<commit_before>use std::fmt;
use std::ops::Index;
use stack::Stack;
use evaluate::Evaluate;
use variable::DummyVariables;
use convert_ref::{TryFromRef, TryIntoRef};

/// Used to specify an `Operand` or an `Evaluator`.
#[derive(Debug, Copy, Clone)]
pub enum Arithm<T, V, E: Evaluate<T>> {
    Operand(T),
    Variable(V),
    Evaluator(E),
}

/// Interpret a [`Reverse Polish notated`] expression (cf. `3 4 +`).
///
/// `Evaluate` method returns the valid result or an [`Evaluate::Err`]
/// if the evaluation fails.
///
/// `Expressions` are constructed from [`str`] the most of the time.
/// Use the [`try_into_ref()`] method to create an `Expression` type,
/// the result contain informations about the possible error at conversion time.
///
/// [`Reverse Polish notated`]: https://en.wikipedia.org/wiki/Reverse_Polish_notation
/// [`Evaluate::Err`]: ../evaluate/trait.Evaluate.html#associatedtype.Err
/// [`str`]: https://doc.rust-lang.org/std/str/index.html
/// [`try_into_ref()`]: ../convert_ref/trait.TryIntoRef.html
#[derive(Debug)]
pub struct Expression<T, V, E: Evaluate<T>> {
    stack_max: usize, // TODO rename max_stack
    expr: Vec<Arithm<T, V, E>>,
}

impl<T: Copy, V: Copy, E: Evaluate<T> + Copy> Expression<T, V, E> {
    /// Evaluate the `RPN` expression. 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())
    }

    pub fn evaluate_with_variables<I, C>(&self, variables: C) -> Result<T, E::Err>
        where V: Into<I>,
              C: Index<I, Output=T>
    {
        let mut stack = Stack::with_capacity(self.stack_max);
        for arithm in &self.expr {
            match *arithm {
                Arithm::Operand(operand) => stack.push(operand),
                Arithm::Variable(var) => stack.push(*variables.index(var.into())),
                Arithm::Evaluator(evaluator) => evaluator.evaluate(&mut stack)?,
            }
        }
        Ok(stack.pop().unwrap())
    }
}

impl<T, V, E: Evaluate<T>> Expression<T, V, E> {
    pub fn from_iter<A, I>(iter: I) -> Result<Expression<T, V, E>,
                                              ExprResult<<E as TryFromRef<A>>::Err,
                                                         <V as TryFromRef<A>>::Err,
                                                         <T as TryFromRef<A>>::Err>>
        where T: TryFromRef<A>,
              V: TryFromRef<A>,
              E: TryFromRef<A>,
              I: IntoIterator<Item=A>
    {
        let final_expr: Result<Vec<_>, _> = iter.into_iter().map(|token| {
            match TryIntoRef::<E>::try_into_ref(&token) {
                Ok(eval) => Ok(Arithm::Evaluator(eval)),
                Err(eval_err) => {
                    match TryIntoRef::<V>::try_into_ref(&token) {
                        Ok(var) => Ok(Arithm::Variable(var)),
                        Err(var_err) => {
                            match TryIntoRef::<T>::try_into_ref(&token) {
                                Ok(op) => Ok(Arithm::Operand(op)),
                                Err(op_err) => Err(ExprResult::InvalidToken {
                                    evaluator: eval_err,
                                    variable: var_err,
                                    operand: op_err,
                                })
                            }
                        }
                    }
                }
            }
        }).collect();
        final_expr.and_then(|final_expr| {
            match Expression::check_validity(&final_expr) {
                Ok(_) => Ok(Expression {
                    stack_max: Expression::compute_stack_max(&final_expr),
                    expr: final_expr
                }),
                Err(err) => Err(ExprResult::OperandErr(err)),
            }
        })
    }
}

/// Used to specify the error during the conversion.
#[derive(Debug, PartialEq)]
pub enum ExprResult<A, B, C> {
    OperandErr(OperandErr),
    InvalidToken {
        evaluator: A,
        variable: B,
        operand: C
    },
}

/// Used to specify an error related to wrong number of operands in expression.
#[derive(Debug, PartialEq)]
pub enum OperandErr {
    TooManyOperands,
    NotEnoughOperand,
}

impl<T, V, E: Evaluate<T>> Expression<T, V, E> {<commit_msg>expression: Rename stack_max to max_stack for more clarity<commit_after>use std::fmt;
use std::ops::Index;
use stack::Stack;
use evaluate::Evaluate;
use variable::DummyVariables;
use convert_ref::{TryFromRef, TryIntoRef};

