Merge pull request #15 from lordnull/mw-add-min-max-possible

Mw add min max possible
lordnull · Feb 4, 2016 · 21124f7 · 21124f7
2 parents 307705e + f2ca65e
commit 21124f7
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Showing 5 changed files with 246 additions and 24 deletions.
diff --git a/README.md b/README.md
@@ -185,6 +185,27 @@ For more advanced usage, scopes can be nested.
     var result = dice.roll("[takes.priority] + [nested.value]", scope);
     result == 10; // because we look for an exact match of property name first
 
+Statistics
+==========
+
+If you want some analysis for your rolls, you can get a result set created with
+some basic stats tagged in.
+
+Using `dice.statistics(rollString, scope, samples)` returns an object:
+
+```javascript
+    {
+        'results': [dice_roll_result], // The result set generated
+        'mean': number,                // The average of result set generated
+        'min': number,                 // The smallest value in the result set
+        'max': number,                 // The largest value in the result set
+        'min_possible': number,        // The smallest value that could have
+                                       // been generated.
+        'max_possible': number,        // The largest value that could have
+                                       // been generated.
+    }
+```
+
 Contributing
 ============
 

diff --git a/build/dice.js b/build/dice.js
@@ -49,6 +49,7 @@ module.exports={
 var dice = {
 	parse: require('./parser').parse,
 	eval: require('./evaluate').eval,
+	ops: require('./evaluate').ops,
 	version: require('../package').version
 };
 
@@ -75,14 +76,93 @@ dice.statistics = function(str, scope, samples){
 	var mean = resultSet.reduce(function(n, acc){ return n + acc; }, 0) / samples;
 	var min = resultSet.reduce(function(n, acc){ return n < acc ? n : acc; }, resultSet[0]);
 	var max = resultSet.reduce(function(n, acc){ return n > acc ? n : acc; }, resultSet[0]);
+
+	var parsed = dice.parse(str);
+
+	var minMaxPossible = determine_min_max_possible(parsed, scope);
+
 	return {
 		'results': resultSet,
 		'mean': mean,
 		'min': parseInt(min.toFixed()),
-		'max': parseInt(max.toFixed())
+		'max': parseInt(max.toFixed()),
+		'min_possible': minMaxPossible[0],
+		'max_possible': minMaxPossible[1]
 	};
 };
 
+function determine_min_max_possible(opObject, scope){
+	if(opObject.op == 'static'){
+		return [opObject.value, opObject.value];
+	}
+	if(opObject.op == 'lookup'){
+		var lookup = dice.ops.lookup.call(opObject, scope);
+		return [lookup(scope), lookup(scope)];
+	}
+	if(opObject.op == 'floor'){
+		var minmax = determine_min_max_possible(opObject.args[0], scope);
+		return [Math.floor(minmax[0]), Math.floor(minmax[1])];
+	}
+	if(opObject.op == 'ceil'){
+		var minmax = determine_min_max_possible(opObject.args[0], scope);
+		return [Math.ceil(minmax[0]), Math.ceil(minmax[1])];
+	}
+	if(opObject.op == 'round'){
+		var minmax = determine_min_max_possible(opObject.args[0], scope);
+		return [Math.round(minmax[0]), Math.round(minmax[1])];
+	}
+	if(opObject.op == 'd'){
+		var multipleMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var randPartMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = randPartMinMax[0] * multipleMinMax[0];
+		var max = randPartMinMax[1] * multipleMinMax[1];
+		return [min, max];
+	}
+	if(opObject.op == 'w'){
+		var multipleMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var randPartMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = randPartMinMax[0] * multipleMinMax[0];
+		var max = randPartMinMax[1] * multipleMinMax[1];
+		return [min, max];
+	}
+	if(opObject.op == 'random'){
+		var minMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var maxMinMax = determine_min_max_possible(opObject.args[1], scope);
+		return [minMinMax[0], maxMinMax[1]];
+	}
+	if(opObject.op == '+'){
+		var leftMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var rightMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = leftMinMax[0] + rightMinMax[0];
+		var max = leftMinMax[1] + rightMinMax[1];
+		return [min, max];
+	}
+	if(opObject.op == '-'){
+		var leftMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var rightMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = leftMinMax[0] - rightMinMax[0];
+		var max = leftMinMax[1] - rightMinMax[1];
+		return [min, max];
+	}
+	if(opObject.op == '*'){
+		var leftMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var rightMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = leftMinMax[0] * rightMinMax[0];
+		var max = leftMinMax[1] * rightMinMax[1];
+		return [min, max];
+	}
+	if(opObject.op == '/'){
+		var leftMinMax = determine_min_max_possible(opObject.args[0], scope);
+		var rightMinMax = determine_min_max_possible(opObject.args[1], scope);
+		var min = leftMinMax[0] / rightMinMax[1];
+		var max = leftMinMax[1] / rightMinMax[0];
+		return [min, max];
+	}
+	if(opObject.op == 'paren_express'){
+		return determine_min_max_possible(opObject.args[0], scope);
+	}
+}
+
 function stringify_expression(evaled_op){
 	var sub = stringify(evaled_op.expression);
 	var prefix = evaled_op.op[0];