Parser now uses context to store details of the computation

app/imports/parser/parseTree/AccessorNode.js

@@ -1,5 +1,4 @@
 import ParseNode from '/imports/parser/parseTree/ParseNode.js';
-import ErrorNode from '/imports/parser/parseTree/ErrorNode.js';
 import ConstantNode from '/imports/parser/parseTree/ConstantNode.js';
 
 export default class AccessorNode extends ParseNode {
@@ -22,19 +21,21 @@ export default class AccessorNode extends ParseNode {
       return new AccessorNode({
         name: this.name,
         path: this.path,
-        previousNodes: [this],
       });
     } else {
       throw new Meteor.Error(`Unexpected case: ${this.name} resolved to ${value}`);
     }
   }
-  reduce(scope){
+  reduce(scope, context){
     let result = this.compile(scope);
     if (result instanceof AccessorNode){
-      return new ErrorNode({
-        node: result,
-        error: `${this.toString()} could not be resolved`,
-        previousNodes: [result],
+      context.storeError({
+        type: 'info',
+        message: `${result.toString()} not found, set to 0`
+      });
+      return new ConstantNode({
+        type: 'number',
+        value: 0,
       });
     } else {
       return result;

app/imports/parser/parseTree/ArrayNode.js

@@ -5,9 +5,9 @@ export default class ArrayNode extends ParseNode {
     super(...arguments);
     this.values = values;
   }
-  compile(scope){
-    let values = this.values.map(node => node.compile(scope));
-    return new ArrayNode({values, previousNodes: [this]});
+  resolve(fn, scope, context){
+    let values = this.values.map(node => node[fn](scope, context));
+    return new ArrayNode({values});
   }
   toString(){
     return `[${this.values.map(node => node.toString()).join(', ')}]`;

app/imports/parser/parseTree/CallNode.js

@@ -8,21 +8,12 @@ export default class CallNode extends ParseNode {
     this.functionName = functionName;
     this.args = args;
   }
-  compile(scope){
-    return this.resolve('compile', scope);
-  }
-  roll(scope){
-    return this.resolve('roll', scope);
-  }
-  reduce(scope){
-    return this.resolve('reduce', scope);
-  }
-  resolve(fn, scope){
+  resolve(fn, scope, context){
     let func = functions[this.functionName];
     if (!func) return new ErrorNode({
       node: this,
       error: `${this.functionName} is not a function`,
-      previousNodes: [this],
+      context,
     });
     let args = castArgsToType({fn, scope, args: this.args, type: func.argumentType});
     if (args.failed){
@@ -30,25 +21,30 @@ export default class CallNode extends ParseNode {
         return new ErrorNode({
           node: this,
           error: 'Could not convert all arguments to the correct type',
-          previousNodes: [this],
+          context,
         });
       } else {
         return new CallNode({
           functionName: this.functionName,
           args: args,
-          previousNodes: [this],
         });
       }
     } else {
-      let value = func.fn.apply(null, args);
-      console.log({args})
-      return new ConstantNode({
-        value,
-        type: 'number',
-        previousNodes: [this],
-      });
+      try {
+        let value = func.fn.apply(null, args);
+        return new ConstantNode({
+          value,
+          type: 'number',
+          previousNodes: [this],
+        });
+      } catch (error) {
+        return new ErrorNode({
+          node: this,
+          error,
+          context,
+        });
+      }
     }
-
   }
   toString(){
     return `${this.functionName}(${this.args.map(node => node.toString()).join(', ')})`;

app/imports/parser/parseTree/ConstantNode.js

@@ -1,12 +1,11 @@
 import ParseNode from '/imports/parser/parseTree/ParseNode.js';
 
 export default class ConstantNode extends ParseNode {
-  constructor({value, type, rollTable}){
+  constructor({value, type}){
 		super(...arguments);
-    // string, number, boolean, numberArray, uncompiledNode
+    // string, number, boolean, uncompiledNode
     this.type = type;
     this.value = value;
-    if (rollTable) this.rollTable = rollTable;
   }
   compile(){
     return this;