/// Used to specify an `Operand` or an `Evaluator`.
#[derive(Debug, Copy, Clone)]
pub enum Arithm<T, V, E: Evaluate<T>> {
    Operand(T),
    Variable(V),
    Evaluator(E),
}

/// Interpret a [`Reverse Polish notated`] expression (cf. `3 4 +`).
///
/// `Evaluate` method returns the valid result or an [`Evaluate::Err`]
/// if the evaluation fails.
///
/// `Expressions` are constructed from [`str`] the most of the time.
/// Use the [`try_into_ref()`] method to create an `Expression` type,
/// the result contain informations about the possible error at conversion time.
///
/// [`Reverse Polish notated`]: https://en.wikipedia.org/wiki/Reverse_Polish_notation
/// [`Evaluate::Err`]: ../evaluate/trait.Evaluate.html#associatedtype.Err
/// [`str`]: https://doc.rust-lang.org/std/str/index.html
/// [`try_into_ref()`]: ../convert_ref/trait.TryIntoRef.html
#[derive(Debug)]
pub struct Expression<T, V, E: Evaluate<T>> {
    max_stack: usize,
    expr: Vec<Arithm<T, V, E>>,
}

impl<T: Copy, V: Copy, E: Evaluate<T> + Copy> Expression<T, V, E> {
    /// Evaluate the `RPN` expression. 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())
    }

    pub fn evaluate_with_variables<I, C>(&self, variables: C) -> Result<T, E::Err>
        where V: Into<I>,
              C: Index<I, Output=T>
    {
        let mut stack = Stack::with_capacity(self.max_stack);
        for arithm in &self.expr {
            match *arithm {
                Arithm::Operand(operand) => stack.push(operand),
                Arithm::Variable(var) => stack.push(*variables.index(var.into())),
                Arithm::Evaluator(evaluator) => evaluator.evaluate(&mut stack)?,
            }
        }
        Ok(stack.pop().unwrap())
    }
}

impl<T, V, E: Evaluate<T>> Expression<T, V, E> {
    pub fn from_iter<A, I>(iter: I) -> Result<Expression<T, V, E>,
                                              ExprResult<<E as TryFromRef<A>>::Err,
                                                         <V as TryFromRef<A>>::Err,
                                                         <T as TryFromRef<A>>::Err>>
        where T: TryFromRef<A>,
              V: TryFromRef<A>,
              E: TryFromRef<A>,
              I: IntoIterator<Item=A>
    {
        let final_expr: Result<Vec<_>, _> = iter.into_iter().map(|token| {
            match TryIntoRef::<E>::try_into_ref(&token) {
                Ok(eval) => Ok(Arithm::Evaluator(eval)),
                Err(eval_err) => {
                    match TryIntoRef::<V>::try_into_ref(&token) {
                        Ok(var) => Ok(Arithm::Variable(var)),
                        Err(var_err) => {
                            match TryIntoRef::<T>::try_into_ref(&token) {
                                Ok(op) => Ok(Arithm::Operand(op)),
                                Err(op_err) => Err(ExprResult::InvalidToken {
                                    evaluator: eval_err,
                                    variable: var_err,
                                    operand: op_err,
                                })
                            }
                        }
                    }
                }
            }
        }).collect();
        final_expr.and_then(|final_expr| {
            match Expression::check_validity(&final_expr) {
                Ok(_) => Ok(Expression {
                    max_stack: Expression::compute_stack_max(&final_expr),
                    expr: final_expr
                }),
                Err(err) => Err(ExprResult::OperandErr(err)),
            }
        })
    }
}

/// Used to specify the error during the conversion.
#[derive(Debug, PartialEq)]
pub enum ExprResult<A, B, C> {
    OperandErr(OperandErr),
    InvalidToken {
        evaluator: A,
        variable: B,
        operand: C
    },
}

/// Used to specify an error related to wrong number of operands in expression.
#[derive(Debug, PartialEq)]
pub enum OperandErr {
    TooManyOperands,
    NotEnoughOperand,
}

impl<T, V, E: Evaluate<T>> Expression<T, V, E> {
{'fraction_non_alphanumeric': 0.14667728720983159, 'fraction_numerical': 0.0004551661356395084, 'mean_word_length': 1.8572821846553966, 'pattern_counts': {'":': 0, '<': 85, '<?xml version=': 0, '>': 113, 'https://': 4, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 18, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '4356443', 'n_tokens_mistral': 2665, 'n_tokens_neox': 2609, 'n_words': 590}