doc: Add more information to the README

README.md

@@ -5,7 +5,9 @@
 [![Build Status](https://travis-ci.org/Kerollmops/ripin-rs.svg)](https://travis-ci.org/Kerollmops/ripin-rs)
 [![Coverage Status](https://coveralls.io/repos/github/Kerollmops/ripin-rs/badge.svg?branch=master)](https://coveralls.io/github/Kerollmops/ripin-rs?branch=master)
 
-A library to handle Reverse Polish notated expressions
+A library to handle [`Reverse Polish notated`](https://en.wikipedia.org/wiki/Reverse_Polish_notation) expressions.
+
+Ripin can also evaluate variable expressions and is not limited to string tokens, it can handle any iterator type, the only limit is your imagination. There is [`examples`](https://github.com/Kerollmops/ripin-rs/tree/master/examples) to understand how to implement your own expression from custom types.
 
 ## Installation
 
@@ -37,19 +39,6 @@ let expr = FloatExpr::<f32>::from_iter(tokens).unwrap();
 println!("Expression {:?} gives {:?}", expr_str, expr.evaluate())
 ```
 
-You don't care about floating-point expressions ? Why not integer expression evaluation ?
-
-```rust
-use ripin::expression::IntExpr;
-
-let expr_str = "3 4 + 2 *"; // (3 + 4) * 2
-let tokens = expr_str.split_whitespace();
-
-let expr = IntExpr::<i32>::from_iter(tokens).unwrap();
-
-println!("Expression {:?} gives {:?}", expr_str, expr.evaluate())
-```
-
 It is also possible to use variables in your expressions to make them more "variable".
 
 ```rust
@@ -58,7 +47,7 @@ use ripin::variable::VarIdx;
 
 let variables = vec![3.0, 500.0]; // Try changing variables here
 
-let expr_str = "3 4 + 2 * $0 -"; // (3 + 4) * 2 - $0
+let expr_str = "3 $1 + 2 * $0 -"; // (3 + $1) * 2 - $0
 let tokens = expr_str.split_whitespace();
 
 let expr = VariableFloatExpr::<f32, VarIdx>::from_iter(tokens).unwrap();

src/expression.rs

@@ -33,13 +33,17 @@ pub struct Expression<T, V, E: Evaluate<T>> {
 }
 
 impl<T: Copy, V: Copy, E: Evaluate<T> + Copy> Expression<T, V, E> {
-    /// Evaluate the `RPN` expression. Returns the result
+    /// Evaluate `RPN` expressions. Returns the result
     /// or the [`evaluate Error`](../evaluate/trait.Evaluate.html#associatedtype.Err).
     pub fn evaluate(&self) -> Result<T, E::Err> where (): From<V> {
         self.evaluate_with_variables(DummyVariables::default())
     }
 
-    // TODO doc
+    /// Evaluate `RPN` expressions containing variables. Returns the result
+    /// or the [`evaluate Error`](../evaluate/trait.Evaluate.html#associatedtype.Err).
+    ///
+    /// # Panics
+    /// Panics if a variables doesn't exists in the variable container.
     pub fn evaluate_with_variables<I, C>(&self, variables: C) -> Result<T, E::Err>
         where V: Into<I>,
               C: Index<I, Output=T>