Struct clingo::Symbol

pub struct Symbol(_);

Represents a symbol.

This includes numbers, strings, functions (including constants when arguments are empty and tuples when the name is empty), #inf and #sup.

Methods

impl Symbol

pub fn create_number(number: i32) -> Symbol

Construct a symbol representing a number.

pub fn create_supremum() -> Symbol

Construct a symbol representing #sup.

pub fn create_infimum() -> Symbol

Construct a symbol representing #inf

pub fn create_string(string: &str) -> Result<Symbol, Error>

Construct a symbol representing a string.

Arguments

• string - the string

Errors:

• NulError - if string contains a nul byte
• ErrorType::BadAlloc

pub fn create_id(name: &str, positive: bool) -> Result<Symbol, Error>

Construct a symbol representing an id.

Note: This is just a shortcut for create_function() with empty arguments.

Arguments

• name - the name of the symbol
• positive - whether the symbol has a classical negation sign

Errors

• NulError - if name contains a nul byte
• ErrorType::BadAlloc

pub fn create_function(
    name: &str,
    arguments: &[Symbol],
    positive: bool
) -> Result<Symbol, Error>

Construct a symbol representing a function or tuple.

Note: To create tuples, the empty string has to be used as name.

Arguments

• name - the name of the function
• arguments - the arguments of the function
• positive - whether the symbol has a classical negation sign

Errors

• NulError - if name contains a nul byte
• ErrorType::BadAlloc

pub fn number(&self) -> Result<i32, ClingoError>

Get the number of a symbol.

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::Number

pub fn name(&self) -> Result<&str, Error>

Get the name of a symbol.

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::Function
• Utf8Error

pub fn string(&self) -> Result<&str, Error>

Get the string of a symbol.

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::String
• Utf8Error

pub fn is_positive(&self) -> Result<bool, ClingoError>

Check if a function is positive (does not have a sign).

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::Function

pub fn is_negative(&self) -> Result<bool, ClingoError>

Check if a function is negative (has a sign).

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::Function

pub fn arguments(&self) -> Result<Vec<Symbol>, ClingoError>

Get the arguments of a symbol.

Errors

• ErrorType::Runtime if symbol is not of type SymbolType::Function

pub fn symbol_type(&self) -> SymbolType

Get the type of a symbol.

Errors

• may failed to match clingo symbol type

pub fn to_string(&self) -> Result<String, Error>

Get the string representation of a symbol.

Errors

• ErrorType::BadAlloc
• Utf8Error

Trait Implementations

impl Debug for Symbol

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Copy for Symbol

impl Clone for Symbol

fn clone(&self) -> Symbol

Returns a copy of the value.

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

Performs copy-assignment from source.

impl PartialEq for Symbol

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

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

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

This method tests for !=.

impl Eq for Symbol

impl PartialOrd for Symbol

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

Compare two symbols.

Symbols are first compared by type. If the types are equal, the values are compared (where strings are compared using strcmp). Functions are first compared by signature and then lexicographically by arguments.

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 Hash for Symbol

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

Calculate a hash code of a symbol.

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

Feeds a slice of this type into the given [Hasher].