Struct TrackedExpressionAttributes 

pub struct TrackedExpressionAttributes<'a> {
    pub names: &'a Option<HashMap<String, String>>,
    pub values: &'a Option<HashMap<String, AttributeValue>>,
    /* private fields */
}

Wrapper around expression attribute names/values that tracks which entries are used.

Use RefCell for interior mutability so it can be passed as &TrackedExpressionAttributes (not &mut) through all expression evaluation functions.

Fields

names: &'a Option<HashMap<String, String>>

values: &'a Option<HashMap<String, AttributeValue>>

Implementations

impl<'a> TrackedExpressionAttributes<'a>

pub fn new( names: &'a Option<HashMap<String, String>>, values: &'a Option<HashMap<String, AttributeValue>>, ) -> Self

pub fn without_tracking( names: &'a Option<HashMap<String, String>>, values: &'a Option<HashMap<String, AttributeValue>>, ) -> Self

Create a variant that skips tracking. Name/value resolution still works but HashSet insertions are skipped. Use in hot loops where tracking has already been done by track_condition_expr pre-loop.

pub fn resolve_name(&self, name: &str) -> Result<String, String>

Resolve an attribute name, handling #name substitution, and track usage.

pub fn resolve_value<'b>( &'b self, name: &str, ) -> Result<&'a AttributeValue, String>

Resolve an attribute value reference :name and track usage.

pub fn track_condition_expr(&self, expr: &ConditionExpr)

Pre-register all #name and :value references found in a parsed condition expression. This ensures they are tracked even if the expression is never evaluated (e.g., no items).

pub fn track_projection_expr(&self, proj: &ProjectionExpr)

Pre-register all #name references found in a parsed projection expression.

pub fn track_update_expr(&self, expr: &UpdateExpr)

Pre-register all #name and :value references found in a parsed update expression.

pub fn track_key_condition(&self, cond: &KeyCondition)

Pre-register all #name and :value references in a parsed key condition. Note: key_condition::parse already resolves names, so we track the original value refs that will be resolved later via resolve_values.

pub fn check_unused(&self) -> Result<(), DynoxideError>

Check for unused names/values. Returns an error listing all unused keys.