ScopeManager

Defined in: packages/engine/src/vm/ScopeManager.ts:24

Scoped variable manager for expression evaluation.

Tracks variable definitions across line numbers with write-on-read semantics. When a value is read, the most recent definition at or before the reading line is returned. Invalidation trims downstream definitions when a variable is redefined.

Constructors

Constructor

new ScopeManager(): ScopeManager;

Returns

ScopeManager

Methods

clear()

clear(): void;

Defined in: packages/engine/src/vm/ScopeManager.ts:74

Remove every tracked variable definition, used when an engine/document is reset.

Returns

void

---

invalidateDownstream()

invalidateDownstream(variable, definitionLine): void;

Defined in: packages/engine/src/vm/ScopeManager.ts:65

Drop every definition of variable that comes strictly after definitionLine. Call this when a line is re-evaluated with a new definition, so stale later-line definitions from a previous edit don’t linger and get returned by read.

Parameters

Parameter	Type
variable	string
definitionLine	number

Returns

void

---

read()

read(variable, readLine): Value | undefined;

Defined in: packages/engine/src/vm/ScopeManager.ts:50

Look up a variable’s value as seen from readLine: returns the result of the closest definition at or before readLine, not simply the most recently-written one, so a read on line 5 of a variable redefined on lines 2 and 10 sees line 2’s value, not line 10’s. Returns undefined if the variable has no definition at or before readLine.

Parameters

Parameter	Type
variable	string
readLine	number

Returns

Value | undefined

---

write()

write(
   variable,
   lineNumber,
   expr): void;

Defined in: packages/engine/src/vm/ScopeManager.ts:34

Record a variable definition at lineNumber. A variable may have multiple definitions across different lines (e.g. redefined further down a document), each call adds one, keeping the internal stack sorted by line so read can binary-scan for “most recent definition at or before” a given line.

Parameters

Parameter	Type
variable	string
lineNumber	number
expr	ExpressionRecord

Returns

void