/*      Id: eqn.h,v 1.1 2018/12/13 05:23:38 schwarze Exp  */
/*
* Copyright (c) 2011, 2014 Kristaps Dzonsons <[email protected]>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Public data types for eqn(7) syntax trees.
*/

enum    eqn_boxt {
       EQN_TEXT,       /* Text, e.g. number, variable, operator, ... */
       EQN_SUBEXPR,    /* Nested eqn(7) subexpression. */
       EQN_LIST,       /* List, for example in braces. */
       EQN_PILE,       /* Vertical pile. */
       EQN_MATRIX      /* List of columns. */
};

enum    eqn_fontt {
       EQNFONT_NONE = 0,
       EQNFONT_ROMAN,
       EQNFONT_BOLD,
       EQNFONT_FAT,
       EQNFONT_ITALIC,
       EQNFONT__MAX
};

enum    eqn_post {
       EQNPOS_NONE = 0,
       EQNPOS_SUP,
       EQNPOS_SUBSUP,
       EQNPOS_SUB,
       EQNPOS_TO,
       EQNPOS_FROM,
       EQNPOS_FROMTO,
       EQNPOS_OVER,
       EQNPOS_SQRT,
       EQNPOS__MAX
};

/*
* A "box" is a parsed mathematical expression as defined by the eqn.7
* grammar.
*/
struct  eqn_box {
       struct eqn_box   *parent;
       struct eqn_box   *prev;
       struct eqn_box   *next;
       struct eqn_box   *first;   /* First child node. */
       struct eqn_box   *last;    /* Last child node. */
       char             *text;    /* Text (or NULL). */
       char             *left;    /* Left-hand fence. */
       char             *right;   /* Right-hand fence. */
       char             *top;     /* Symbol above. */
       char             *bottom;  /* Symbol below. */
       size_t            expectargs; /* Maximal number of arguments. */
       size_t            args;    /* Actual number of arguments. */
       int               size;    /* Font size. */
#define EQN_DEFSIZE       INT_MIN
       enum eqn_boxt     type;    /* Type of node. */
       enum eqn_fontt    font;    /* Font in this box. */
       enum eqn_post     pos;     /* Position of the next box. */
};