Use tanh-sinh algorithm to integrate and improve differenate precision (#158)

* feat: preliminary Tanh-Sinh implementation

* feat: another way to implement tanh-sinh

* feat: get rid of the pre_calculated stuff (failed to run)

* feat: tanh-sinh complete, boole's back for first calculation

* feat: higher percision derivatives function

* fix: qthsh char error

* chore: remove a stuff

* chore: testing function and pure qthsh

* chore: remove boole_rule

* chore: bring integrate_function back

kalk/src/kalk_value/mod.rs

@@ -571,6 +571,21 @@ impl KalkValue {
         }
     }
 
+    pub fn is_finite(&self) -> bool {
+        //#[cfg(feature = "rug")]
+        if let KalkValue::Number(real, imaginary, _) = self {
+            real.is_finite() && imaginary.is_finite()
+        } else {
+            false
+        }
+        //#[cfg(not(feature = "rug"))]
+        //if let KalkValue::Number(real, imaginary, _) = self {
+        //    real.is_finite() && imaginary.is_finite()
+        //} else {
+        //    false
+        //}
+    }
+
     pub fn to_scientific_notation(
         &self,
         complex_number_type: ComplexNumberType,