Update

Backer/.eslintrc.js

@@ -4,8 +4,5 @@ module.exports = {
 		"browser": true,
 		"node": true,
 		"es6": true
-	},
-	"parserOptions": {
-		"project": "./tsconfig.json"
 	}
 }

Backer/package.json

@@ -15,8 +15,9 @@
 		"artistry-code-style": "0.0.2",
 		"eslint": "^6.1.0",
 		"eslint-plugin-filenames": "^1.3.2",
+		"liltest": "0.0.5",
+		"prettier-eslint": "^9.0.0",
 		"ts-node": "^8.3.0",
-		"typescript": "^3.5.3",
-		"prettier-eslint": "^9.0.0"
+		"typescript": "^3.5.3"
 	}
 }

Backer/src/X.ts

@@ -1,15 +1,18 @@
 import * as X from "../../Truth/Core/X";
 import { outdent } from "../../Truth/CoreTests/Framework/TestUtil";
-import { IR } from "./compiler/IR";
+import { IR } from "./compiler/Ir";
 import { JSEmitter } from "./compiler/JavaScriptEmitter";
+import { Writer } from "./writer/Writer";
+import * as fs from "fs";
+import { Placeholder } from "./writer/Placeholder";
 
 function main() 
 {
 	const source = outdent`
 	String
 	Number
 
-	Test User
+	User
 		Name: String
 		Age: Number
 
@@ -27,10 +30,33 @@ function main()
 
 	const prog = new X.Program();
 	const doc = prog.documents.create(source);
-
-	const result = IR.parseTruth(doc);
-	JSEmitter(result);
+
+	const path = __dirname + "/file.txt";
+	const fd = fs.openSync(path, "w+");
+
+	const writer = new Writer({
+		write(data, position) 
+		{
+			console.log(position, data);
+			fs.writeSync(fd, data, position, "utf-8");
+		},
+		truncate(length) 
+		{
+			fs.truncateSync(path, length);
+		}
+	});
+
+	const id1 = new Placeholder("World");
+	const id2 = new Placeholder("XXX");
+
+	writer.insert("Hllo ");
+	writer.insert("e", 1);
+	writer.insertIdentifier(id1);
+	writer.insert("!\n");
+
+	writer.insertIdentifier(id2);
+
+	id1.edit("Parsa");
 }
 
 main();
-setInterval(() => null, 1e4);

Backer/src/compiler/DiffService.ts

@@ -0,0 +1,97 @@
+import { IR } from "./Ir";
+import { Emitter } from "./Emitter";
+
+export class DiffService 
+{
+	constructor(
+		public readonly ir: IR.Document,
+		public readonly emitter: Emitter
+	) {}
+}
+
+export enum DiffKind {
+	ChildrenAdded,
+	ChildrenRemoved,
+	ChildrenRenamed,
+	InheritanceAdded,
+	InheritanceRemoved,
+	DeclarationAdded,
+	DeclarationRemoved
+}
+
+interface DiffBase {
+	readonly kind: DiffKind;
+}
+
+export type Diff =
+	| ChildrenAdded
+	| ChildrenRemoved
+	| ChildrenRenamed
+	| InheritanceAdded
+	| InheritanceRemoved
+	| DeclarationAdded
+	| DeclarationRemoved;
+
+export class ChildrenAdded implements DiffBase 
+{
+	public readonly kind = DiffKind.ChildrenAdded;
+
+	constructor(
+		public readonly base: IR.Declaration,
+		public readonly child: IR.Declaration
+	) {}
+}
+
+export class ChildrenRemoved implements DiffBase 
+{
+	public readonly kind = DiffKind.ChildrenRemoved;
+
+	constructor(
+		public readonly base: IR.Declaration,
+		public readonly child: IR.Declaration
+	) {}
+}
+
+export class ChildrenRenamed implements DiffBase 
+{
+	public readonly kind = DiffKind.ChildrenRenamed;
+
+	constructor(
+		public readonly base: IR.Declaration,
+		public readonly child: IR.Declaration
+	) {}
+}
+
+export class InheritanceAdded implements DiffBase 
+{
+	public readonly kind = DiffKind.InheritanceAdded;
+
+	constructor(
+		public readonly base: IR.Declaration,
+		public readonly name: string
+	) {}
+}
+
+export class InheritanceRemoved implements DiffBase 
+{
+	public readonly kind = DiffKind.InheritanceRemoved;
+
+	constructor(
+		public readonly base: IR.Declaration,
+		public readonly name: string
+	) {}
+}
+
+export class DeclarationAdded implements DiffBase 
+{
+	public readonly kind = DiffKind.DeclarationAdded;
+
+	constructor(public readonly declaration: IR.Declaration) {}
+}
+
+export class DeclarationRemoved implements DiffBase 
+{
+	public readonly kind = DiffKind.DeclarationRemoved;
+
+	constructor(public readonly declaration: IR.Declaration) {}
+}

