/*    parser.h
 *
 *    Copyright (c) 2006, 2007, 2009, 2010, 2011 Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 * 
 * This file defines the layout of the parser object used by the parser
 * and lexer (perly.c, toke.c).
 */
#define YYEMPTY         (-2)
typedef struct {
    YYSTYPE val;    /* semantic value */
    short   state;
    I32     savestack_ix;       /* size of savestack at this state */
    CV      *compcv; /* value of PL_compcv when this value was created */
#ifdef DEBUGGING
    const char  *name; /* token/rule name for -Dpv */
#endif
} yy_stack_frame;
/* Fields that need to be shared with (i.e., visible to) inner lex-
   ing scopes. */
typedef struct yy_lexshared {
    struct yy_lexshared *ls_prev;
    SV                  *ls_linestr;    /* mirrors PL_parser->linestr */
    char                *ls_bufptr;     /* mirrors PL_parser->bufptr */
    char                *re_eval_start; /* start of "(?{..." text */
    SV                  *re_eval_str;   /* "(?{...})" text */
} LEXSHARED;
typedef struct yy_parser {
    /* parser state */
    struct yy_parser *old_parser; /* previous value of PL_parser */
    YYSTYPE         yylval;     /* value of lookahead symbol, set by yylex() */
    int             yychar;     /* The lookahead symbol.  */
    /* Number of tokens to shift before error messages enabled.  */
    int             yyerrstatus;
    yy_stack_frame  *stack;     /* base of stack */
    yy_stack_frame  *stack_max1;/* (top-1)th element of allocated stack */
    yy_stack_frame  *ps;        /* current stack frame */
    int             yylen;      /* length of active reduction */
    /* lexer state */
    I32         lex_formbrack;  /* bracket count at outer format level */
    I32         lex_brackets;   /* square and curly bracket count */
    I32         lex_casemods;   /* casemod count */
    char        *lex_brackstack;/* what kind of brackets to pop */
    char        *lex_casestack; /* what kind of case mods in effect */
    U8          lex_defer;      /* state after determined token */
    U8          lex_dojoin;     /* doing an array interpolation
                                   1 = @{...}  2 = ->@ */
    U8          expect;         /* how to interpret ambiguous tokens */
    bool        preambled;
    bool        sub_no_recover; /* can't recover from a sublex error */
    U8          sub_error_count; /* the number of errors before sublexing */
    OP          *lex_inpat;     /* in pattern $) and $| are special */
    OP          *lex_op;        /* extra info to pass back on op */
    SV          *lex_repl;      /* runtime replacement from s/// */
    U16         lex_inwhat;     /* what kind of quoting are we in */
    OPCODE      last_lop_op;    /* last named list or unary operator */
    I32         lex_starts;     /* how many interps done on level */
    SV          *lex_stuff;     /* runtime pattern from m// or s/// */
    I32         multi_start;    /* 1st line of multi-line string */
    I32         multi_end;      /* last line of multi-line string */
    UV          multi_open;     /* delimiter code point of said string */
    UV          multi_close;    /* delimiter code point of said string */
    bool        lex_re_reparsing; /* we're doing G_RE_REPARSING */
    U8          lex_super_state;/* lexer state to save */
    U16         lex_sub_inwhat; /* "lex_inwhat" to use in sublex_push */
    I32         lex_allbrackets;/* (), [], {}, ?: bracket count */
    OP          *lex_sub_op;    /* current op in y/// or pattern */
    SV          *lex_sub_repl;  /* repl of s/// used in sublex_push */
    LEXSHARED   *lex_shared;
    SV          *linestr;       /* current chunk of src text */
    char        *bufptr;        /* carries the cursor (current parsing
                                   position) from one invocation of yylex
