 23, TOK_DIVOP = 24,      /* multiply/divide ops (* / %) */
    TOK_UNARYOP = 25,                   /* unary prefix operator */
    TOK_INC = 26, TOK_DEC = 27,         /* increment/decrement (++ --) */
    TOK_DOT = 28,                       /* member operator (.) */
    TOK_NAME = 29,                      /* identifier */
    TOK_NUMBER = 30,                    /* numeric constant */
    TOK_STRING = 31,                    /* string constant */
    TOK_OBJECT = 32,                    /* RegExp or other object constant */
    TOK_PRIMARY = 33,                   /* true, false, null, this, super */
    TOK_FUNCTION = 34,                  /* function keyword */
    TOK_EXPORT = 35,                    /* export keyword */
    TOK_IMPORT = 36,                    /* import keyword */
    TOK_IF = 37,                        /* if keyword */
    TOK_ELSE = 38,                      /* else keyword */
    TOK_SWITCH = 39,                    /* switch keyword */
    TOK_CASE = 40,                      /* case keyword */
    TOK_DEFAULT = 41,                   /* default keyword */
    TOK_WHILE = 42,                     /* while keyword */
    TOK_DO = 43,                        /* do keyword */
    TOK_FOR = 44,                       /* for keyword */
    TOK_BREAK = 45,                     /* break keyword */
    TOK_CONTINUE = 46,                  /* continue keyword */
    TOK_IN = 47,                        /* in keyword */
    TOK_VAR = 48,                       /* var keyword */
    TOK_WITH = 49,                      /* with keyword */
    TOK_RETURN = 50,                    /* return keyword */
    TOK_NEW = 51,                       /* new keyword */
    TOK_DELETE = 52,                    /* delete keyword */
    TOK_DEFSHARP = 53,                  /* #n= for object/array initializers */
    TOK_USESHARP = 54,                  /* #n# for object/array initializers */
    TOK_TRY = 55,                       /* try keyword */
    TOK_CATCH = 56,                     /* catch keyword */
    TOK_FINALLY = 57,                   /* finally keyword */
    TOK_THROW = 58,                     /* throw keyword */
    TOK_INSTANCEOF = 59,                /* instanceof keyword */
    TOK_RESERVED,                       /* reserved keywords */
    TOK_LIMIT                           /* domain size */
} JSTokenType;

#define IS_PRIMARY_TOKEN(tt) \
    ((uintN)((tt) - TOK_NAME) <= (uintN)(TOK_PRIMARY - TOK_NAME))

struct JSTokenPtr {
    uint16              index;          /* index of char in physical line */
    uint16              lineno;         /* physical line number */
};

struct JSTokenPos {
    JSTokenPtr          begin;          /* first character and line of token */
    JSTokenPtr          end;            /* index 1 past last char, last line */
};

struct JSToken {
    JSTokenType         type;           /* char value or above enumerator */
    JSTokenPos          pos;            /* token position in file */
    jschar              *ptr;           /* beginning of token in line buffer */
    union {
        struct {
	    JSOp        op;             /* operator, for minimal parser */
	    JSAtom      *atom;          /* atom table entry */
        } s;
        jsdouble        dval;           /* floating point number */
    } u;
};

#define t_op            u.s.op
#define t_atom          u.s.atom
#define t_dval          u.dval

typedef struct JSTokenBuf {
    jschar              *base;          /* base of line or stream buffer */
    jschar              *limit;         /* limit for quick bounds check */
    jschar              *ptr;           /* next char to get, or slot to use */
} JSTokenBuf;

#define JS_LINE_LIMIT   256             /* logical line buffer size limit --
                                           physical line length is unlimited */

struct JSTokenStream {
    JSToken             token;          /* last token scanned */
    JSToken             pushback;       /* pushed-back already-scanned token */
    uintN               lineno;         /* current line number */
    uintN               ungetpos;       /* next free char slot in ungetbuf */
    jschar              ungetbuf[4];    /* at most 4, for \uXXXX lookahead */
    uintN               flags;          /* flags -- see below */
    ptrdiff_t           linelen;        /* physical linebuf segment length */
    ptrdiff_t           linepos;        /* linebuf offset in physical line */
    JSTokenBuf          linebuf;        /* line buffer for diagnostics */
    JSTokenBuf          userbuf;        /* user input buffer if !file */
    JSTokenBuf          tokenbuf;       /* current token string buffer */
    const char          *filename;      /* input filename or null */
#ifdef JSFILE
    FILE                *file;          /* stdio stream if reading from file */
#endif
    JSPrincipals        *principals;    /* principals associated with given input */
#ifdef JSD_LOWLEVEL_SOURCE
    JSDContext          *jsdc;          /* used to cram source into debugger */
    JSDSourceText       *jsdsrc;        /* used to cram source into debugger */
#endif
};

