Merge pull request #39 from json-logic/proposal/val

`val` Proposal Implementation

Author: TotalTechGeek

asyncLogic.js

@@ -3,7 +3,7 @@
 
 import defaultMethods from './defaultMethods.js'
 import LogicEngine from './logic.js'
-import { isSync } from './constants.js'
+import { isSync, OriginalImpl } from './constants.js'
 import declareSync from './utilities/declareSync.js'
 import { buildAsync } from './compiler.js'
 import omitUndefined from './utilities/omitUndefined.js'
@@ -75,6 +75,13 @@ class AsyncLogicEngine {
     if (this.isData(logic, func)) return logic
     if (!this.methods[func]) throw new Error(`Method '${func}' was not found in the Logic Engine.`)
 
+    // A small but useful micro-optimization for some of the most common functions.
+    // Later on, I could define something to shut this off if var / val are redefined.
+    if ((func === 'var' || func === 'val') && this.methods[func][OriginalImpl]) {
+      const input = (!data || typeof data !== 'object') ? data : this.fallback.run(data, context, { above })
+      return this.methods[func].method(input, context, above, this)
+    }
+
     if (typeof this.methods[func] === 'function') {
       const input = (!data || typeof data !== 'object') ? [data] : await this.run(data, context, { above })
       const result = await this.methods[func](coerceArray(input), context, above, this)
@@ -210,5 +217,5 @@ class AsyncLogicEngine {
     return logic
   }
 }
-Object.assign(AsyncLogicEngine.prototype.truthy, { IDENTITY: true })
+Object.assign(AsyncLogicEngine.prototype.truthy, { [OriginalImpl]: true })
 export default AsyncLogicEngine

async_optimizer.js

@@ -28,7 +28,7 @@ function getMethod (logic, engine, methodName, above) {
   }
 
   let args = logic[methodName]
-  if (!args || typeof args !== 'object') args = [args]
+  if ((!args || typeof args !== 'object') && !method.optimizeUnary) args = [args]
 
   if (Array.isArray(args)) {
     const optimizedArgs = args.map(l => optimize(l, engine, above))
@@ -50,12 +50,12 @@ function getMethod (logic, engine, methodName, above) {
 
     if (isSync(optimizedArgs) && (method.method || method[Sync])) {
       const called = method.method ? method.method : method
-      return declareSync((data, abv) => called(coerceArray(typeof optimizedArgs === 'function' ? optimizedArgs(data, abv) : optimizedArgs, method.optimizeUnary), data, abv || above, engine), true)
+      if (method.optimizeUnary) return declareSync((data, abv) => called(typeof optimizedArgs === 'function' ? optimizedArgs(data, abv) : optimizedArgs, data, abv || above, engine.fallback), true)
+      return declareSync((data, abv) => called(coerceArray(typeof optimizedArgs === 'function' ? optimizedArgs(data, abv) : optimizedArgs), data, abv || above, engine), true)
     }
 
-    return async (data, abv) => {
-      return called(coerceArray(typeof optimizedArgs === 'function' ? await optimizedArgs(data, abv) : optimizedArgs, method.optimizeUnary), data, abv || above, engine)
-    }
+    if (method.optimizeUnary) return async (data, abv) => called(typeof optimizedArgs === 'function' ? await optimizedArgs(data, abv) : optimizedArgs, data, abv || above, engine)
+    return async (data, abv) => called(coerceArray(typeof optimizedArgs === 'function' ? await optimizedArgs(data, abv) : optimizedArgs), data, abv || above, engine)
   }
 }
 

compatibility.js

@@ -1,7 +1,9 @@
+import { Sync } from './constants.js'
 import defaultMethods from './defaultMethods.js'
 const oldAll = defaultMethods.all
 
 const all = {
+  [Sync]: oldAll[Sync],
   method: (args, context, above, engine) => {
     if (Array.isArray(args)) {
       const first = engine.run(args[0], context, above)

compiler.js

@@ -205,7 +205,7 @@ function buildString (method, buildState = {}) {
     }
 
     let coerce = engine.methods[func].optimizeUnary ? '' : 'coerceArray'
-    if (!coerce && Array.isArray(lower) && lower.length === 1) lower = lower[0]
+    if (!coerce && Array.isArray(lower) && lower.length === 1 && !Array.isArray(lower[0])) lower = lower[0]
     else if (coerce && Array.isArray(lower)) coerce = ''
 
     const argumentsDict = [', context', ', context, above', ', context, above, engine']

constants.js

@@ -3,7 +3,8 @@
 
 export const Sync = Symbol.for('json_logic_sync')
 export const Compiled = Symbol.for('json_logic_compiled')
-export const EfficientTop = Symbol.for('json_logic_efficientTop')
+export const OriginalImpl = Symbol.for('json_logic_original')
+export const Unfound = Symbol.for('json_logic_unfound')
 
 /**
  * Checks if an item is synchronous.
@@ -22,6 +23,6 @@ export function isSync (item) {
 
 export default {
   Sync,
-  EfficientTop,
+  OriginalImpl,
   isSync
 }