Struct exprtk_rs::SymbolTable

pub struct SymbolTable { /* fields omitted */ }

SymbolTable holds different variables. There are three types of variables: Numberic variables, strings and numeric vectors of fixed size. (see the documentation). Many but not all of the methods of the ExprTk symbol_table were implemented, and the API is sometimes different.

Methods

impl SymbolTable

pub fn new() -> SymbolTable

pub fn add_constant(     &mut self,     name: &str,     value: c_double ) -> Result<bool, InvalidName>

pub fn add_variable(     &mut self,     name: &str,     value: c_double ) -> Result<Option<usize>, InvalidName>

Adds a new variable. Returns the variable ID that can later be used for set_value or None if a variable with the same name was already present.

pub fn set_value(&mut self, var_id: usize, value: c_double) -> bool

pub fn value(&self, var_id: usize) -> Option<&c_double>

pub fn get_value_ptr(&self, var_id: usize) -> Option<*mut c_double>

Allows setting the values directly in an unsafe block, which may be useful, e.g. when benchmarking

Example:

use exprtk_rs::*;

let mut symbol_table = SymbolTable::new();
let id = symbol_table.add_variable("a", 2.).unwrap().unwrap();
let ptr = symbol_table.get_value_ptr(id).unwrap();
let expr = Expression::new("a - 1", symbol_table).unwrap();
assert_eq!(expr.value(), 1.);

unsafe {
    *ptr = 4.;
}
assert_eq!(expr.value(), 3.);

pub fn mut_value(&mut self, var_id: usize) -> Option<&mut c_double>

pub fn add_stringvar(     &mut self,     name: &str,     text: &[u8] ) -> Result<Option<usize>, InvalidName>

Adds a new string variable. Returns the variable ID that can later be used for set_string or None if a variable with the same name was already present.

pub fn set_string(&mut self, var_id: usize, text: &[u8]) -> bool

pub fn string(&self, var_id: usize) -> Option<&StringValue>

pub fn mut_string(&mut self, var_id: usize) -> Option<&mut StringValue>

pub fn add_vector(     &mut self,     name: &str,     vec: &[c_double] ) -> Result<Option<usize>, InvalidName>

Adds a new vector variable. Returns the variable ID that can later be used for vector or None if a variable with the same name was already present.

pub fn vector(&self, var_id: usize) -> Option<&[c_double]>

pub fn mut_vector(&mut self, var_id: usize) -> Option<&mut [c_double]>

pub fn get_var_id(&self, name: &str) -> Option<usize>

Returns the 'ID' of a variable or None if not found

pub fn get_string_id(&self, name: &str) -> Option<usize>

Returns the 'ID' of a string or None if not found

pub fn get_vec_id(&self, name: &str) -> Option<usize>

Returns the 'ID' of a vector or None if not found

pub fn clear_variables(&mut self)

pub fn clear_strings(&mut self)

pub fn clear_vectors(&mut self)

pub fn variable_count(&self) -> usize

pub fn stringvar_count(&self) -> usize

pub fn vector_count(&self) -> usize

pub fn add_constants(&self) -> bool

pub fn add_pi(&self) -> bool

pub fn add_epsilon(&self) -> bool

pub fn add_infinity(&self) -> bool

Important traits for Vec<u8>

impl Write for Vec<u8>

pub fn get_variable_names(&self) -> Vec<String>

Important traits for Vec<u8>

impl Write for Vec<u8>

pub fn get_stringvar_names(&self) -> Vec<String>

Important traits for Vec<u8>

impl Write for Vec<u8>

pub fn get_vector_names(&self) -> Vec<String>

pub fn symbol_exists(&self, name: &str) -> bool

pub fn is_constant_node(&self, name: &str) -> bool

pub fn is_constant_string(&self, name: &str) -> bool

impl SymbolTable

pub fn add_func1<F>(&mut self, name: &str, func: F) -> Result<bool, InvalidName> where     F: Fn(c_double) -> c_double,

Add a function. Returns true if the function was added / false if the name was already present.

impl SymbolTable

pub fn add_func2<F>(&mut self, name: &str, func: F) -> Result<bool, InvalidName> where     F: Fn(c_double, c_double) -> c_double,

Add a function. Returns true if the function was added / false if the name was already present.

impl SymbolTable

pub fn add_func3<F>(&mut self, name: &str, func: F) -> Result<bool, InvalidName> where     F: Fn(c_double, c_double, c_double) -> c_double,

Add a function. Returns true if the function was added / false if the name was already present.

impl SymbolTable

pub fn add_func4<F>(&mut self, name: &str, func: F) -> Result<bool, InvalidName> where     F: Fn(c_double, c_double, c_double, c_double) -> c_double,

Add a function. Returns true if the function was added / false if the name was already present.

Trait Implementations

impl Send for SymbolTable

impl Drop for SymbolTable

fn drop(&mut self)

Executes the destructor for this type.

impl Debug for SymbolTable

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

Formats the value using the given formatter.

impl Clone for SymbolTable

fn clone(&self) -> SymbolTable

Returns a copy of the value.

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

Performs copy-assignment from source.