From dda8ef14aca2b99d620323b3173e967456c92314 Mon Sep 17 00:00:00 2001
From: jaortega <jaortega>
Date: Sat, 2 Dec 2000 22:32:48 +0000
Subject: added mix_eval_t, a w-expression evaluator

---
 mixlib/mix_eval.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 mixlib/mix_eval.c

(limited to 'mixlib/mix_eval.c')

diff --git a/mixlib/mix_eval.c b/mixlib/mix_eval.c
new file mode 100644
index 0000000..683b8ac
--- /dev/null
+++ b/mixlib/mix_eval.c
@@ -0,0 +1,154 @@
+/* -*-c-*- -------------- mix_eval.c :
+ * Implementation of the functions declared in mix_eval.h
+ * ------------------------------------------------------------------
+ *  Last change: Time-stamp: "00/12/02 23:13:47 jose"
+ * ------------------------------------------------------------------
+ * Copyright (C) 2000 jose antonio ortega ruiz <jaortega@acm.org>
+ *  
+ * This program 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.
+ *  
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *  
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *  
+ */
+
+
+#include "xmix_eval.h"
+
+
+static const gchar *errors_[] = {
+  N_("Successful evaluation"),
+  N_("Syntax error in expression"),
+  N_("Out of range F-specification"),
+  N_("Mismatched parenthesis"),
+  N_("Undefined symbol"),
+  N_("Internal error")
+};
+
+
+/* create a new evaluator */
+mix_eval_t *
+mix_eval_new (void) 
+{
+  mix_eval_t *result = g_new (mix_eval_t, 1);
+  result->table = mix_symbol_table_new ();
+  if (result->table == NULL) {
+    g_free (result);
+    return NULL;
+  }
+  result->towner = TRUE;
+  result->value = MIX_WORD_ZERO;
+  result->errpos = 0;
+  return result;
+}
+
+/* create a new evaluator with an external symbol table */
+mix_eval_t *
+mix_eval_new_with_table (mix_symbol_table_t *table)
+{
+  mix_eval_t *result = g_new (mix_eval_t, 1);
+  result->table = table;
+  result->towner = FALSE;
+  result->value = MIX_WORD_ZERO;
+  result->errpos = 0;
+  return result;
+}
+
+/* delete */
+void
+mix_eval_delete (mix_eval_t *eval)
+{
+  g_return_if_fail (eval);
+  if (eval->table && eval->towner) {
+    mix_symbol_table_delete (eval->table);
+  }
+  g_free (eval);
+}
+
+/* eval an expression */
+mix_eval_result_t
+mix_eval_expression_with_loc (mix_eval_t *eval, const gchar *expr,
+			      mix_short_t loc)
+{
+  mix_eval_data_ data;
+  
+  if (expr == NULL || eval == NULL)
+    return MIX_EVAL_INTERN;
+  data.expr = g_strdup_printf ("%s\n", expr);
+  data.table = eval->table;
+  data.errpos = eval->errpos;
+  data.value = eval->value;
+  data.loc = loc;
+  eval->result = mix_eval_expr (&data);
+  if (eval->result == MIX_EVAL_OK) {
+    eval->value = data.value;
+    eval->errpos = -1;
+  } else {
+    eval->errpos = data.errpos;
+  }
+  g_free (data.expr);
+    
+  return eval->result;
+}
+
+/* get the result of the last evaluation */
+mix_word_t
+mix_eval_value (mix_eval_t *eval) 
+{
+  g_return_val_if_fail (eval != NULL, MIX_WORD_ZERO);
+  return eval->value;
+}
+
+/* get the last eval result code */
+mix_eval_result_t 
+mix_eval_last_error (mix_eval_t *eval) 
+{
+  g_return_val_if_fail (eval != NULL, MIX_EVAL_INTERN);
+  return eval->result;
+}
+
+/* get the last error string */
+const gchar*
+mix_eval_last_error_string (mix_eval_t *eval) 
+{
+  g_return_val_if_fail (eval != NULL, errors_[MIX_EVAL_INTERN]);
+  return errors_[eval->result];
+}
+
+/* get the position of last error */
+guint
+mix_eval_last_error_pos (mix_eval_t *eval)
+{
+  g_return_val_if_fail (eval != NULL, 0);
+  return eval->errpos;
+}
+
+/* add, or redefine, a symbol. see mix_symbol_table.h for
+   possible outcomes. */
+gint
+mix_eval_set_symbol (mix_eval_t *eval, const gchar *symbol,
+		     mix_word_t value)
+{
+  g_return_val_if_fail (eval != NULL && eval->table != NULL,
+			MIX_SYM_FAIL);
+  return mix_symbol_table_insert (eval->table, symbol, value);
+}
+
+void
+mix_eval_remove_symbol (mix_eval_t *eval, const gchar *symbol)
+{
+  g_return_if_fail (eval != NULL && eval->table != NULL);
+  mix_symbol_table_remove (eval->table, symbol);
+}
+
+  
+  
-- 
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