add modulo (%) operator

wimh · Apr 18, 2016 · e2d629f · e2d629f
1 parent 824c138
commit e2d629f
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Showing 7 changed files with 28 additions and 5 deletions.
diff --git a/panel-plugin/eval.c b/panel-plugin/eval.c
@@ -103,6 +103,9 @@ static double eval(node_t *parsetree)
         case OP_DIV:
             r = left / right;
             break;
+        case OP_MODULO:
+            r = fmod(left, right);
+            break;
         case OP_POW:
             r = pow(left, right);
             break;
@@ -118,7 +121,7 @@ static double eval(node_t *parsetree)
         arg = eval(parsetree->right);
         r = parsetree->val.fun(arg);
         break;
-        
+
     default:
         g_assert_not_reached();
     }

diff --git a/panel-plugin/grammar.txt b/panel-plugin/grammar.txt
@@ -19,7 +19,7 @@ pow             ->      ( expr )  |  function ( expr )  |  constant |  NUM
 
 add_op          ->      +  |  -
 
-mult_op         ->      *  |  /
+mult_op         ->      *  |  /  |  %
 
 pow_op          ->      ^  |  **
 

diff --git a/panel-plugin/lexer.c b/panel-plugin/lexer.c
@@ -24,7 +24,7 @@
 
 static gboolean isoperator(int c)
 {
-    if (c == '+' || c == '-' || c == '*' || c == '/' || c == '^')
+    if (c == '+' || c == '-' || c == '*' || c == '/' || c == '%' || c == '^')
         return TRUE;
     else
         return FALSE;

diff --git a/panel-plugin/parser.c b/panel-plugin/parser.c
@@ -121,7 +121,7 @@ static gboolean is_mult_op(char op)
     /*
     return op[0] == '/' || (op[0] == '*' && op[1] == '\0')
     */
-    return op == '/' || op == '*';
+    return op == '/' || op == '*' || op == '%';
 }
 
 /*
@@ -388,8 +388,11 @@ static node_t *get_factortail(token_stack_t *stack, node_t *left_expr, GError **
     case '/':
         op->val.op = OP_DIV;
         break;
+    case '%':
+        op->val.op = OP_MODULO;
+        break;
     default:
-        set_error(err, "Expected '*' or '/'", token);
+        set_error(err, "Expected '*', '/' or '%'", token);
         g_free(op);
         return left_expr;
     }

diff --git a/panel-plugin/parsetree.h b/panel-plugin/parsetree.h
@@ -26,6 +26,7 @@ typedef enum { NODE_OPERATOR, NODE_NUMBER, NODE_FUNCTION } node_type_t;
 typedef enum { OP_PLUS, OP_MINUS,
                OP_UMINUS,
                OP_TIMES, OP_DIV,
+               OP_MODULO,
                OP_POW } operator_type_t;
 
 typedef struct _node_t {

diff --git a/tests/Makefile.am b/tests/Makefile.am
@@ -6,6 +6,7 @@ EXTRA_DIST =								\
 TESTS = 								\
 	test-simple-expr.awk						\
 	test-minus.awk							\
+	test-modulo.awk							\
 	test-e-notation.awk						\
 	test-abs.awk							\
 	test-sqrt.awk							\

diff --git a/tests/test-modulo.awk b/tests/test-modulo.awk
@@ -0,0 +1,15 @@
+#!/usr/bin/awk -f
+
+function abs(x) {
+    return (x < 0) ? -x : x
+}
+
+BEGIN{
+    expr = "'1 + 27 % 5 * 3 + -3 % 2'"
+    "../panel-plugin/calctest " expr | getline res
+    if (abs(res - 6) > 1.0e-14) {
+        print res
+        exit 1
+    } else
+        exit 0
+}