Add eval_number[_with_context] crate methods

Relates to #20

CHANGELOG.md

@@ -10,6 +10,7 @@
  * Add the `ValueType` enum that represents the type of a value for easier comparisons and matchings
  * Add `EvalexprResult<T>` type that uses the `EvalexprError` type (renamed from `Error`)
  * Add `Node::eval_number` and `Node::eval_number_with_context` to evaluate to int or float and silently converting to float
+ * Add `eval_number` and `eval_number_with_context` crate methods to evaluate to int or float and silently converting to float
 
 ### Removed
 

src/interface/mod.rs

@@ -104,6 +104,19 @@ pub fn eval_float(string: &str) -> Result<FloatType, EvalexprError> {
     }
 }
 
+/// Evaluate the given expression string into a float.
+/// If the result of the expression is an integer, it is silently converted into a float.
+///
+/// *See the [crate doc](index.html) for more examples and explanations of the expression format.*
+pub fn eval_number(string: &str) -> Result<FloatType, EvalexprError> {
+    match eval(string) {
+        Ok(Value::Float(float)) => Ok(float),
+        Ok(Value::Int(int)) => Ok(int as FloatType),
+        Ok(value) => Err(EvalexprError::expected_float(value)),
+        Err(error) => Err(error),
+    }
+}
+
 /// Evaluate the given expression string into a boolean.
 ///
 /// *See the [crate doc](index.html) for more examples and explanations of the expression format.*
@@ -162,6 +175,22 @@ pub fn eval_float_with_context(
     }
 }
 
+/// Evaluate the given expression string into a float with the given context.
+/// If the result of the expression is an integer, it is silently converted into a float.
+///
+/// *See the [crate doc](index.html) for more examples and explanations of the expression format.*
+pub fn eval_number_with_context(
+    string: &str,
+    context: &Context,
+) -> Result<FloatType, EvalexprError> {
+    match eval_with_context(string, context) {
+        Ok(Value::Float(float)) => Ok(float),
+        Ok(Value::Int(int)) => Ok(int as FloatType),
+        Ok(value) => Err(EvalexprError::expected_float(value)),
+        Err(error) => Err(error),
+    }
+}
+
 /// Evaluate the given expression string into a boolean with the given context.
 ///
 /// *See the [crate doc](index.html) for more examples and explanations of the expression format.*

tests/integration.rs

@@ -345,6 +345,8 @@ fn test_shortcut_functions() {
     assert_eq!(eval_float_with_context("3.3", &context), Ok(3.3));
     assert_eq!(eval_int("3"), Ok(3));
     assert_eq!(eval_int_with_context("3", &context), Ok(3));
+    assert_eq!(eval_number("3"), Ok(3.0));
+    assert_eq!(eval_number_with_context("3", &context), Ok(3.0));
     assert_eq!(eval_boolean("true"), Ok(true));
     assert_eq!(eval_boolean_with_context("true", &context), Ok(true));
     assert_eq!(eval_tuple("3,3"), Ok(vec![Value::Int(3), Value::Int(3)]));