@atomic-ehr/fhirpath/src/operations/dot-operator.ts

A TypeScript implementation of FHIRPath

import type { OperatorDefinition } from '../types';
import { Errors } from '../errors';
import { PRECEDENCE } from '../types';
import type { OperationEvaluator } from '../types';
import { box, unbox } from '../boxing';

// Note: The dot operator is special and is typically handled directly in the interpreter
// because it needs to evaluate its operands in sequence, not in parallel
export const evaluate: OperationEvaluator = async (input, context, left, right) => {
  // This should not be called directly - dot operator needs special handling
  // in the interpreter to properly sequence evaluation
  throw Errors.invalidOperation('Dot operator requires special handling in the interpreter');
};

export const dotOperator: OperatorDefinition & { evaluate: OperationEvaluator } = {
  symbol: '.',
  name: 'dot',
  category: ['navigation'],
  precedence: PRECEDENCE.DOT,
  associativity: 'left',
  description: 'Navigation operator',
  examples: ['Patient.name.given'],
  signatures: [
    {
      name: 'navigation',
      left: { type: 'Any', singleton: false },
      right: { type: 'Any', singleton: false },
      result: { type: 'Any', singleton: false }
    },
    {
      name: 'navigation-singleton',
      left: { type: 'Any', singleton: true },
      right: { type: 'Any', singleton: false },
      result: { type: 'Any', singleton: false }
    }
  ],
  evaluate
};