refactore: start applying visitors

Author: AndyOGo

src/createJsonLogic.js

@@ -1,5 +1,96 @@
+import isLogic from './isLogic';
+import getOperator from './getOperator';
+
 function createJsonLogic() {
+  const operations = {}
+  const visitors = {}
+
+  function addOperation(name, code) {
+    operations[name] = code;
+  }
+
+  function removeOperation(name) {
+    delete operations[name];
+  }
+
+  function addVisitor(name, code) {
+    if (Array.isArray(name)) {
+      name.forEach(addVisitor);
+    }
+
+    visitors[name] = code;
+  }
+
+  function removeVisitor(name) {
+    if (Array.isArray(name)) {
+      name.forEach(removeVisitor);
+    }
+
+    delete visitors[name];
+  }
+
+  function apply(logic, data) {
+    // Does this array contain logic? Only one way to find out.
+    if(Array.isArray(logic)) {
+      return logic.map(function(l) {
+        return apply(l, data);
+      });
+    }
+    // You've recursed to a primitive, stop!
+    if( ! isLogic(logic) ) {
+      return logic;
+    }
+
+    data = data || {};
+
+    const op = getOperator(logic);
+    let values = logic[op];
+    let i;
+
+    // easy syntax for unary operators, like {"var" : "x"} instead of strict {"var" : ["x"]}
+    if( ! Array.isArray(values)) {
+      values = [values];
+    }
+
+    // apply matching visitors first
+    if (typeof visitors[op] === 'function') {
+      return visitors[op](apply, data, values);
+    }
+
+    // Everyone else gets immediate depth-first recursion
+    values = values.map(function(val) {
+      return apply(val, data);
+    });
+
+    // The operation is called with "data" bound to its "this" and "values" passed as arguments.
+    // Structured commands like % or > can name formal arguments while flexible commands (like missing or merge) can operate on the pseudo-array arguments
+    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments
+    if(typeof operations[op] === "function") {
+      return operations[op].apply(data, values);
+    }else if(op.indexOf(".") > 0) { // Contains a dot, and not in the 0th position
+      var sub_ops = String(op).split(".");
+      var operation = operations;
+      for(i = 0; i < sub_ops.length; i++) {
+        // Descending into operations
+        operation = operation[sub_ops[i]];
+        if(operation === undefined) {
+          throw new Error("Unrecognized operation " + op +
+            " (failed at " + sub_ops.slice(0, i+1).join(".") + ")");
+        }
+      }
+
+      return operation.apply(data, values);
+    }
+
+    throw new Error("Unrecognized operation " + op );
+  }
 
+  return {
+    add_operation: addOperation,
+    rm_operation: removeOperation,
+    add_visitor: addVisitor,
+    rm_visitor: removeVisitor,
+  }
 }
 
 export default createJsonLogic;

src/helpers/apply.js

@@ -0,0 +1,19 @@
+import createJsonLogic from './createJsonLogic';
+import * as operations from './operations';
+import * as visitors from './visitors';
+
+const jsonLogic = createJsonLogic();
+
+Object.keys(operations).forEach(function(name) {
+  const operation = operations[name];
+
+  jsonLogic.add_operation(operation.code || name , operation);
+});
+
+Object.keys(visitors).forEach(function(name) {
+  const visitor = visitors[name];
+
+  jsonLogic.add_visitor(visitor.code || name , visitor);
+});
+
+export default jsonLogic;

src/index.js

@@ -1,6 +1,6 @@
 import truthy from "../helpers/truthy";
 
-function all(data, values) {
+function all(apply, data, values) {
   const scopedData = apply(values[0], data);
   const scopedLogic = values[1];
   // All of an empty set is false. Note, some and none have correct fallback after the for loop

src/visitors/all.js

@@ -1,6 +1,8 @@
 import truthy from "../helpers/truthy";
 
-function and(data, values, current) {
+function and(apply, data, values) {
+  let current;
+
   for(let i=0; i < values.length; i++) {
     current = apply(values[i], data);
     if( ! truthy(current)) {

src/visitors/and.js

@@ -1,6 +1,6 @@
 import truthy from '../helpers/truthy';
 
-function condition(data, values) {
+function condition(apply, data, values) {
   /* 'if' should be called with a odd number of parameters, 3 or greater
     This works on the pattern:
     if( 0 ){ 1 }else{ 2 };
@@ -27,6 +27,6 @@ function condition(data, values) {
   return null;
 }
 
-condition.code = 'if';
+condition.code = ['if', '?:'];
 
 export default condition;

src/visitors/condition.js

@@ -1,6 +1,6 @@
 import truthy from "../helpers/truthy";
 
-function filter(data, values) {
+function filter(apply, data, values) {
   const scopedData = apply(values[0], data);
   const scopedLogic = values[1];
 

src/visitors/filter.js

@@ -1,4 +1,4 @@
-function map(data, values) {
+function map(apply, data, values) {
   const scopedData = apply(values[0], data);
   const scopedLogic = values[1];
 

src/visitors/map.js

@@ -1,4 +1,4 @@
-function none(data, values) {
+function none(apply, data, values) {
   const filtered = apply({'filter' : values}, data);
 
   return filtered.length === 0;

src/visitors/none.js

@@ -1,6 +1,8 @@
 import truthy from "../helpers/truthy";
 
-function or(data, values, current) {
+function or(apply, data, values) {
+  let current;
+
   for(let i=0; i < values.length; i++) {
     current = apply(values[i], data);
     if( truthy(current) ) {