refactor: use Pianola to evaluate the manifest

BREAKING CHANGE:

The API of the subroutines has changed:

Before: `(evaluator, subjectValue, values)`
Now: `(subjectValue, values, {evalutor})`

README.md

@@ -278,7 +278,7 @@ Example:
 ```js
 const x = surgeon({
   subroutines: {
-    mySubourtine: (evaluator, currentValue, [firstParameterValue, secondParameterValue]) => {
+    mySubourtine: (currentValue, [firstParameterValue, secondParameterValue]) => {
       console.log(currentValue, firstParameterValue, secondParameterValue);
 
       return parseInt(currentValue, 10) + 1;
@@ -381,11 +381,11 @@ x([
 
 ```
 
-In this example, Surgeon query executor (`x`) is invoked with two expressions (`foo bar baz` and `corge grault garply`). The first subroutine is executed with the subject value "qux". The second subroutine is invoked with a value that is the result of the first proceeding subroutine.
+In this example, Surgeon query executor (`x`) is invoked with two expressions (`foo bar baz` and `corge grault garply`). The first subroutine is executed with the subject value "qux". The second subroutine is executed with a value that is the result of the parent subroutine.
 
 The result of the query is the result of the last subroutine.
 
-Read [user-defined subroutines](https://github.com/gajus/surgeon#user-defined-subroutines) documentation for broader explanation of the role of the parameter values and the subject value.
+Read [user-defined subroutines](#user-defined-subroutines) documentation for broader explanation of the role of the parameter values and the subject value.
 
 ### The pipe operator (`|`)
 
@@ -459,7 +459,7 @@ x('select .title {0,} | read property textContent', subject);
 
