add boolean cast function

tests/test_lib_bools.rs

@@ -321,4 +321,100 @@ mod bool_lib_tests {
             panic!()
         }
     }
+
+    #[test]
+    fn test_boolcast_str_t() {
+        let document = "(bool 'true')";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(b)
+        } else {
+            panic!()
+        }
+    }
+
+    #[test]
+    fn test_boolcast_str_f() {
+        let document = "(bool 'false')";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(!b)
+        } else {
+            panic!()
+        }
+    }
+
+    #[test]
+    fn test_boolcast_int_t() {
+        let document = "(bool 0)";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(b)
+        } else {
+            panic!()
+        }
+    }
+
+    #[test]
+    fn test_boolcast_int_f() {
+        let document = "(bool 12)";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(!b)
+        } else {
+            panic!()
+        }
+    }
+
+    #[test]
+    fn test_boolcast_float_t() {
+        let document = "(bool 0.0)";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(b)
+        } else {
+            panic!()
+        }
+    }
+
+    #[test]
+    fn test_boolcast_float_f() {
+        let document = "(bool 1.2)";
+        let test = lex(&document.to_string()).unwrap();
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms).unwrap();
+        dynamic_stdlib(&mut syms).unwrap();
+
+        if let Ctr::Bool(b) = *eval(&test, &mut syms).unwrap() {
+            assert!(!b)
+        } else {
+            panic!()
+        }
+    }
 }