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-rw-r--r--src/translators/btparse/tex_tree.c414
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diff --git a/src/translators/btparse/tex_tree.c b/src/translators/btparse/tex_tree.c
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+++ b/src/translators/btparse/tex_tree.c
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+/* ------------------------------------------------------------------------
+@NAME : tex_tree.c
+@DESCRIPTION: Functions for dealing with strings of TeX code: converting
+ them to tree representation, traversing the trees to glean
+ useful information, and converting back to string form.
+@GLOBALS :
+@CALLS :
+@CALLERS :
+@CREATED : 1997/05/29, Greg Ward
+@MODIFIED :
+@VERSION : $Id: tex_tree.c,v 1.4 1999/11/29 01:13:10 greg Rel $
+@COPYRIGHT : Copyright (c) 1996-99 by Gregory P. Ward. All rights reserved.
+
+ This file is part of the btparse library. This library is
+ free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2
+ of the License, or (at your option) any later version.
+-------------------------------------------------------------------------- */
+
+/*#include "bt_config.h"*/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "error.h"
+#include "btparse.h"
+/*#include "my_dmalloc.h"*/
+
+/* blech! temp hack until I make error.c perfect and magical */
+#define string_warning(w) fprintf (stderr, w);
+
+typedef struct treestack_s
+{
+ bt_tex_tree * node;
+ struct treestack_s
+ * prev,
+ * next;
+} treestack;
+
+
+/* ----------------------------------------------------------------------
+ * Stack manipulation functions
+ */
+
+/* ------------------------------------------------------------------------
+@NAME : push_treestack()
+@INPUT : *stack
+ node
+@OUTPUT : *stack
+@RETURNS :
+@DESCRIPTION: Creates and initializes new node in a stack, and pushes it
+ onto the stack.
+@GLOBALS :
+@CALLS :
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+static void
+push_treestack (treestack **stack, bt_tex_tree *node)
+{
+ treestack *newtop;
+
+ newtop = (treestack *) malloc (sizeof (treestack));
+ newtop->node = node;
+ newtop->next = NULL;
+ newtop->prev = *stack;
+
+ if (*stack != NULL) /* stack already has some entries */
+ {
+ (*stack)->next = newtop;
+ *stack = newtop;
+ }
+
+ *stack = newtop;
+
+} /* push_treestack() */
+
+
+/* ------------------------------------------------------------------------
+@NAME : pop_treestack
+@INPUT : *stack
+@OUTPUT : *stack
+@RETURNS :
+@DESCRIPTION: Pops an entry off of a stack of tex_tree nodes, frees up
+ the wrapper treestack node, and returns the popped tree node.
+@GLOBALS :
+@CALLS :
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+static bt_tex_tree *
+pop_treestack (treestack **stack)
+{
+ treestack * oldtop;
+ bt_tex_tree * node;
+
+ if (*stack == NULL)
+ internal_error ("attempt to pop off empty stack");
+ oldtop = (*stack)->prev;
+ node = (*stack)->node;
+ free (*stack);
+ if (oldtop != NULL)
+ oldtop->next = NULL;
+ *stack = oldtop;
+ return node;
+
+} /* pop_treestack() */
+
+
+/* ----------------------------------------------------------------------
+ * Tree creation/destruction functions
+ */
+
+/* ------------------------------------------------------------------------
+@NAME : new_tex_tree
+@INPUT : start
+@OUTPUT :
+@RETURNS : pointer to newly-allocated node
+@DESCRIPTION: Allocates and initializes a bt_tex_tree node.
+@GLOBALS :
+@CALLS :
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+static bt_tex_tree *
+new_tex_tree (char *start)
+{
+ bt_tex_tree * node;
+
+ node = (bt_tex_tree *) malloc (sizeof (bt_tex_tree));
+ node->start = start;
+ node->len = 0;
+ node->child = node->next = NULL;
+ return node;
+}
+
+
+/* ------------------------------------------------------------------------
+@NAME : bt_build_tex_tree
+@INPUT : string
+@OUTPUT :
+@RETURNS : pointer to a complete tree; call bt_free_tex_tree() to free
+ the entire tree
+@DESCRIPTION: Traverses a string looking for TeX groups ({...}), and builds
+ a tree containing pointers into the string and describing
+ its brace-structure.