 ### Name results
 
-Use an [`QueryChildrenType`](./src/types.js) object to give names to descending results.
+Use a [`QueryChildrenType`](./src/types.js) object to name the results of the descending expressions.
 
 ```js
 const subject = `
@@ -524,7 +524,7 @@ import surgeon, {
 
 const x = surgeon({
   subroutines: {
-    isRed: (evaluator, value) => {
+    isRed: (value) => {
       if (value === 'red') {
         return value;
       };
@@ -553,19 +553,19 @@ import surgeon, {
 
 const x = surgeon({
   subroutines: {
-    ra: (evaluator, subject, values) => {
-      return readSubroutine(evaluator, subject, ['attribute'].concat(values));
+    ra: (subject, values, bindle) => {
+      return readSubroutine(subject, ['attribute'].concat(values), bindle);
     },
-    rp: (evaluator, subject, values) => {
-      return readSubroutine(evaluator, subject, ['property'].concat(values));
+    rp: (subject, values, bindle) => {
+      return readSubroutine(subject, ['property'].concat(values), bindle);
     },
-    s: (evaluator, subject, values) => {
-      return selectSubroutine(evaluator, subject, [values.join(' '), '{1}']);
+    s: (subject, values, bindle) => {
+      return selectSubroutine(subject, [values.join(' '), '{1}'], bindle);
     },
-    sm: (evaluator, subject, values) => {
-      return selectSubroutine(evaluator, subject, [values.join(' '), '{0,}']);
+    sm: (subject, values, bindle) => {
+      return selectSubroutine(subject, [values.join(' '), '{0,}'], bindle);
     },
-    t: testSubroutine,
+    t: testSubroutine
   }
 });
 

package.json

@@ -11,15 +11,12 @@
     ]
   },
   "dependencies": {
-    "ajv": "^5.0.1-beta.2",
     "cheerio": "^0.22.0",
     "debug": "^2.6.0",
     "es6-error": "^4.0.1",
     "flow-runtime": "^0.2.1",
-    "nearley": "^2.7.11",
-    "regex-parser": "^2.2.5",
-    "scalpel": "^2.1.0",
-    "sprintf-js": "^1.0.3"
+    "pianola": "^1.0.1",
+    "regex-parser": "^2.2.5"
   },
   "description": "Declarative DOM extraction expression evaluator.",
   "devDependencies": {
@@ -39,7 +36,8 @@
     "husky": "^0.13.1",
     "nyc": "^10.1.2",
     "semantic-release": "^6.3.6",
-    "sinon": "^2.0.0-pre.5"
+    "sinon": "^2.0.0-pre.5",
+    "sprintf-js": "^1.0.3"
   },
   "engines": {
     "node": ">=5"
@@ -55,13 +53,12 @@
   "main": "./dist/index.js",
   "name": "surgeon",
   "nyc": {
+    "exclude": [
+      "src/evaluators/browserEvaluator.js"
+    ],
     "include": [
       "src/**/*.js"
     ],
-    "exclude": [
-      "src/evaluators/browserEvaluator.js",
-      "src/grammars/*.js"
-    ],
     "instrument": false,
     "reporter": [
       "text-lcov"
@@ -76,8 +73,7 @@
     "url": "https://github.com/gajus/surgeon"
   },
   "scripts": {
-    "build": "npm run compile-grammar && babel ./src --out-dir ./dist --copy-files --source-maps",
-    "compile-grammar": "nearleyc ./src/grammars/expressionGrammar.ne --out ./src/grammars/expressionGrammar.js",
+    "build": "babel ./src --out-dir ./dist --copy-files --source-maps",
     "lint": "eslint ./src ./test && flow",
     "precommit": "npm run lint && npm run test",
     "test": "ava --verbose"

src/factories/index.js

@@ -1,9 +1,7 @@
 // @flow
 
 import createConfiguration from './createConfiguration';
-import createQuery from './createQuery';
 
 export {
-  createConfiguration,
-  createQuery
+  createConfiguration
 };

src/index.js

@@ -1,8 +1,8 @@
 // @flow
 
+import pianola from 'pianola';
 import {
-  createConfiguration,
-  createQuery
+  createConfiguration
 } from './factories';
 import {
   InvalidDataError,
@@ -48,75 +48,32 @@ const builtInSubroutines = {
   test: testSubroutine
 };
 
-const queryDocument = (userSubroutines, evaluator, instructions, rootNode) => {
-  let result = rootNode;
-
-  let index = 0;
-
-  for (const instruction of instructions) {
-    if (instruction.subroutine === 'adopt') {
-      const children = {};
-
-      if (instruction.parameters.length !== 1) {
-        throw new SurgeonError('Unexpected parameter length.');
-      }
-
-      if (typeof instruction.parameters[0] !== 'object') {
-        throw new SurgeonError('test');
-      }
-
-      const childrenNames = Object.keys(instruction.parameters[0]);
-
-      for (const childName of childrenNames) {
-        children[childName] = queryDocument(userSubroutines, evaluator, instruction.parameters[0][childName], result);
-      }
-
-      return children;
-    }
-
-    const lastResult = result;
-
-    if (!userSubroutines[instruction.subroutine]) {
-      throw new SurgeonError('Subroutine does not exist.');
-    }
-
-    result = userSubroutines[instruction.subroutine](evaluator, result, instruction.parameters);
-
-    if (result instanceof InvalidValueSentinel) {
-      throw new InvalidDataError(lastResult, result);
-    }
-
-    index++;
-
-    if (Array.isArray(result)) {
-      const remainingInstructions = instructions.slice(index);
-
-      return result.map((newRootNode) => {
-        return queryDocument(userSubroutines, evaluator, remainingInstructions, newRootNode);
-      });
-    }
-  }
-
-  return result;
-};
-
 export default (userConfiguration?: UserConfigurationType) => {
   const configuration = createConfiguration(userConfiguration);
 
-  const userSubroutines = {
+  const subroutines = {
     ...configuration.subroutines,
     ...builtInSubroutines
   };
 
+  const handleResult = (resultValue, inputValue) => {
+    if (resultValue instanceof InvalidValueSentinel) {
+      throw new InvalidDataError(inputValue, resultValue);
+    }
+  };
+
+  const x = pianola({
+    bindle: {
+      evaluator: configuration.evaluator
+    },
+    handleResult,
+    subroutines
+  });
+
   // eslint-disable-next-line flowtype/no-weak-types
   return (instructions: DenormalizedQueryType, subject: string | Object) => {
-    const query = createQuery(instructions);
+    const startValue = typeof subject === 'string' ? configuration.evaluator.parseDocument(subject) : subject;
 
-    return queryDocument(
-      userSubroutines,
-      configuration.evaluator,
-      query,
-      typeof subject === 'string' ? configuration.evaluator.parseDocument(subject) : subject
-    );
+    return x(instructions, startValue);
   };
 };

src/parsers/index.js

@@ -1,9 +1,7 @@
 // @flow
 
-import parseExpression from './parseExpression';
 import parseQuantifierExpression from './parseQuantifierExpression';
 
 export {
-  parseExpression,
   parseQuantifierExpression
 };