Struct parol::grammar::production::Pr

pub struct Pr(pub Symbol, pub Rhs);

Production type

Tuple Fields

0: Symbol

1: Rhs

Implementations

impl Pr

pub fn new(n: &str, r: Rhs) -> Self

pub fn get_n(&self) -> String

pub fn get_n_str(&self) -> &str

pub fn get_r(&self) -> &Rhs

pub fn get_r_mut(&mut self) -> &mut Rhs

pub fn take(self) -> (String, Rhs)

pub fn set_n(&mut self, n: String)

pub fn set_r(&mut self, r: Rhs)

pub fn is_empty(&self) -> bool

pub fn len(&self) -> usize

pub fn first_len(&self) -> usize

Calculates the length of the terminal symbols at the beginning of the RHS.

use parol::{Pr, Symbol};

let pr = Pr::new("S", vec![]);
assert_eq!(0, pr.first_len());
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::n("L")]);
assert_eq!(0, pr.first_len());
let pr = Pr::new("S", vec![Symbol::n("I"), Symbol::n("L")]);
assert_eq!(0, pr.first_len());
let pr = Pr::new("S", vec![Symbol::t(","), Symbol::n("N")]);
assert_eq!(1, pr.first_len());
let pr = Pr::new("S", vec![Symbol::t("d")]);
assert_eq!(1, pr.first_len());
let pr = Pr::new("S", vec![Symbol::t("d"), Symbol::t("e")]);
assert_eq!(2, pr.first_len());

pub fn first_len_at(&self, sy_idx: usize) -> usize

Calculates the length of the terminal symbols starting from an offset within the RHS.

use parol::{Pr, Symbol};

let pr = Pr::new("S", vec![]);
assert_eq!(0, pr.first_len_at(0));
assert_eq!(0, pr.first_len_at(1));
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::n("L")]);
assert_eq!(0, pr.first_len_at(0));
assert_eq!(0, pr.first_len_at(1));
assert_eq!(0, pr.first_len_at(2));
assert_eq!(0, pr.first_len_at(3));
let pr = Pr::new("S", vec![Symbol::t(","), Symbol::n("N")]);
assert_eq!(1, pr.first_len_at(0));
assert_eq!(0, pr.first_len_at(1));
assert_eq!(0, pr.first_len_at(2));
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::t("d"), Symbol::t("e")]);
assert_eq!(0, pr.first_len_at(0));
assert_eq!(2, pr.first_len_at(1));
assert_eq!(1, pr.first_len_at(2));
assert_eq!(0, pr.first_len_at(3));
let pr = Pr::new("S", vec![Symbol::t("c"), Symbol::t("d"), Symbol::t("e")]);
assert_eq!(3, pr.first_len_at(0));
assert_eq!(2, pr.first_len_at(1));
assert_eq!(1, pr.first_len_at(2));
assert_eq!(0, pr.first_len_at(3));
let pr = Pr::new("S", vec![Symbol::t("c"), Symbol::t("d"), Symbol::t("e"), Symbol::n("N")]);
assert_eq!(3, pr.first_len_at(0));
assert_eq!(2, pr.first_len_at(1));
assert_eq!(1, pr.first_len_at(2));
assert_eq!(0, pr.first_len_at(3));
assert_eq!(0, pr.first_len_at(4));

pub fn is_k_derivable(&self, k: usize) -> bool

Calculates whether a next derivation is necessary and possible to get a first length of k. If the first_len is already equal or greater than k there is no derivation necessary. Else if no non-terminal is contained then a derivation is not possible Else it returns true.

use parol::{Pr, Symbol};

let pr = Pr::new("S", vec![]);
assert!(!pr.is_k_derivable(1), "Empty production - not possible");
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::n("L")]);
assert!(pr.is_k_derivable(1), "k_len == 0 but containing Nt - possible");
let pr = Pr::new("S", vec![Symbol::t(","), Symbol::n("N")]);
assert!(!pr.is_k_derivable(1), "k_len == 1 - not necessary");
assert!(pr.is_k_derivable(2), "k_len == 1 but containing Nt - not necessary");
let pr = Pr::new("S", vec![Symbol::t("d")]);
assert!(!pr.is_k_derivable(1), "k_len == 1 - not necessary");
assert!(!pr.is_k_derivable(2), "k_len == 1, containing no Nt - not possible");
let pr = Pr::new("S", vec![Symbol::t("d"), Symbol::t("e")]);
assert!(!pr.is_k_derivable(1), "k_len == 2 - not necessary");
assert!(!pr.is_k_derivable(2), "k_len == 2 - not necessary");
assert!(!pr.is_k_derivable(3), "k_len == 2, containing no Nt - not possible");

pub fn is_k_derivable_at(&self, k: usize, sy_idx: usize) -> bool

Calculates whether a next derivation is necessary and possible to get a first length of k at a given symbol offset. If the first_len_at is already equal or greater than k there is no derivation necessary. Else if no non-terminal is contained then a derivation is not possible Else it returns true.

