Add support for matching some keys of an object against corresponding…

… rules
balena-io-modules · Jun 11, 2016 · bff277a · bff277a
1 parent aa4c834
commit bff277a
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Showing 5 changed files with 21 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,5 @@
+* Added support for matching some keys of an object against corresponding rules,
+	eg `%{ foo: FooRule }`
 * Added support for matching all keys of an object against corresponding rules,
 	eg `@{ foo: FooRule }`
 * Added support for using `_form` (`[]`) on an object input,

diff --git a/lib/ometajs/core.js b/lib/ometajs/core.js
@@ -688,12 +688,14 @@
 		_many1: function(x) {
 			return this._many(x, x.call(this));
 		},
-		_object: function(x) {
+		_object: function(x, matchAllInput) {
 			var v = this.anything();
 			this._pred(typeof v === 'object');
 			var ruleKeys = Object.keys(x),
 				result = {};
-			this._pred(ruleKeys.length === Object.keys(v).length);
+			if(matchAllInput) {
+				this._pred(ruleKeys.length === Object.keys(v).length);
+			}
 			for(var i = 0; i < ruleKeys.length; i++) {
 				var key = ruleKeys[i];
 				this._pred(v.hasOwnProperty(key));

diff --git a/src/bs-ometa-compiler.ometajs b/src/bs-ometa-compiler.ometajs
@@ -55,7 +55,8 @@ export ometa BSOMetaParser {
                  | ( keyword('undefined') | keyword('nil')
                    | keyword('true')      | keyword('false') ):x       -> [#App, #exactly, x]
                  | spaces (seqString | tokenString | string | number)
-                 | "@{" objectRules:x "}"                              -> [#Object,    x]
+                 | "@{" objectRules:x "}"                              -> [#Object,    x, true]
+                 | "%{" objectRules:x "}"                              -> [#Object,    x, false]
                  | "["  expr:x "]"                                     -> [#Form,      x]
                  | "<"  expr:x ">"                                     -> [#ConsBy,    x]
                  | "@<" expr:x ">"                                     -> [#IdxConsBy, x]
@@ -111,7 +112,7 @@ export ometa BSOMetaTranslator {
                  ]
                  -> [JSON.stringify(key), x].join(':')
                )+:o
-             ]                             -> ['this._object({', o.join(','), '})']                                .join(''),
+             ] (true|false):matchAllInput  -> ['this._object({', o.join(','), '},', matchAllInput, ')']                                .join(''),
   Form       transFn:x                     -> ['this._form(',          x, ')']                                     .join(''),
   ConsBy     transFn:x                     -> ['this._consumedBy(',    x, ')']                                     .join(''),
   IdxConsBy  transFn:x                     -> ['this._idxConsumedBy(', x, ')']                                     .join(''),

diff --git a/test/files/simple.ometajs b/test/files/simple.ometajs
@@ -26,4 +26,13 @@ export ometa Simple {
 			@{ 'simple': true }
 			-> 'should fail'
 		|	-> 'ok'
+	,
+	ObjectRulesMatchPartial1 =
+		%{ 'simple': true }
+		-> 'ok'
+	,
+	ObjectRulesMatchPartial2 =
+			%{ 'simple': true, 'simpler': true }
+			-> 'should fail'
+		|	-> 'ok'
 }
diff --git a/test/unit/api-test.js b/test/unit/api-test.js
@@ -23,7 +23,9 @@ var testMatches = {
 	FormObject: { 'simple': true },
 	ObjectRules: { 'simple': true },
 	ObjectRulesMatchAll1: { 'simple': true },
-	ObjectRulesMatchAll2: { 'simple': true, 'simpler': true }
+	ObjectRulesMatchAll2: { 'simple': true, 'simpler': true },
+	ObjectRulesMatchPartial1: { 'simple': true, 'simpler': true },
+	ObjectRulesMatchPartial2: { 'simple': true }
 };
 
 var runTests = function(test, grammar) {