/*      $Id: eqn.h,v 1.1 2018/12/13 05:23:38 schwarze Exp $ */
/*
 * Copyright (c) 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
 *
 * 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. */
};