use parol::{Pr, Symbol};

let pr = Pr::new("S", vec![]);
assert!(!pr.is_k_derivable_at(1, 0), "Empty production - not possible");
assert!(!pr.is_k_derivable_at(1, 1), "Empty production, invalid index - not possible");
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::n("L")]);
assert!(pr.is_k_derivable_at(1, 0), "k_len == 0 but containing Nt - possible");
assert!(pr.is_k_derivable_at(1, 1), "k_len == 0 but containing Nt - possible");
assert!(!pr.is_k_derivable_at(1, 2), "invalid index - not possible");
let pr = Pr::new("S", vec![Symbol::t(","), Symbol::n("N")]);
assert!(!pr.is_k_derivable_at(1, 0), "k_len == 1 - not necessary");
assert!(pr.is_k_derivable_at(2, 0), "k_len == 1 but containing Nt - possible");
assert!(pr.is_k_derivable_at(2, 1), "k_len == 0 but containing Nt - possible");
assert!(!pr.is_k_derivable_at(2, 2), "invalid index - not possible");
let pr = Pr::new("S", vec![Symbol::t("d")]);
assert!(!pr.is_k_derivable_at(1, 0), "k_len == 1 - not necessary");
assert!(!pr.is_k_derivable_at(2, 0), "k_len == 1, containing no Nt - not possible");
assert!(!pr.is_k_derivable_at(1, 1), "invalid index - not possible");
assert!(!pr.is_k_derivable_at(2, 1), "invalid index - not possible");
let pr = Pr::new("S", vec![Symbol::t("d"), Symbol::t("e")]);
assert!(!pr.is_k_derivable_at(1, 0), "k_len == 2 - not necessary");
assert!(!pr.is_k_derivable_at(2, 0), "k_len == 2 - not necessary");
assert!(!pr.is_k_derivable_at(3, 0), "k_len == 2, containing no Nt - not possible");
assert!(!pr.is_k_derivable_at(1, 1), "k_len == 1 - not necessary");
assert!(!pr.is_k_derivable_at(2, 1), "k_len == 1 - not possible");
assert!(!pr.is_k_derivable_at(3, 1), "invalid index - not possible");

pub fn is_valid_index(&self, idx: usize) -> bool

pub fn try_get_rhs_symbol(&self, sy_index: usize) -> Option<&Symbol>

Trait Implementations

impl Clone for Pr

fn clone(&self) -> Pr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Pr

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

Formats the value using the given formatter.

impl Default for Pr

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Pr

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Display for Pr

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

The output format for a production roughly follows the Yacc format.

use parol::{Pr, Symbol};

let pr = Pr::new("S", vec![]);
assert_eq!("S: ;", format!("{}", pr));
let pr = Pr::new("S", vec![Symbol::n("N"), Symbol::n("L")]);
assert_eq!("S: N L;", format!("{}", pr));
let pr = Pr::new("S", vec![Symbol::n("I"), Symbol::n("L")]);
assert_eq!("S: I L;", format!("{}", pr));
let pr = Pr::new("S", vec![Symbol::t(","), Symbol::n("N")]);
assert_eq!(r#"S: "," N;"#, format!("{}", pr));
let pr = Pr::new("S", vec![Symbol::t("d")]);
assert_eq!(r#"S: "d";"#, format!("{}", pr));
let pr = Pr::new("S", vec![Symbol::t(r#"\d"#), Symbol::t("e")]);
assert_eq!(r#"S: "\d" "e";"#, format!("{}", pr));

impl Hash for Pr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Index<usize> for Pr

type Output = Symbol

The returned type after indexing.

fn index(&self, idx: usize) -> &Self::Output

Performs the indexing (container[index]) operation.

impl Ord for Pr

fn cmp(&self, other: &Pr) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Pr> for Pr

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

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

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

This method tests for !=.

impl PartialOrd<Pr> for Pr

fn partial_cmp(&self, other: &Pr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Pr

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl Eq for Pr

impl StructuralEq for Pr

impl StructuralPartialEq for Pr