Enum Expression 

pub enum Expression {
    Lit(i64),
    Var(Reference),
    BinOp {
        op: ArithOp,
        lhs: Box<Expression>,
        rhs: Box<Expression>,
    },
    Pow {
        base: Box<Expression>,
        exp: Box<Expression>,
    },
    FnCall {
        name: Ident,
        args: Vec<Expression>,
    },
}

Expression in constraints — represents numeric formulas.

Rev.1: 5 variants replacing the old 4. Lit/Var/BinOp/Pow/FnCall.

Variants

Lit(i64)

Integer literal: 1, 42, 1000000007.

Var(Reference)

Variable reference, such as N or A[i].

BinOp

Binary arithmetic: lhs op rhs.

Fields

op: ArithOp

lhs: Box<Expression>

rhs: Box<Expression>

Pow

Power: base^exp (e.g., 10^9, 2^30).

Fields

base: Box<Expression>

exp: Box<Expression>

FnCall

Function call: min(a,b), max(a,b), abs(x), len(arr).

Fields

name: Ident

args: Vec<Expression>

Implementations

impl Expression

pub fn evaluate_constant(&self) -> Option<i64>

Evaluate to a constant if possible (no variable references).

Trait Implementations

impl Clone for Expression

fn clone(&self) -> Expression

Returns a duplicate 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 PartialEq for Expression

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Expression