Backer/src/compiler/Emitter.ts

@@ -0,0 +1,25 @@
+import { IR } from "./Ir";
+import { Writer } from "../writer/Writer";
+import * as D from "./DiffService";
+
+export abstract class Emitter 
+{
+	constructor(
+		public readonly ir: IR.Document,
+		public readonly writer: Writer
+	) {}
+
+	abstract [D.DiffKind.ChildrenAdded](diff: D.ChildrenAdded): void;
+
+	abstract [D.DiffKind.ChildrenRemoved](diff: D.ChildrenRemoved): void;
+
+	abstract [D.DiffKind.ChildrenRenamed](diff: D.ChildrenRenamed): void;
+
+	abstract [D.DiffKind.InheritanceAdded](diff: D.InheritanceAdded): void;
+
+	abstract [D.DiffKind.InheritanceRemoved](diff: D.InheritanceRemoved): void;
+
+	abstract [D.DiffKind.DeclarationAdded](diff: D.DeclarationAdded): void;
+
+	abstract [D.DiffKind.DeclarationRemoved](diff: D.DeclarationRemoved): void;
+}

Backer/src/compiler/IR.ts → Backer/src/compiler/Ir.ts

@@ -1,10 +1,10 @@
 import * as X from "../../../Truth/Core/X";
-import { camelize } from "./util";
+import { camelize } from "./Util";
 
 /**
  * This namespace contains all the functionalities and tools required to
  * deal with the Truth Intermediate representation.
- * 
+ *
  * @internal
  */
 export namespace IR {
@@ -26,6 +26,11 @@ export namespace IR {
 		parent?: Declaration;
 	};
 
+	export interface Representation {
+		statements: X.Statement[];
+		declarations: Document;
+	}
+
 	/**
 	 * Used in toIR to store deceleration stack entities.
 	 * @internal
@@ -40,11 +45,16 @@ export namespace IR {
 	 * @param doc A Truth document.
 	 * @returns The generated representation.
 	 */
-	export function parseTruth(doc: X.Document): Document {
+	export function parseTruth(doc: X.Document): Representation 
+	{
+		const statements: X.Statement[] = [];
 		const result = new Set<Declaration>();
 		let declarationStack: DeclarationInfo[] = [];
 
-		for (const statement of doc.eachStatement()) {
+		for (const statement of doc.eachStatement()) 
+		{
+			statements.push(statement);
+
 			if (statement.isWhitespace || statement.isComment || statement.isNoop)
 				continue;
 
@@ -67,14 +77,16 @@ export namespace IR {
 
 			const declarationStackEntity = { indent, declaration };
 
-			if (indent === 0) {
+			if (indent === 0) 
+			{
 				declarationStack = [declarationStackEntity];
 				result.add(declaration);
 				continue;
 			}
 
 			let lastDeclarationInfo: DeclarationInfo;
-			do {
+			do 
+			{
 				lastDeclarationInfo = declarationStack.pop()!;
 			} while (lastDeclarationInfo.indent >= indent);
 
