Add option to include ordinal keys in plz unparsers

This isn't used by either the pretty or inline plz unparsers, but
makes it easier to experiment with alternative formats.

Author: mkantor

src/language/unparsing/inline-plz.ts

@@ -3,9 +3,9 @@ import type { Atom, Molecule } from '../parsing.js'
 import {
   closeBrace,
   comma,
+  moleculeAsKeyValuePairStrings,
   moleculeUnparser,
   openBrace,
-  sugarFreeMoleculeAsKeyValuePairStrings,
   unparseAtom,
 } from './plz-utilities.js'
 import type { Notation } from './unparsing-utilities.js'
@@ -15,7 +15,9 @@ const unparseSugarFreeMolecule = (value: Molecule) => {
     return either.makeRight(openBrace + closeBrace)
   } else {
     return either.map(
-      sugarFreeMoleculeAsKeyValuePairStrings(value, unparseAtomOrMolecule),
+      moleculeAsKeyValuePairStrings(value, unparseAtomOrMolecule, {
+        ordinalKeys: 'omit',
+      }),
       keyValuePairsAsStrings =>
         openBrace
           .concat(' ')

src/language/unparsing/plz-utilities.ts

@@ -78,9 +78,10 @@ export const serializeIfNeeded = (
     ? serialize(nodeOrMolecule)
     : either.makeRight(nodeOrMolecule)
 
-export const sugarFreeMoleculeAsKeyValuePairStrings = (
+export const moleculeAsKeyValuePairStrings = (
   value: Molecule,
   unparseAtomOrMolecule: UnparseAtomOrMolecule,
+  options: { readonly ordinalKeys: 'omit' | 'preserve' },
 ): Either<UnserializableValueError, readonly string[]> => {
   const entries = Object.entries(value)
 
@@ -93,7 +94,10 @@ export const sugarFreeMoleculeAsKeyValuePairStrings = (
     }
 
     // Omit ordinal property keys:
-    if (propertyKey === String(ordinalPropertyKeyCounter)) {
+    if (
+      propertyKey === String(ordinalPropertyKeyCounter) &&
+      options.ordinalKeys === 'omit'
+    ) {
       keyValuePairsAsStrings.push(valueAsStringResult.value)
       ordinalPropertyKeyCounter += 1n
     } else {

src/language/unparsing/pretty-plz.ts

@@ -2,9 +2,9 @@ import either from '@matt.kantor/either'
 import type { Atom, Molecule } from '../parsing.js'
 import {
   closeBrace,
+  moleculeAsKeyValuePairStrings,
   moleculeUnparser,
   openBrace,
-  sugarFreeMoleculeAsKeyValuePairStrings,
   unparseAtom,
 } from './plz-utilities.js'
 import { indent, type Notation } from './unparsing-utilities.js'
@@ -14,7 +14,9 @@ const unparseSugarFreeMolecule = (value: Molecule) => {
     return either.makeRight(openBrace + closeBrace)
   } else {
     return either.map(
-      sugarFreeMoleculeAsKeyValuePairStrings(value, unparseAtomOrMolecule),
+      moleculeAsKeyValuePairStrings(value, unparseAtomOrMolecule, {
+        ordinalKeys: 'omit',
+      }),
       keyValuePairsAsStrings =>
         openBrace
           .concat('\n')