1 files changed, 92 insertions, 0 deletions
diff --git a/utils/Spiff/exact.c b/utils/Spiff/exact.c
new file mode 100644
index 0000000..3bcce5c
--- /dev/null
+++ b/utils/Spiff/exact.c
@@ -0,0 +1,92 @@
+/*                        Copyright (c) 1988 Bellcore
+**                            All Rights Reserved
+**       Permission is granted to copy or use this program, EXCEPT that it
+**       may not be sold for profit, the copyright notice must be reproduced
+**       on copies, and credit should be given to Bellcore where it is due.
+**       BELLCORE MAKES NO WARRANTY AND ACCEPTS NO LIABILITY FOR THIS PROGRAM.
+*/
+
+
+#ifndef lint
+static char rcsid[]= "$Header$";
+#endif
+
+#include "misc.h"
+#include "edit.h"
+
+/*
+**	routine to compare each object with its ordinal twin
+*/
+E_edit
+Q_do_exact(size1,size2,max_d,comflags)
+int size1;
+int size2;
+int max_d;
+int comflags;
+{
+	int i = 0;
+	int diffcnt = 0;
+	int last = Z_MIN(size1,size2);
+	int next_edit = 0;
+	E_edit last_ptr = E_NULL;
+	int start,tmp;
+	E_edit *script;
+
+	script = Z_ALLOC(max_d+1,E_edit);
+
+	if (size1 != size2)
+	{
+		(void) sprintf(Z_err_buf,"unequal number of tokens, %d and %d respectively\n",size1,size2);
+		Z_complain(Z_err_buf);
+	}
+
+	do
+	{
+		/*
+		**	skip identical objects
+		*/
+		while (i<last && (!X_com(i,i,comflags)))
+		{
+			i++;
+		}
+		start = i;
+		/*
+		**	see how many difference we have in a row
+		*/
+		while (i<last && X_com(i,i,comflags))
+		{
+			if ((diffcnt += 2) >= max_d+1)
+				Z_exceed(max_d);
+			i++;
+		}
+		/*
+		**	build the list of deletions
+		*/
+		for(tmp=start;tmp<i;tmp++,next_edit++)
+		{
+			script[next_edit] = E_edit_alloc();
+			E_setnext(script[next_edit],last_ptr);
+			last_ptr = script[next_edit];
+
+			E_setop(script[next_edit],E_DELETE);
+			E_setl1(script[next_edit],tmp+1);
+			/* no need to set line2, it is never used */
+			E_setl2(script[next_edit],0);
+		}
+		/*
+		**	build the list of insertions
+		*/
+		for(tmp=start;tmp<i;tmp++,next_edit++)
+		{
+			script[next_edit] = E_edit_alloc();
+			E_setnext(script[next_edit],last_ptr);
+			last_ptr = script[next_edit];
+
+			E_setop(script[next_edit],E_INSERT);
+			E_setl1(script[next_edit],i);
+			E_setl2(script[next_edit],tmp+1);
+		}
+	} while (i<last);
+
+	return(last_ptr);
+}