Struct SymTable 

pub struct SymTable { /* private fields */ }

Symbol table containing constants and functions.

The table stores mathematical constants like pi and functions like sin. Symbol lookups are case-insensitive.

Examples

use expr_solver::SymTable;
use rust_decimal_macros::dec;

let mut table = SymTable::stdlib();
table.add_const("x", dec!(42)).unwrap();

Implementations

impl SymTable

pub fn new() -> Self

Creates an empty symbol table.

pub fn stdlib() -> Self

Creates a symbol table with the standard library.

Constants

• pi - π (3.14159…)
• e - Euler’s number (2.71828…)
• tau - 2π (6.28318…)
• ln2 - Natural logarithm of 2
• ln10 - Natural logarithm of 10
• sqrt2 - Square root of 2

Fixed arity functions

• sin(x) - Sine
• cos(x) - Cosine
• tan(x) - Tangent
• asin(x) - Arcsine
• acos(x) - Arccosine
• atan(x) - Arctangent
• atan2(y, x) - Two-argument arctangent
• sinh(x) - Hyperbolic sine
• cosh(x) - Hyperbolic cosine
• tanh(x) - Hyperbolic tangent
• sqrt(x) - Square root
• cbrt(x) - Cube root
• pow(x, y) - x raised to power y
• log(x) - Natural logarithm
• log2(x) - Base-2 logarithm
• log10(x) - Base-10 logarithm
• exp(x) - e raised to power x
• exp2(x) - 2 raised to power x
• abs(x) - Absolute value
• sign(x) - Sign function (-1, 0, or 1)
• floor(x) - Floor function
• ceil(x) - Ceiling function
• round(x) - Round to nearest integer
• trunc(x) - Truncate to integer
• fract(x) - Fractional part
• mod(x, y) - Remainder of x/y
• hypot(x, y) - Euclidean distance sqrt(x²+y²)
• clamp(x, min, max) - Constrain value between bounds

Variadic functions

• min(x, ...) - Minimum value
• max(x, ...) - Maximum value
• sum(x, ...) - Sum of values
• avg(x, ...) - Average of values

pub fn add_const<S: Into<Cow<'static, str>>>( &mut self, name: S, value: Decimal, ) -> Result<&mut Self, SymbolError>

Adds a constant to the table.

Returns an error if a symbol with the same name already exists.

pub fn add_func<S: Into<Cow<'static, str>>>( &mut self, name: S, args: usize, variadic: bool, callback: fn(&[Decimal]) -> Result<Decimal, FuncError>, ) -> Result<&mut Self, SymbolError>

Adds a function to the table.

Parameters

• name: Function name
• args: Minimum number of arguments
• variadic: Whether the function accepts additional arguments
• callback: Function implementation

Returns an error if a symbol with the same name already exists.

pub fn get(&self, name: &str) -> Option<&Symbol>

Looks up a symbol by name (case-insensitive).

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

Looks up a symbol by name and returns its index and reference (case-insensitive).

pub fn get_by_index(&self, index: usize) -> Option<&Symbol>

Returns a symbol by index.

pub fn symbols(&self) -> impl Iterator<Item = &Symbol>

Returns an iterator over all symbols in the table.

Trait Implementations

impl Clone for SymTable

fn clone(&self) -> SymTable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SymTable

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

Formats the value using the given formatter.

impl Default for SymTable

fn default() -> SymTable

Returns the “default value” for a type.