app/imports/parser/parseTree/ErrorNode.js

@@ -1,10 +1,16 @@
 import ParseNode from '/imports/parser/parseTree/ParseNode.js';
 
 export default class ErrorNode extends ParseNode {
-  constructor({node, error}) {
+  constructor({node, error, context}) {
 		super(...arguments);
     this.node = node;
     this.error = error;
+    if (context){
+      context.storeError({
+        type: 'error',
+        message: error,
+      });
+    }
   }
   compile(){
     return this;

app/imports/parser/parseTree/IfNode.js

@@ -1,4 +1,5 @@
 import ParseNode from '/imports/parser/parseTree/ParseNode.js';
+import ConstantNode from '/imports/parser/parseTree/ConstantNode.js';
 
 export default class IfNode extends ParseNode {
   constructor({condition, consequent, alternative}){
@@ -11,25 +12,24 @@ export default class IfNode extends ParseNode {
     let {condition, consequent, alternative} = this;
     return `${condition.toString()} ? ${consequent.toString()} : ${alternative.toString()}`
   }
-  compile(scope){
-    return this.resolve('compile', scope);
-  }
-  roll(scope){
-    return this.resolve('roll', scope);
-  }
-  reduce(scope){
-    return this.resolve('reduce', scope);
-  }
   resolve(fn, scope){
     let condition = this.condition[fn](scope);
-    if (condition.value){
-      let consequent = this.consequent[fn](scope);
-      consequent.inheritDetails([condition, this]);
-      return this.consequent[fn](scope);
+    if (condition instanceof ConstantNode){
+      if (condition.value){
+        let consequent = this.consequent[fn](scope);
+        consequent.inheritDetails([condition, this]);
+        return this.consequent[fn](scope);
+      } else {
+        let alternative = this.alternative[fn](scope);
+        alternative.inheritDetails([condition, this]);
+        return alternative;
+      }
     } else {
-      let alternative = this.alternative[fn](scope);
-      alternative.inheritDetails([condition, this]);
-      return alternative;
+      return new IfNode({
+        condition: condition,
+        consequent: this.consequent,
+        alternative: this.alternative,
+      });
     }
   }
 }

app/imports/parser/parseTree/IndexNode.js

@@ -22,15 +22,6 @@ export default class IndexNode extends ParseNode {
       previousNodes: [this],
     });
   }
-  compile(scope){
-    return this.resolve('compile', scope);
-  }
-  roll(scope){
-    return this.resolve('roll', scope);
-  }
-  reduce(scope){
-    return this.resolve('reduce', scope);
-  }
   toString(){
     return `${this.array.toString()}[${this.index.toString()}]`;
   }

app/imports/parser/parseTree/OperatorNode.js

@@ -9,15 +9,6 @@ export default class OperatorNode extends ParseNode {
     this.fn = fn;
     this.operator = operator;
   }
-  compile(scope){
-    return this.resolve('compile', scope);
-  }
-  roll(scope){
-    return this.resolve('roll', scope);
-  }
-  reduce(scope){
-    return this.resolve('reduce', scope);
-  }
   resolve(fn, scope){
     let leftNode = this.left[fn](scope);
     let rightNode = this.right[fn](scope);

app/imports/parser/parseTree/ParenthesisNode.js

@@ -5,21 +5,15 @@ export default class ParenthesisNode extends ParseNode {
 		super(...arguments);
     this.content = content;
   }
-  compile(scope){
-    return this.resolve('compile', scope);
-  }
-  roll(scope){
-    return this.resolve('roll', scope);
-  }
-  reduce(scope){
-    return this.resolve('reduce', scope);
-  }
   resolve(fn, scope){
     let content = this.content[fn](scope);
-    if (content.constructor.name === 'ConstantNode'){
-      return content;
-    } else {
+    if (
+      content.constructor.name === 'IfNode' ||
+      content.constructor.name === 'OperatorNode'
+    ){
       return new ParenthesisNode({content, previousNodes: [this]});
+    } else {
+      return content;
     }
   }
   toString(){

