scripting: Add proof of concept (freezy/vpweb#1).

lib/scripting/.gitignore

@@ -0,0 +1,2 @@
+estree.js
+vbscript.js

lib/scripting/estree.ts

@@ -0,0 +1,51 @@
+/*
+ * VPDB - Virtual Pinball Database
+ * Copyright (C) 2019 freezy <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+import { Program, VariableDeclaration, VariableDeclarator } from 'estree';
+
+/**
+ * Returns the root node.
+ * @param data List of `GlobalStmt` nodes
+ */
+export function program(data: any): Program {
+	return {
+		type: 'Program',
+		sourceType: 'script',
+		body: data,
+	};
+}
+
+/**
+ * Returns a variable declaration.
+ * @param data Result of the `"Dim" __ VarName OtherVarsOpt:* NL` rule.
+ */
+export function varDecl(data: [string, null, string, string[]]): VariableDeclaration {
+	return {
+		type: 'VariableDeclaration',
+		kind: 'let',
+		declarations: [ data[2], ...data[3] ].map(variableDeclarator),
+	};
+}
+
+export function variableDeclarator(name: string): VariableDeclarator {
+	return {
+		type: 'VariableDeclarator',
+		id: { type: 'Identifier', name },
+	};
+}

lib/scripting/transpile.spec.ts

@@ -0,0 +1,31 @@
+/*
+ * VPDB - Virtual Pinball Database
+ * Copyright (C) 2019 freezy <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+import { expect } from 'chai';
+import { vbsToJs } from './transpile';
+
+describe('The VBScript transpiler', () => {
+
+	it('should transpile a variable declaration', () => {
+
+		const vbs = `Dim test1, test2, test3\n`;
+		const js = vbsToJs(vbs);
+		expect(js).to.equal('let test1, test2, test3;\n');
+	});
+});

lib/scripting/transpile.ts

@@ -0,0 +1,35 @@
+/*
+ * VPDB - Virtual Pinball Database
+ * Copyright (C) 2019 freezy <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+import { generate } from 'astring';
+import { Grammar, Parser } from 'nearley';
+
+const vbsGrammar = require('./vbscript.js');
+
+/**
+ * A function that transpiles VBScript to JavaScript.
+ */
+export function vbsToJs(vbs: string): string {
+	const parser = new Parser(Grammar.fromCompiled(vbsGrammar));
+	parser.feed(vbs);
+	if (parser.results.length === 0) {
+		throw new Error('Parser returned no results.');
+	}
+	return generate(parser.results[0]);
+}

lib/scripting/vbscript.ne

@@ -0,0 +1,68 @@
+@builtin "whitespace.ne"
+
+@{%
+const estree = require('./estree');
+%}
+
+Program              -> NLOpt GlobalStmt:*                           {% data => estree.program(data[1]) %}
+
+GlobalStmt           -> OptionExplicit
+                      | BlockStmt                                    {% data => data[0] %}
+
+
+OptionExplicit       -> "Option" __ "Explicit" NL
+
+BlockStmt            -> VarDecl                                      {% data => data[0] %}
+
+VarDecl              -> "Dim" __ VarName OtherVarsOpt:* NL           {% estree.varDecl %}
+
+VarName              -> ExtendedID ("(" ArrayRankList ")"):?         {% data => data[0] %}
+
+OtherVarsOpt         -> "," __ VarName                               {% data => data[2] %}
+
+ExtendedID           -> SafeKeywordID
+                      | ID                                           {% data => data[0] %}
+
+SafeKeywordID        -> "Default"
+                      | "Erase"
+                      | "Error"
+                      | "Explicit"
+                      | "Property"
+                      | "Step"
+
+ID                   -> Letter IDTail                                {% data => data[0] + data[1] %}
+                      | "[" IDNameChar:* "]"
+
+ArrayRankList        -> IntLiteral "," ArrayRankList
+                      | IntLiteral
+
+NLOpt                -> NL:*
+
+NL                   -> NewLine NL
+                      | NewLine
+
+NewLine              -> CR LF
+                      | CR
+                      | LF
+                      | ":"
+
+IntLiteral           -> DecDigit:+
+                      | HexLiteral
+                      | OctLiteral
+
+HexLiteral           -> "&H" HexDigit:+ "&":?
+OctLiteral           -> "&" OctDigit:+ "&":?
+
+DecDigit             -> [0-9]
+HexDigit             -> [0-9A-Fa-f]
+OctDigit             -> [0-7]
+
+IDNameChar           -> [\x20-\x5A\x5C\x5E-\x7E\xA0]
+
+Letter               -> [a-zA-Z]
+
+LF                   -> [\n]
+
+CR                   -> [\r]
+
+IDTail               -> [a-zA-Z0-9_]:*                               {% data => data[0].join('') %}

package.json

@@ -11,6 +11,7 @@
 	"scripts": {
 		"build": "rimraf dist && tsc && cp -r res/maps dist/res",
 		"build:watch": "tsc --watch",
+		"compile": "nearleyc lib/scripting/vbscript.ne -o lib/scripting/vbscript.js && tsc lib/scripting/estree",
 		"lint": "tslint lib/**/*.ts --format stylish",
 		"test": "nyc mocha"
 	},
@@ -35,19 +36,24 @@
 	"author": "freezy <[email protected]>",
 	"license": "GPL-2.0",
 	"dependencies": {
+		"astring": "^1.4.1",
 		"buffer": "5.4.0",
 		"es6-promise-pool": "^2.5.0",
 		"gltf-pipeline": "github:freezy/gltf-pipeline#hotfix/dedupe",
 		"gm": "^1.23.1",
+		"nearley": "^2.18.0",
 		"pngquant": "^3.0.0",
 		"sharp": "^0.23.0",
 		"three": "^0.107.0"
 	},
 	"devDependencies": {
+		"@types/astring": "^1.3.0",
 		"@types/chai": "4.2.0",
+		"@types/estree": "0.0.39",
 		"@types/gm": "1.18.4",
 		"@types/microtime": "2.1.0",
 		"@types/mocha": "5.2.7",
+		"@types/nearley": "2.11.0",
 		"@types/node": "12.7.2",
 		"@types/sharp": "0.22.2",
 		"@types/sinon": "7.0.13",