/
UnaryExpression.ts
65 lines (58 loc) · 2.12 KB
/
UnaryExpression.ts
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import { DeoptimizableEntity } from '../DeoptimizableEntity';
import { HasEffectsContext } from '../ExecutionContext';
import { EMPTY_PATH, ObjectPath, PathTracker } from '../utils/PathTracker';
import Identifier from './Identifier';
import { LiteralValue } from './Literal';
import * as NodeType from './NodeType';
import { LiteralValueOrUnknown, UnknownValue } from './shared/Expression';
import { ExpressionNode, NodeBase } from './shared/Node';
const unaryOperators: {
[operator: string]: (value: LiteralValue) => LiteralValueOrUnknown;
} = {
'!': value => !value,
'+': value => +(value as NonNullable<LiteralValue>),
'-': value => -(value as NonNullable<LiteralValue>),
delete: () => UnknownValue,
typeof: value => typeof value,
void: () => undefined,
'~': value => ~(value as NonNullable<LiteralValue>)
};
export default class UnaryExpression extends NodeBase {
argument!: ExpressionNode;
operator!: '!' | '+' | '-' | 'delete' | 'typeof' | 'void' | '~';
prefix!: boolean;
type!: NodeType.tUnaryExpression;
protected deoptimized = false;
getLiteralValueAtPath(
path: ObjectPath,
recursionTracker: PathTracker,
origin: DeoptimizableEntity
): LiteralValueOrUnknown {
if (path.length > 0) return UnknownValue;
const argumentValue = this.argument.getLiteralValueAtPath(EMPTY_PATH, recursionTracker, origin);
if (argumentValue === UnknownValue) return UnknownValue;
return unaryOperators[this.operator](argumentValue);
}
hasEffects(context: HasEffectsContext): boolean {
if (!this.deoptimized) this.applyDeoptimizations();
if (this.operator === 'typeof' && this.argument instanceof Identifier) return false;
return (
this.argument.hasEffects(context) ||
(this.operator === 'delete' &&
this.argument.hasEffectsWhenAssignedAtPath(EMPTY_PATH, context))
);
}
hasEffectsWhenAccessedAtPath(path: ObjectPath): boolean {
if (this.operator === 'void') {
return path.length > 0;
}
return path.length > 1;
}
protected applyDeoptimizations(): void {
this.deoptimized = true;
if (this.operator === 'delete') {
this.argument.deoptimizePath(EMPTY_PATH);
this.context.requestTreeshakingPass();
}
}
}