                                   to the next */
    char        *oldbufptr;     /* in yylex, beginning of current token */
    char        *oldoldbufptr;  /* in yylex, beginning of previous token */
    char        *bufend;        
    char        *linestart;     /* beginning of most recently read line */
    char        *last_uni;      /* position of last named-unary op */
    char        *last_lop;      /* position of last list operator */
    /* copline is used to pass a specific line number to newSTATEOP.  It
       is a one-time line number, as newSTATEOP invalidates it (sets it to
       NOLINE) after using it.  The purpose of this is to report line num-
       bers in multiline constructs using the number of the first line. */
    line_t      copline;
    U16         in_my;          /* we're compiling a "my"/"our" declaration */
    U8          lex_state;      /* next token is determined */
    U8          error_count;    /* how many compile errors so far, max 10 */
    HV          *in_my_stash;   /* declared class of this "my" declaration */
    PerlIO      *rsfp;          /* current source file pointer */
    AV          *rsfp_filters;  /* holds chain of active source filters */
    YYSTYPE     nextval[5];     /* value of next token, if any */
    I32         nexttype[5];    /* type of next token */
    U8          nexttoke;
    U8          form_lex_state; /* remember lex_state when parsing fmt */
    U8          lex_fakeeof;    /* precedence at which to fake EOF */
    U8          lex_flags;
    COP         *saved_curcop;  /* the previous PL_curcop */
    char        tokenbuf[256];
    line_t      herelines;      /* number of lines in here-doc */
    line_t      preambling;     /* line # when processing $ENV{PERL5DB} */
    /* these are valid while parsing a subroutine signature */
    UV          sig_elems;      /* number of signature elements seen so far */
    UV          sig_optelems;   /* number of optional signature elems seen */
    char        sig_slurpy;     /* the sigil of the slurpy var (or null) */
    bool        sig_seen;       /* the currently parsing sub has a signature */
    bool        recheck_utf8_validity;
    PERL_BITFIELD16     in_pod:1;      /* lexer is within a =pod section */
    PERL_BITFIELD16     filtered:1;    /* source filters in evalbytes */
    PERL_BITFIELD16     saw_infix_sigil:1; /* saw & or * or % operator */
    PERL_BITFIELD16     parsed_sub:1;  /* last thing parsed was a sub */
} yy_parser;
/* flags for lexer API */
#define LEX_STUFF_UTF8          0x00000001
#define LEX_KEEP_PREVIOUS       0x00000002
#ifdef PERL_CORE
# define LEX_START_SAME_FILTER  0x00000001
# define LEX_IGNORE_UTF8_HINTS  0x00000002
# define LEX_EVALBYTES          0x00000004
# define LEX_START_COPIED       0x00000008
# define LEX_DONT_CLOSE_RSFP    0x00000010
# define LEX_START_FLAGS \
        (LEX_START_SAME_FILTER|LEX_START_COPIED \
        |LEX_IGNORE_UTF8_HINTS|LEX_EVALBYTES|LEX_DONT_CLOSE_RSFP)
#endif
/* flags for parser API */
#define PARSE_OPTIONAL          0x00000001
/* values for lex_fakeeof */
enum {
    LEX_FAKEEOF_NEVER,      /* don't fake EOF */
    LEX_FAKEEOF_CLOSING,    /* fake EOF at unmatched closing punctuation */
    LEX_FAKEEOF_NONEXPR,    /* ... and at token that can't be in expression */
    LEX_FAKEEOF_LOWLOGIC,   /* ... and at low-precedence logic operator */
    LEX_FAKEEOF_COMMA,      /* ... and at comma */
    LEX_FAKEEOF_ASSIGN,     /* ... and at assignment operator */
    LEX_FAKEEOF_IFELSE,     /* ... and at ?: operator */
    LEX_FAKEEOF_RANGE,      /* ... and at range operator */
    LEX_FAKEEOF_LOGIC,      /* ... and at logic operator */
    LEX_FAKEEOF_BITWISE,    /* ... and at bitwise operator */
    LEX_FAKEEOF_COMPARE,    /* ... and at comparison operator */
    LEX_FAKEEOF_MAX
};
/*
 * ex: set ts=8 sts=4 sw=4 et:
 */