Changeset d09e5a1 for filter.c

Timestamp:

May 31, 2003, 3:33:42 PM (20 years ago)

Author:

James M. Kretchmar <kretch@mit.edu>

Branches:

master, barnowl_perlaim, debian, owl, release-1.4, release-1.5, release-1.6, release-1.7, release-1.8, release-1.9

Children:

5e53c4a

Parents:

c86a35c

Message:

Added libfaim
Added basic AIM support, including the "aimlogin", "aimwrite" and
   "aimlogout" commands

File:

• filter.c (modified) (13 diffs)

filter.c

@@ -121 +121 @@
   char *field, *match;
 
-  /* create the working list */
+  /* create the working list of expression elements */
   fes=&(f->fes);
   owl_list_create(&work_fes);
@@ -129 +129 @@
   }
 
-  /* first go thru and turn all RE elements into true or false */
+  /* first go thru and evaluate all RE elements to true or false */
   match="";
   for (i=0; i<j; i++) {
@@ -152 +152 @@
       if (owl_message_is_type_zephyr(m)) {
         match="zephyr";
+      } else if (owl_message_is_type_aim(m)) {
+        match="aim";
       } else if (owl_message_is_type_admin(m)) {
         match="admin";
@@ -177 +179 @@
   }
 
-  
   /* call the recrsive helper */
   i=_owl_filter_message_match_recurse(f, m, &work_fes, 0, owl_list_get_size(&(f->fes))-1);
 
+  /* now there will be only one TRUE / FALSE, find it among the NULL's */
   tmp=0;
-  /* now we should have one value */
   for (i=0; i<j; i++) {
     fe=owl_list_get_element(&work_fes, i);
@@ -196 +197 @@
   }  
 
-  if (f->polarity) {
-    tmp=!tmp;
-  }
+  /* reverse the answer if negative polarity is in use */
+  if (f->polarity) tmp=!tmp;
+
   owl_list_free_simple(&work_fes);
   return(tmp);
@@ -207 +208 @@
   owl_filterelement *fe, *tmpfe=NULL;
 
-  /* deal with parens first */
+  /* Deal with parens first. */
   for (i=0; i<OWL_FILTER_MAX_DEPTH; i++) {
+    /* Find first open paren and matching close paren, store in x, y */
     score=x=y=0;
     for (i=start; i<=end; i++) {
@@ -231 +233 @@
     }
 
+    /* Simply the parens by removing them and evaluating what was in between */
     if (y>0) {
       /* null out the parens */
@@ -236 +239 @@
       owl_list_replace_element(fes, y, owl_global_get_filterelement_null(&g));
 
-      /* simplify the part that was in between */
+      /* evaluate expression in between */
       ret=_owl_filter_message_match_recurse(f, m, fes, x+1, y-1);
       if (ret<0) return(-1);
@@ -248 +251 @@
   }
   if (i==OWL_FILTER_MAX_DEPTH) {
+    /* hit the saftey limit, consider it invalid */
     return(-1);
   }
 
-  /* and / or / not */
+  /* Find AND / OR / NOT.
+   *   For binary expressions (AND/OR):
+   *     "type" is 1
+   *     "x" will index first val, "y" the operator and "z" the second val
+   *   For unary expressions (NOT):
+   *     "type" is 2
+   *     "x" will index the operator, "y" the value
+   *   "score" tallys how many expression elements have been found so far
+   */
   for (i=0; i<OWL_FILTER_MAX_DEPTH; i++) {
     type=score=x=y=z=0;
@@ -273 +285 @@
             y=i;
           } else {
+            /* it's not a valid binary expression */
             x=y=z=score=0;
           }
         } else if (type==2) {
           if (owl_filterelement_is_value(fe)) {
-            /* it's a valid "NOT expr" */
+            /* valid unary expression, we're done */
             y=i;
             break;
@@ -284 +297 @@
       } else if (score==2) {
         if (owl_filterelement_is_value(fe)) {
-          /* yes, it's a good match */
+          /* valid binary expression, we're done */
           z=i;
           break;
@@ -293 +306 @@
     }
 
-    /* process and / or */
+    /* simplify AND / OR */
     if ((type==1) && (z>0)) {
       fe=owl_list_get_element(fes, x);
@@ -326 +339 @@
       owl_list_replace_element(fes, y, tmpfe);
       owl_list_replace_element(fes, z, owl_global_get_filterelement_null(&g));
-    } else if ((type==2) && (y>0)) { /* process NOT */
+    } else if ((type==2) && (y>0)) {
+      /* simplify NOT */
       fe=owl_list_get_element(fes, y);
       owl_list_replace_element(fes, x, owl_global_get_filterelement_null(&g));