add comparison operators

[calc.git] / parser.c

diff --git a/parser.c b/parser.c
index 43595e53845ade3e2476755fb8d791a620416ecf..844e9417f18b19d2ec4b32780e514dda6338c224 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -69,7 +69,7 @@ void delelement (element_t *root)
 
 /* functions */
 
-#define NB_OPERATORS 6
+#define NB_OPERATORS 12
 
 keyword_t operators[NB_OPERATORS] = {
     { "+\t", Add, 2, 1, 1},
@@ -77,7 +77,13 @@ keyword_t operators[NB_OPERATORS] = {
     { "*",   Mul, 2, 1, 2},
     { "/",   Div, 2, 1, 2},
     { "%",   Mod, 2, 1, 3},
-    { "^",   Pow, 2, 1, 4}
+    { "^",   Pow, 2, 1, 4},
+    { "==",  Equal, 2, 2, 6},
+    { "!=",  Diff, 2, 2, 6},
+    { ">=",  Ge, 2, 2, 6},
+    { "<=",  Le, 2, 2, 6},
+    { ">",   Gt, 2, 1, 6},
+    { "<",   Lt, 2, 1, 6}
 };
 
 #define NB_FUNCTIONS 12
@@ -91,7 +97,7 @@ keyword_t functions[NB_FUNCTIONS] = {
     { "log",  Log, 1, 3, 5},
     { "sto",  Store, 2, 3, 5},
     { "rcl",  Recall, 1, 3, 5},
-    { "disp",  Disp, 0, 4, 5},
+    { "disp", Disp, 0, 4, 5},
     { "quit", Quit, 0, 4, 5},
     { "help", Help, 0, 4, 5}
 };
@@ -382,6 +388,12 @@ void print_element (element_t *root, int level)
     case Ans: func = "Ans"; break;
     case Pi: func = "Pi"; break;
     case E: func = "E"; break;
+    case Equal: func = "Equal"; break;
+    case Diff: func = "Different"; break;
+    case Ge: func = "Greater or equal"; break;
+    case Le: func = "Lesser or equal"; break;
+    case Gt: func = "Greater"; break;
+    case Lt: func = "Lesser"; break;
     }
 
     fprintf (stdout, "Function: %s\n", func);
@@ -445,6 +457,8 @@ void help (void)
     fprintf (stdout, "calc is a simple calculator\n\n");
     fprintf (stdout, "supported operators:\n");
     fprintf (stdout, " + - * / %% ^\n\n");
+    fprintf (stdout, "camparison operators:\n");
+    fprintf (stdout, " == != >= <= > <\n\n");
     fprintf (stdout, "supported functions:\n");
     fprintf (stdout, " pow sqrt cos sin atan log exp\n\n");
     fprintf (stdout, "storage functions:\n");
@@ -502,6 +516,12 @@ double evaluate_element (element_t *root, char mask)
     case Mod:
     case Pow:
     case Store:
+    case Equal:
+    case Diff:
+    case Ge:
+    case Le:
+    case Gt:
+    case Lt:
         if (root->ops[1]) {
             op1 = evaluate_element (root->ops[1], nextmask);
         } else if (root->func != Store) {
@@ -555,6 +575,12 @@ double evaluate_element (element_t *root, char mask)
     case Ans: return answer;
     case Pi: return M_PI;
     case E: return M_E;
+    case Equal: return op0 == op1;
+    case Diff: return op0 != op1;
+    case Ge: return op0 >= op1;
+    case Le: return op0 <= op1;
+    case Gt: return op0 > op1;
+    case Lt: return op0 < op1;
     }
 
     return 0;