[lcd4linux @ 2003-10-06 04:34:06 by reinelt]

expression evaluator added

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@256 3ae390bd-cb1e-0410-b409-cd5a39f66f1f

1 files changed, 90 insertions, 0 deletions

diff --git a/evaluator.h b/evaluator.h
new file mode 100644
index 0000000..661b967
--- /dev/null
+++ b/evaluator.h
@@ -0,0 +1,90 @@
+/* $Id: evaluator.h,v 1.1 2003/10/06 04:34:06 reinelt Exp $
+ *
+ * expression evaluation
+ *
+ * based on EE (Expression Evaluator) which is 
+ * (c) 1992 Mark Morley <morley@Camosun.BC.CA>
+ * 
+ * heavily modified 2003 by Michael Reinelt <reinelt@eunet.at>
+ *
+ * FIXME: GPL or not GPL????
+ *
+ * $Log: evaluator.h,v $
+ * Revision 1.1  2003/10/06 04:34:06  reinelt
+ * expression evaluator added
+ *
+ */
+
+
+/***************************************************************************
+ **                                                                       **
+ ** EE.C         Expression Evaluator                                     **
+ **                                                                       **
+ ** AUTHOR:      Mark Morley                                              **
+ ** COPYRIGHT:   (c) 1992 by Mark Morley                                  **
+ ** DATE:        December 1991                                            **
+ ** HISTORY:     Jan 1992 - Made it squash all command line arguments     **
+ **                         into one big long string.                     **
+ **                       - It now can set/get VMS symbols as if they     **
+ **                         were variables.                               **
+ **                       - Changed max variable name length from 5 to 15 **
+ **              Jun 1992 - Updated comments and docs                     **
+ **                                                                       **
+ ** You are free to incorporate this code into your own works, even if it **
+ ** is a commercial application.  However, you may not charge anyone else **
+ ** for the use of this code!  If you intend to distribute your code,     **
+ ** I'd appreciate it if you left this message intact.  I'd like to       **
+ ** receive credit wherever it is appropriate.  Thanks!                   **
+ **                                                                       **
+ ** I don't promise that this code does what you think it does...         **
+ **                                                                       **
+ ** Please mail any bug reports/fixes/enhancments to me at:               **
+ **      morley@camosun.bc.ca                                             **
+ ** or                                                                    **
+ **      Mark Morley                                                      **
+ **      3889 Mildred Street                                              **
+ **      Victoria, BC  Canada                                             **
+ **      V8Z 7G1                                                          **
+ **      (604) 479-7861                                                   **
+ **                                                                       **
+ ***************************************************************************/
+
+
+#ifndef _EVALUATOR_H_
+#define _EVALUATOR_H_
+
+
+// RESULT bitmask
+#define R_NUMBER 1
+#define R_STRING 2
+
+typedef struct {
+  int type;
+  double number;
+  char  *string;
+} RESULT;
+
+
+// error codes
+#define E_OK      0 /* Successful evaluation */
+#define E_SYNTAX  1 /* Syntax error */
+#define E_UNBALAN 2 /* Unbalanced parenthesis */
+#define E_DIVZERO 3 /* Attempted division by zero */
+#define E_UNKNOWN 4 /* Reference to unknown variable */
+#define E_BADFUNC 5 /* Unrecognised function */
+#define E_NUMARGS 6 /* Wrong number of arguments to function */
+#define E_NOARG   7 /* Missing an argument to a function */
+#define E_EMPTY   8 /* Empty expression */
+
+
+int AddConstant (char *name, double value);
+int AddFunction (char *name, int args, void (*func)());
+
+RESULT* SetResult (RESULT **result, int type, void *value);
+
+double R2N (RESULT *result);
+char*  R2S (RESULT *result);
+
+int Eval (char* expression, RESULT *result);
+
+#endif