Struct ValueTable 

pub struct ValueTable { /* private fields */ }

Bidirectional mapping between normalised expressions and value numbers.

The “key” is a NormExpr — a lightweight structural hash of the expression that only depends on the value numbers of sub-expressions (rather than variable ids). This makes it insensitive to renaming.

Implementations

impl ValueTable

pub fn new() -> Self

pub fn lookup(&self, key: &NormExpr) -> Option<ValueNumber>

Look up the value number for a normalised expression key.

pub fn canonical_var(&self, vn: ValueNumber) -> Option<LcnfVarId>

Return the canonical variable for a value number, if one exists.

pub fn insert( &mut self, key: NormExpr, value: LcnfLetValue, var: LcnfVarId, ) -> ValueNumber

Insert a new expression with a fresh value number, binding var as its canonical representative. Returns the assigned VN.

pub fn len(&self) -> usize

Total number of value numbers assigned so far.

pub fn is_empty(&self) -> bool

pub fn snapshot(&self) -> Vec<(NormExpr, ValueNumber)>

Return a snapshot of all (NormExpr, VN) pairs.

pub fn try_merge(&mut self, other: &ValueTable) -> bool

Attempt to merge the entries from other into self without conflict (returns false on any VN collision).

Trait Implementations

impl Clone for ValueTable

fn clone(&self) -> ValueTable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ValueTable

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

Formats the value using the given formatter.

impl Default for ValueTable

fn default() -> ValueTable

Returns the “default value” for a type.