Merge pull request #13 from lordnull/mw-allow-nested-scopes

Allow Nested Scopes

README.md

@@ -171,6 +171,20 @@ Or if you need to roll half your level in d6's:
 
     c([Level] / 2)d6
 
+For more advanced usage, scopes can be nested.
+
+    var scope = {
+        'takes.priority': 3,
+        'takes':{
+            'priority': 5
+        },
+        'nested'{
+            'value': 7
+        }
+    };
+    var result = dice.roll("[takes.priority] + [nested.value]", scope);
+    result == 10; // because we look for an exact match of property name first
+
 Contributing
 ============
 

build/dice.js

@@ -153,7 +153,22 @@ var ops = {
 	'lookup': function(){
 		var variableName = this.value;
 		return function(scope){
-			return scope[variableName];
+			var undef;
+			var out = scope[variableName];
+			if(out != undef){
+				return out;
+			}
+			var split = variableName.split('.');
+			if(variableName == split){
+				return out;
+			}
+			reduceRes = split.reduce(function(acc, elem){
+				if(acc == undef){
+					return;
+				}
+				return acc[elem];
+			}, scope);
+			return reduceRes;
 		}
 	},
 
@@ -448,8 +463,8 @@ module.exports = (function() {
         peg$c52 = function(v) { return {'op':'lookup', 'value':v}; },
         peg$c53 = "[",
         peg$c54 = { type: "literal", value: "[", description: "\"[\"" },
-        peg$c55 = /^[a-zA-Z 0-9]/,
-        peg$c56 = { type: "class", value: "[a-zA-Z 0-9]", description: "[a-zA-Z 0-9]" },
+        peg$c55 = /^[^[\]]/,
+        peg$c56 = { type: "class", value: "[^[\\]]", description: "[^[\\]]" },
         peg$c57 = "]",
         peg$c58 = { type: "literal", value: "]", description: "\"]\"" },
         peg$c59 = function(varname) { return varname.join(""); },

src/dice.peg

@@ -71,7 +71,7 @@ lookup
   = v:variable { return {'op':'lookup', 'value':v}; }
 
 variable
-  = "[" varname:[a-zA-Z 0-9]+ "]" { return varname.join(""); }
+  = "[" varname:[^[\]]+ "]" { return varname.join(""); }
 
 integer "integer"
   = digits:[0-9]+ { return parseInt(digits.join(""), 10); }

src/evaluate.js

@@ -20,7 +20,22 @@ var ops = {
 	'lookup': function(){
 		var variableName = this.value;
 		return function(scope){
-			return scope[variableName];
+			var undef;
+			var out = scope[variableName];
+			if(out != undef){
+				return out;
+			}
+			var split = variableName.split('.');
+			if(variableName == split){
+				return out;
+			}
+			reduceRes = split.reduce(function(acc, elem){
+				if(acc == undef){
+					return;
+				}
+				return acc[elem];
+			}, scope);
+			return reduceRes;
 		}
 	},
 

tests/dice.spec.js

@@ -21,7 +21,8 @@ describe("Dice", function(){
 		"( 2d6 * 7)", "1d6 + (3d6 *7 )", "( 1 + 2) * 3",
 		"1d20 * (1d6 * ( 3 + [variable] ) )", "r([variable] + 2)d6",
 		"f(5 /3)", "( c([variable] / 7) + 3) * 2",
-		"3 + r(3/ [variable])"];
+		"3 + r(3/ [variable])", "1d[variable with space]",
+		"[variable.with.dot]d20", "3d6 + [varible with-mixed.odd_characters]"];
 
 		strings.map(function(toParse){
 			it("parses " + toParse, function(){
@@ -215,6 +216,35 @@ describe("Dice", function(){
 			expect(results.mean).toEqual(1);
 		});
 
+		it("can lookup weirdly named properties", function(){
+			var propName = "ಠ_ಠ and-more_unusual.characters#$!^*&";
+			var scope = {};
+			scope[propName] = 53;
+			var results = dice.roll("[" + propName + "]", scope);
+			expect(results).toEqual(53);
+		});
+
+		it("can lookup nested scope variables", function(){
+			var scope = {
+				upper: {
+					nested: 7
+				}
+			};
+			var results = dice.roll("[upper.nested]", scope);
+			expect(results).toEqual(7);
+		});
+
+		it("prefers full property name over nested scope", function(){
+			var scope = {
+				"upper.nested": 5,
+				upper: {
+					nested: 93
+				}
+			};
+			var results = dice.roll("[upper.nested]", scope);
+			expect(results).toEqual(5);
+		});
+
 	});
 });