Fixed empty {} not handled. Added simple nested test

README.md

@@ -25,7 +25,8 @@ For certain applications, documentation may be of much greater importance than c
 ## Usage
 
 ```cs
-yarn add mation-spec@https://github.com/fuzzthink/mation-spec/tarball/v0.1.4  // For now
+yarn add mation-spec@https://github.com/fuzzthink/mation-spec/tarball/<latest> // For now
+  //  where <latest> is eg. v0.1.5, see Releases for latest
 yarn add 'mation-spec' // When package is published
 ```
 

src/api.js

@@ -33,14 +33,16 @@ mationGrammar {
   KeyValues = (KeyValue ","?)+ //> ","?  // Nonempty needed for + on parent
   KeyValue = Key ":" Value
   Map = "{" KeyValues "}"
-
+  EmptyMap = "{" "}" // can't be lexical rule
+  
   Key
     = identifier
     | stringLiteral
     | numericLiteral
   Value
     = KeyValue
     | Map
+    | EmptyMap
     | identifier
     | literal
     | List

src/mationGrammar.ohm

@@ -4,6 +4,7 @@ mationGrammar {
   KeyValues = (KeyValue ","?)+ //> ","?  // Nonempty needed for + on parent
   KeyValue = Key ":" Value
   Map = "{" KeyValues "}"
+  EmptyMap = "{" "}" // can't be lexical rule
 
   Key
     = identifier
@@ -12,6 +13,7 @@ mationGrammar {
   Value
     = KeyValue
     | Map
+    | EmptyMap
     | identifier
     | literal
     | List

src/parser.js

@@ -21,7 +21,7 @@ parse.literal = (literal={}) => {
     case 'stringLiteral':
       return sourceString.slice(1, -1)
   }
-  throw new Error(`Handler missing for literal of type: ${ctorName}`)
+  throw new Error(`Parser missing handler for literal of type: ${ctorName}`)
 }
 
 parse.List = (iter={}) => {
@@ -65,8 +65,10 @@ parse.Value = (node={}) => {
       return parse.KeyValue(node.child(0), node.child(2))
     case 'Map':
       return parse.Map(node)
+    case 'EmptyMap':
+      return {}
   }
-  throw new Error(`Handler missing for Value of type: ${node.ctorName}`)
+  throw new Error(`Parser missing handler for Value of type: ${node.ctorName}`)
 }
 
 parse.Command = (Command={}) => {

test/nested.test.js

@@ -0,0 +1,35 @@
+import { test, expect } from 'vitest'
+import { parse } from '../src/api'
+
+test(`Nested - Mostly emtpy structures, with good mix of comma/no-comma`, () => {
+  expect(parse(`
+    /** md **
+     */
+    model: {
+      dimensions: letter
+      creases: {
+        method: acrossPoints
+        valueType: index,
+        values: [
+          [0 1] //1
+        ]
+      },
+    },
+    tweenDuration: {
+    }
+    steps: [
+    ]
+  `).result)
+  .toStrictEqual({
+    model: {
+      dimensions: 'letter',
+      creases: {
+        method: 'acrossPoints',
+        valueType: 'index',
+        values: [[0, 1]],
+      },
+    },
+    tweenDuration: {},
+    steps: [],
+  })
+})