app/imports/parser/parseTree/ParseNode.js

@@ -1,30 +1,29 @@
 export default class ParseNode {
-  constructor({previousNodes, detail}){
-    this.inheritDetails(previousNodes);
-    if (detail) this.pushDetails([detail]);
-  }
-  inheritDetails(nodes){
-    if (!nodes || !nodes.length) return;
-    nodes.forEach(node => this.pushDetails(node.details));
-  }
-  pushDetails(details){
-    if (!details || !details.length) return;
-    if (!this.details) this.details = [];
-    details.forEach(detail => this.details.push(detail));
-  }
-  compile(){
-    // Returns a ParseNode, a ConstantNode if possible
-    throw new Meteor.Error('Compile not implemented on ' + this.constructor.name);
-  }
   toString(){
     throw new Meteor.Error('toString not implemented on ' + this.constructor.name);
+  }
+  compile(scope, context){
+    // Returns a ParseNode, a ConstantNode if possible
+    if(this.resolve) {
+      return this.resolve('compile', scope, context);
+    } else {
+      throw new Meteor.Error('Compile not implemented on ' + this.constructor.name);
+    }
   }
 	// Compile, but turn rolls into arrays
-  roll(scope){
-    return this.compile(scope);
+  roll(scope, context){
+    if (this.resolve){
+      return this.resolve('roll', scope, context);
+    } else {
+      return this.compile(scope, context);
+    }
   }
 	// Compile, turn rolls into arrays, and reduce those arrays into single values
-	reduce(scope){
-		return this.roll(scope);
+	reduce(scope, context){
+    if (this.resolve){
+      return this.resolve('reduce', scope, context);
+    } else {
+      return this.roll(scope, context);
+    }
 	}
 }

app/imports/parser/parseTree/RollNode.js

@@ -22,7 +22,7 @@ export default class RollNode extends ParseNode {
       return `${this.left.toString()}d${this.right.toString()}`;
     }
   }
-  roll(scope){
+  roll(scope, context){
     let left = this.left.reduce(scope);
     let right = this.right.reduce(scope);
     if (!left.isInteger){
@@ -51,11 +51,10 @@ export default class RollNode extends ParseNode {
       let roll = ~~(randomSrc.fraction() * diceSize) + 1
       values.push(roll);
     }
-    return new RollArrayNode({
-      values,
-      detail: {number, diceSize, values},
-      previousNodes: [this, left, right],
-    });
+    if (context){
+      context.storeRoll({number, diceSize, values});
+    }
+    return new RollArrayNode({values});
   }
   reduce(scope){
     return this.roll(scope).reduce(scope);

app/imports/parser/parser.js

@@ -6,3 +6,31 @@ const nearleyGrammar = nearley.Grammar.fromCompiled(grammar);
 export default function parser(){
   return new nearley.Parser(nearleyGrammar);
 }
+
+export class CompilationContext {
+  constructor(){
+    this.errors = [];
+    this.rolls = [];
+  }
+  storeError(e){
+    this.errors.push(e);
+  }
+  storeRoll(r){
+    this.rolls.push(r);
+  }
+}
+
+export function parse(string){
+  let parser = new nearley.Parser(nearleyGrammar);
+  parser.feed(string);
+  let results = parser.results;
+  if (results.length === 1){
+    return results[0];
+  } else if (results.length === 0){
+    // Valid parsing up until now, but need more. Unexpected end of input.
+    return null;
+  } else {
+    console.warn('Grammar is ambiguous!', {string, results});
+    return results[0];
+  }
+}