@@ -89,6 +101,9 @@ export namespace IR {
 				parent.declarationName = parent.parent.declarationName + parent.name;
 		}
 
-		return [...result];
+		return {
+			statements,
+			declarations: [...result]
+		};
 	}
 }

Backer/src/compiler/JavaScriptEmitter.ts

@@ -1,35 +1,42 @@
-import { IR } from "./IR";
+import { IR } from "./Ir";
 import { outdent } from "../../../Truth/CoreTests/Framework/TestUtil";
 
-export function JSEmitter(declarations: IR.Document): void {
-  let result: string = `const TruthFactory = require("truth-factory");`;
+export function JSEmitter(declarations: IR.Document): void 
+{
+	let result: string = `const TruthFactory = require("truth-factory");`;
 
-  const isSpecial = (name: string): boolean => {
-    return name === "String" || name === "Number" || name === "Boolean";
-  }
+	const isSpecial = (name: string): boolean => 
+	{
+		return name === "String" || name === "Number" || name === "Boolean";
+	};
 
-  const quote = (name: string): string => isSpecial(name) ? name : `"${name}"`;
+	const quote = (name: string): string => isSpecial(name) ? name : `"${name}"`;
 
-  const type2str = (field: IR.Declaration): string => {
-    if (field.declarationName !== field.name) {
-      return quote(field.declarationName);
-    }
+	const type2str = (field: IR.Declaration): string => 
+	{
+		if (field.declarationName !== field.name) 
+		{
+			return quote(field.declarationName);
+		}
 
-    if (field.inheritedFrom.length === 0) {
-      return "TruthFactor.any";
-    }
+		if (field.inheritedFrom.length === 0) 
+		{
+			return "TruthFactor.any";
+		}
 
-    if (field.inheritedFrom.length === 1) {
-      return quote(field.inheritedFrom[0]);
-    }
+		if (field.inheritedFrom.length === 1) 
+		{
+			return quote(field.inheritedFrom[0]);
+		}
 
-    return `TruthFactory.union(${field.inheritedFrom.map(quote).join()})`;
-  };
+		return `TruthFactory.union(${field.inheritedFrom.map(quote).join()})`;
+	};
 
-  for (const declaration of declarations) {
-    if (isSpecial(declaration.name)) continue;
+	for (const declaration of declarations) 
+	{
+		if (isSpecial(declaration.name)) continue;
 
-    const code = outdent`
+		const code = outdent`
     const ${declaration.declarationName} = TruthFactory(
       "${declaration.declarationName}",
       [${declaration.inheritedFrom.map(name => `"${name}"`).join()}],
@@ -39,10 +46,10 @@ export function JSEmitter(declarations: IR.Document): void {
     );
     `;
 
-    result += "\n" + code;
-  }
+		result += "\n" + code;
+	}
 
-  result += `\nTruthFactory.resolve();`
+	result += `\nTruthFactory.resolve();`;
 
-  console.log(result);
-}
+	console.log(result);
+}

Backer/src/compiler/util.ts → Backer/src/compiler/Util.ts

@@ -3,7 +3,8 @@
  * @param  {string} str The input string.
  * @returns string The input in upperCameCase
  */
-export function camelize(str: string): string {
+export function camelize(str: string): string 
+{
 	return str
 		.replace(/(?:^\w|[A-Z]|\b\w)/g, word => word.toUpperCase())
 		.replace(/\s+/g, "");
@@ -14,7 +15,8 @@ export function camelize(str: string): string {
  * @param  {string} str The input string.
  * @returns string The input in lowerCamelCase.
  */
-export function lowerCamelize(str: string): string {
+export function lowerCamelize(str: string): string 
+{
 	return str
 		.replace(/(?:^\w|[A-Z]|\b\w)/g, (word, index) =>
 			index === 0 ? word.toLowerCase() : word.toUpperCase()

Backer/src/file.txt

@@ -0,0 +1,2 @@
+Hello Parsa!
+XXX