+@GLOBALS :
+@CALLS :
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+bt_tex_tree *
+bt_build_tex_tree (char * string)
+{
+ int i;
+ int depth;
+ int len;
+ bt_tex_tree
+ * top,
+ * cur,
+ * new;
+ treestack
+ * stack;
+
+ i = 0;
+ depth = 0;
+ len = strlen (string);
+ top = new_tex_tree (string);
+ stack = NULL;
+
+ cur = top;
+
+ while (i < len)
+ {
+ switch (string[i])
+ {
+ case '{': /* go one level deeper */
+ {
+ if (i == len-1) /* open brace in last character? */
+ {
+ string_warning ("unbalanced braces: { at end of string");
+ goto error;
+ }
+
+ new = new_tex_tree (string+i+1);
+ cur->child = new;
+ push_treestack (&stack, cur);
+ cur = new;
+ depth++;
+ break;
+ }
+ case '}': /* pop level(s) off */
+ {
+ while (i < len && string[i] == '}')
+ {
+ if (stack == NULL)
+ {
+ string_warning ("unbalanced braces: extra }");
+ goto error;
+ }
+ cur = pop_treestack (&stack);
+ depth--;
+ i++;
+ }
+ i--;
+
+ if (i == len-1) /* reached end of string? */
+ {
+ if (depth > 0) /* but not at depth 0 */
+ {
+ string_warning ("unbalanced braces: not enough }'s");
+ goto error;
+ }
+
+ /*
+ * if we get here, do nothing -- we've reached the end of
+ * the string and are at depth 0, so will just fall out
+ * of the while loop at the end of this iteration
+ */
+ }
+ else /* still have characters left */
+ { /* to worry about */
+ new = new_tex_tree (string+i+1);
+ cur->next = new;
+ cur = new;
+ }
+
+ break;
+ }
+ default:
+ {
+ cur->len++;
+ }
+
+ } /* switch */
+
+ i++;
+
+ } /* while i */
+
+ if (depth > 0)
+ {
+ string_warning ("unbalanced braces (not enough }'s)");
+ goto error;
+ }
+
+ return top;
+
+error:
+ bt_free_tex_tree (&top);
+ return NULL;
+
+} /* bt_build_tex_tree() */
+
+
+/* ------------------------------------------------------------------------
+@NAME : bt_free_tex_tree
+@INPUT : *top
+@OUTPUT : *top (set to NULL after it's free()'d)
+@RETURNS :
+@DESCRIPTION: Frees up an entire tree created by bt_build_tex_tree().
+@GLOBALS :
+@CALLS : itself, free()
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+void
+bt_free_tex_tree (bt_tex_tree **top)
+{
+ if ((*top)->child) bt_free_tex_tree (&(*top)->child);
+ if ((*top)->next) bt_free_tex_tree (&(*top)->next);
+ free (*top);
+ *top = NULL;
+}
+
+
+
+/* ----------------------------------------------------------------------
+ * Tree traversal functions
+ */
+
+/* ------------------------------------------------------------------------
+@NAME : bt_dump_tex_tree
+@INPUT : node
+ depth
+ stream
+@OUTPUT :
+@RETURNS :
+@DESCRIPTION: Dumps a TeX tree: one node per line, depth indented according
+ to depth.
+@GLOBALS :
+@CALLS : itself
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+void
+bt_dump_tex_tree (bt_tex_tree *node, int depth, FILE *stream)
+{
+ char buf[256];
+
+ if (node == NULL)
+ return;
+
+ if (node->len > 255)
+ internal_error ("augughgh! buf too small");
+ strncpy (buf, node->start, node->len);
+ buf[node->len] = (char) 0;
+
+ fprintf (stream, "%*s[%s]\n", depth*2, "", buf);
+
+ bt_dump_tex_tree (node->child, depth+1, stream);
+ bt_dump_tex_tree (node->next, depth, stream);
+
+}
+
+
+/* ------------------------------------------------------------------------
+@NAME : count_length
+@INPUT : node
+@OUTPUT :
+@RETURNS :
+@DESCRIPTION: Counts the total number of characters that will be needed
+ to print a string reconstructed from a TeX tree. (Length
+ of string in each node, plus two [{ and }] for each down
+ edge.)
+@GLOBALS :
+@CALLS : itself
+@CALLERS : bt_flatten_tex_tree
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+static int
+count_length (bt_tex_tree *node)
+{
+ if (node == NULL) return 0;
+ return
+ node->len +
+ (node->child ? 2 : 0) +
+ count_length (node->child) +
+ count_length (node->next);
+}
+
+
+/* ------------------------------------------------------------------------
+@NAME : flatten_tree
+@INPUT : node
+ *offset
+@OUTPUT : *buf
+ *offset
+@RETURNS :
+@DESCRIPTION: Dumps a reconstructed string ("flat" representation of the
+ tree) into a pre-allocated buffer, starting at a specified
+ offset.
+@GLOBALS :
+@CALLS : itself
+@CALLERS : bt_flatten_tex_tree
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+static void
+flatten_tree (bt_tex_tree *node, char *buf, int *offset)
+{
+ strncpy (buf + *offset, node->start, node->len);
+ *offset += node->len;
+
+ if (node->child)
+ {
+ buf[(*offset)++] = '{';
+ flatten_tree (node->child, buf, offset);
+ buf[(*offset)++] = '}';
+ }
+
+ if (node->next)
+ {
+ flatten_tree (node->next, buf, offset);
+ }
+}
+
+
+/* ------------------------------------------------------------------------
+@NAME : bt_flatten_tex_tree
+@INPUT : top
+@OUTPUT :
+@RETURNS : flattened string representation of the tree (as a string
+ allocated with malloc(), so you should free() it when
+ you're done with it)
+@DESCRIPTION: Counts the number of characters needed for a "flat"
+ string representation of a tree, allocates a string of
+ that size, and generates the string.
+@GLOBALS :
+@CALLS : count_length, flatten_tree
+@CALLERS :
+@CREATED : 1997/05/29, GPW
+@MODIFIED :
+-------------------------------------------------------------------------- */
+char *
+bt_flatten_tex_tree (bt_tex_tree *top)
+{
+ int len;
+ int offset;
+ char * buf;
+
+ len = count_length (top);
+ buf = (char *) malloc (sizeof (char) * (len+1));
+ offset = 0;
+ flatten_tree (top, buf, &offset);
+ return buf;
+}
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