/* JSTokenStream flags */
#define TSF_ERROR       0x01            /* fatal error while scanning */
#define TSF_EOF         0x02            /* hit end of file */
#define TSF_NEWLINES    0x04            /* tokenize newlines */
#define TSF_REGEXP      0x08            /* looking for a regular expression */
#define TSF_INTERACTIVE 0x10            /* interactive parsing mode */
#define TSF_NLFLAG      0x20            /* last linebuf ended with \n */
#define TSF_CRFLAG      0x40            /* linebuf would have ended with \r */

/*
 * At most one non-EOF token can be pushed back onto a TokenStream between
 * Get or successful Match operations.  These macros manipulate the pushback
 * token to clear it when changing scanning modes (upon initialzation, after
 * errors, or between newline-sensitive and insensitive states).
 */
#define CLEAR_PUSHBACK(ts)  ((ts)->pushback.type = TOK_EOF)
#define SCAN_NEWLINES(ts)   ((ts)->flags |= TSF_NEWLINES)
#define HIDE_NEWLINES(ts)                                                     \
    PR_BEGIN_MACRO                                                            \
	(ts)->flags &= ~TSF_NEWLINES;                                         \
	if ((ts)->pushback.type == TOK_EOL)                                   \
	    (ts)->pushback.type = TOK_EOF;                                    \
    PR_END_MACRO

/* Clear ts member that might point above a released cx->tempPool mark. */
#define RESET_TOKENBUF(ts)  ((ts)->tokenbuf.base = (ts)->tokenbuf.limit = NULL)

/*
 * Create a new token stream, either from an input buffer or from a file.
 * Return null on file-open or memory-allocation failure.
 *
 * NB: All of js_New{,Buffer,File}TokenStream() return a pointer to transient
 * memory in the current context's temp pool.  This memory is deallocated via
 * PR_ARENA_RELEASE() after parsing is finished.
 */
extern JSTokenStream *
js_NewTokenStream(JSContext *cx, const jschar *base, size_t length,
		  const char *filename, uintN lineno, JSPrincipals *principals);

extern JS_FRIEND_API(JSTokenStream *)
js_NewBufferTokenStream(JSContext *cx, const jschar *base, size_t length);

#ifdef JSFILE
extern JS_FRIEND_API(JSTokenStream *)
js_NewFileTokenStream(JSContext *cx, const char *filename, FILE *defaultfp);
#endif

extern JS_FRIEND_API(JSBool)
js_CloseTokenStream(JSContext *cx, JSTokenStream *ts);

/*
 * Initialize the scanner, installing JS keywords into cx's global scope.
 */
extern JSBool
js_InitScanner(JSContext *cx);

/*
 * Friend-exported API entry point to call a mapping function on each reserved
 * identifier in the scanner's keyword table.
 */
extern JS_FRIEND_API(void)
js_MapKeywords(void (*mapfun)(const char *));

/*
 * Report an error found while scanning ts to a window or other output device
 * associated with cx.
 */
extern void
js_ReportCompileError(JSContext *cx, JSTokenStream *ts, const char *format,
		      ...);

/*
 * Look ahead one token and return its type.
 */
extern JSTokenType
js_PeekToken(JSContext *cx, JSTokenStream *ts);

extern JSTokenType
js_PeekTokenSameLine(JSContext *cx, JSTokenStream *ts);

/*
 * Get the next token from ts.
 */
extern JSTokenType
js_GetToken(JSContext *cx, JSTokenStream *ts);

/*
 * Push back the last scanned token onto ts.
 */
extern void
js_UngetToken(JSTokenStream *ts);

/*
 * Get the next token from ts if its type is tt.
 */
extern JSBool
js_MatchToken(JSContext *cx, JSTokenStream *ts, JSTokenType tt);

PR_END_EXTERN_C

#endif /* jsscan_h___ */
