Add pattern matching on map objects

bryanjos · bryanjos · commit 7b49edb28bce · 2017-07-17T20:12:46.000-05:00
diff --git a/lib/tailored.js b/lib/tailored.js
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tailored",
-  "version": "2.5.0",
+  "version": "2.6.0",
   "description": "Pattern matching library",
   "main": "lib/tailored.js",
   "jsnext:main": "src/index.js",
@@ -16,15 +16,15 @@
   "author": "Bryan Joseph <bryanjos@gmail.com>",
   "license": "MIT",
   "devDependencies": {
-    "babel-core": "^6.24.0",
-    "babel-preset-env": "^1.3.2",
-    "babel-register": "^6.24.0",
-    "chai": "^3.5.0",
-    "mocha": "^3.2.0",
-    "rollup": "^0.41.0",
+    "babel-core": "^6.25.0",
+    "babel-preset-env": "^1.6.0",
+    "babel-register": "^6.24.1",
+    "chai": "^4.1.0",
+    "mocha": "^3.4.2",
+    "rollup": "^0.45.2",
     "rollup-plugin-babel": "^2.7.1"
   },
   "dependencies": {
-    "erlang-types": "^1.0.0"
+    "erlang-types": "^1.0.1"
   }
 }
diff --git a/src/tailored/checks.js b/src/tailored/checks.js
@@ -8,7 +8,7 @@ import {
   Type,
   StartsWith,
   Bound,
-  BitStringMatch,
+  BitStringMatch
 } from './types';
 
 function is_number(value) {
@@ -79,6 +79,10 @@ function is_function(value) {
   return Object.prototype.toString.call(value) == '[object Function]';
 }
 
+function is_map(value) {
+  return value instanceof Map;
+}
+
 export {
   is_number,
   is_string,
@@ -97,4 +101,5 @@ export {
   is_object,
   is_array,
   is_bitstring,
+  is_map
 };
diff --git a/src/tailored/match.js b/src/tailored/match.js
@@ -7,7 +7,7 @@ import {
   Type,
   StartsWith,
   Bound,
-  BitStringMatch,
+  BitStringMatch
 } from './types';
 
 const patternMap = new Map();
@@ -21,6 +21,7 @@ patternMap.set(Type.prototype, Resolvers.resolveType);
 patternMap.set(BitStringMatch.prototype, Resolvers.resolveBitString);
 patternMap.set(Number.prototype, Resolvers.resolveNumber);
 patternMap.set(Symbol.prototype, Resolvers.resolveSymbol);
+patternMap.set(Map.prototype, Resolvers.resolveMap);
 patternMap.set(Array.prototype, Resolvers.resolveArray);
 patternMap.set(String.prototype, Resolvers.resolveString);
 patternMap.set(Boolean.prototype, Resolvers.resolveBoolean);
diff --git a/src/tailored/resolvers.js b/src/tailored/resolvers.js
@@ -137,6 +137,30 @@ function resolveArray(pattern) {
   };
 }
 
+function resolveMap(pattern) {
+  let matches = new Map();
+
+  const keys = pattern.keys();
+
+  for (let key of keys) {
+    matches.set(key, buildMatch(pattern.get(key)));
+  }
+
+  return function(value, args) {
+    if (!Checks.is_map(value) || pattern.size > value.size) {
+      return false;
+    }
+
+    for (let key of keys) {
+      if (!value.has(key) || !matches.get(key)(value.get(key), args)) {
+        return false;
+      }
+    }
+
+    return true;
+  };
+}
+
 function resolveObject(pattern) {
   let matches = {};
 
@@ -342,5 +366,6 @@ export {
   resolveBoolean,
   resolveFunction,
   resolveNull,
-  resolveBitString
+  resolveBitString,
+  resolveMap
 };
diff --git a/test/defmatch.spec.js b/test/defmatch.spec.js
@@ -330,7 +330,24 @@ describe('defmatch', () => {
       };
 
       let fn = Tailored.defmatch(
-        Tailored.clause([Tailored.bound(bound_value)], val => true)
+        Tailored.clause([Tailored.capture(bound_value)], val => true)
+      );
+
+      expect(fn(value)).to.equal(true);
+    });
+
+    it('must match on maps with symbol keys', () => {
+      const bound_value = new Map([
+        [Symbol.for('__struct__'), Symbol.for('Elixir.Blueprint.AssertError')]
+      ]);
+
+      const value = new Map([
+        [Symbol.for('__struct__'), Symbol.for('Elixir.Blueprint.AssertError')],
+        [Symbol.for('msg'), 'something']
+      ]);
+
+      let fn = Tailored.defmatch(
+        Tailored.clause([Tailored.capture(bound_value)], val => true)
       );
 
       expect(fn(value)).to.equal(true);
diff --git a/yarn.lock b/yarn.lock
