Struct bnf::Expression

pub struct Expression { /* fields omitted */ }

An Expression is comprised of any number of Terms

Methods

impl Expression

pub fn new() -> Expression

Construct a new Expression

pub fn from_parts(v: Vec<Term>) -> Expression

Construct an Expression from Terms

pub fn from_str(s: &str) -> Result<Self, Error>

pub fn add_term(&mut self, term: Term)

Add Term to Expression

pub fn remove_term(&mut self, term: &Term) -> Option<Term>

Remove Term from Expression

If interested if Term was removed, then inspect the returned Option.

Example

extern crate bnf;
use bnf::{Expression, Term};

fn main() {
    let mut expression = Expression::from_parts(vec![]);
    let to_remove = Term::Terminal(String::from("a_terminal"));
    let removed = expression.remove_term(&to_remove);
    match removed {
        Some(term) => println!("removed {}", term),
        None => println!("term was not in expression, so could not be removed"),
    }

}

pub fn terms_iter(&self) -> Iter

Get iterator of Terms within Expression

pub fn terms_iter_mut(&mut self) -> IterMut

Get mutable iterator of Terms within Expression

Trait Implementations

impl PartialEq<Expression> for Expression

fn eq(&self, other: &Expression) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Expression) -> bool

This method tests for !=.

impl Clone for Expression

fn clone(&self) -> Expression

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Expression

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Display for Expression

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl FromStr for Expression

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.