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					169 lines
				
				4.3 KiB
			
		
		
			
		
	
	
					169 lines
				
				4.3 KiB
			| 
											3 years ago
										 | export abstract class _CodeOrName { | ||
|  |   abstract readonly str: string | ||
|  |   abstract readonly names: UsedNames | ||
|  |   abstract toString(): string | ||
|  |   abstract emptyStr(): boolean | ||
|  | } | ||
|  | 
 | ||
|  | export const IDENTIFIER = /^[a-z$_][a-z$_0-9]*$/i | ||
|  | 
 | ||
|  | export class Name extends _CodeOrName { | ||
|  |   readonly str: string | ||
|  |   constructor(s: string) { | ||
|  |     super() | ||
|  |     if (!IDENTIFIER.test(s)) throw new Error("CodeGen: name must be a valid identifier") | ||
|  |     this.str = s | ||
|  |   } | ||
|  | 
 | ||
|  |   toString(): string { | ||
|  |     return this.str | ||
|  |   } | ||
|  | 
 | ||
|  |   emptyStr(): boolean { | ||
|  |     return false | ||
|  |   } | ||
|  | 
 | ||
|  |   get names(): UsedNames { | ||
|  |     return {[this.str]: 1} | ||
|  |   } | ||
|  | } | ||
|  | 
 | ||
|  | export class _Code extends _CodeOrName { | ||
|  |   readonly _items: readonly CodeItem[] | ||
|  |   private _str?: string | ||
|  |   private _names?: UsedNames | ||
|  | 
 | ||
|  |   constructor(code: string | readonly CodeItem[]) { | ||
|  |     super() | ||
|  |     this._items = typeof code === "string" ? [code] : code | ||
|  |   } | ||
|  | 
 | ||
|  |   toString(): string { | ||
|  |     return this.str | ||
|  |   } | ||
|  | 
 | ||
|  |   emptyStr(): boolean { | ||
|  |     if (this._items.length > 1) return false | ||
|  |     const item = this._items[0] | ||
|  |     return item === "" || item === '""' | ||
|  |   } | ||
|  | 
 | ||
|  |   get str(): string { | ||
|  |     return (this._str ??= this._items.reduce((s: string, c: CodeItem) => `${s}${c}`, "")) | ||
|  |   } | ||
|  | 
 | ||
|  |   get names(): UsedNames { | ||
|  |     return (this._names ??= this._items.reduce((names: UsedNames, c) => { | ||
|  |       if (c instanceof Name) names[c.str] = (names[c.str] || 0) + 1 | ||
|  |       return names | ||
|  |     }, {})) | ||
|  |   } | ||
|  | } | ||
|  | 
 | ||
|  | export type CodeItem = Name | string | number | boolean | null | ||
|  | 
 | ||
|  | export type UsedNames = Record<string, number | undefined> | ||
|  | 
 | ||
|  | export type Code = _Code | Name | ||
|  | 
 | ||
|  | export type SafeExpr = Code | number | boolean | null | ||
|  | 
 | ||
|  | export const nil = new _Code("") | ||
|  | 
 | ||
|  | type CodeArg = SafeExpr | string | undefined | ||
|  | 
 | ||
|  | export function _(strs: TemplateStringsArray, ...args: CodeArg[]): _Code { | ||
|  |   const code: CodeItem[] = [strs[0]] | ||
|  |   let i = 0 | ||
|  |   while (i < args.length) { | ||
|  |     addCodeArg(code, args[i]) | ||
|  |     code.push(strs[++i]) | ||
|  |   } | ||
|  |   return new _Code(code) | ||
|  | } | ||
|  | 
 | ||
|  | const plus = new _Code("+") | ||
|  | 
 | ||
|  | export function str(strs: TemplateStringsArray, ...args: (CodeArg | string[])[]): _Code { | ||
|  |   const expr: CodeItem[] = [safeStringify(strs[0])] | ||
|  |   let i = 0 | ||
|  |   while (i < args.length) { | ||
|  |     expr.push(plus) | ||
|  |     addCodeArg(expr, args[i]) | ||
|  |     expr.push(plus, safeStringify(strs[++i])) | ||
|  |   } | ||
|  |   optimize(expr) | ||
|  |   return new _Code(expr) | ||
|  | } | ||
|  | 
 | ||
|  | export function addCodeArg(code: CodeItem[], arg: CodeArg | string[]): void { | ||
|  |   if (arg instanceof _Code) code.push(...arg._items) | ||
|  |   else if (arg instanceof Name) code.push(arg) | ||
|  |   else code.push(interpolate(arg)) | ||
|  | } | ||
|  | 
 | ||
|  | function optimize(expr: CodeItem[]): void { | ||
|  |   let i = 1 | ||
|  |   while (i < expr.length - 1) { | ||
|  |     if (expr[i] === plus) { | ||
|  |       const res = mergeExprItems(expr[i - 1], expr[i + 1]) | ||
|  |       if (res !== undefined) { | ||
|  |         expr.splice(i - 1, 3, res) | ||
|  |         continue | ||
|  |       } | ||
|  |       expr[i++] = "+" | ||
|  |     } | ||
|  |     i++ | ||
|  |   } | ||
|  | } | ||
|  | 
 | ||
|  | function mergeExprItems(a: CodeItem, b: CodeItem): CodeItem | undefined { | ||
|  |   if (b === '""') return a | ||
|  |   if (a === '""') return b | ||
|  |   if (typeof a == "string") { | ||
|  |     if (b instanceof Name || a[a.length - 1] !== '"') return | ||
|  |     if (typeof b != "string") return `${a.slice(0, -1)}${b}"` | ||
|  |     if (b[0] === '"') return a.slice(0, -1) + b.slice(1) | ||
|  |     return | ||
|  |   } | ||
|  |   if (typeof b == "string" && b[0] === '"' && !(a instanceof Name)) return `"${a}${b.slice(1)}` | ||
|  |   return | ||
|  | } | ||
|  | 
 | ||
|  | export function strConcat(c1: Code, c2: Code): Code { | ||
|  |   return c2.emptyStr() ? c1 : c1.emptyStr() ? c2 : str`${c1}${c2}` | ||
|  | } | ||
|  | 
 | ||
|  | // TODO do not allow arrays here
 | ||
|  | function interpolate(x?: string | string[] | number | boolean | null): SafeExpr | string { | ||
|  |   return typeof x == "number" || typeof x == "boolean" || x === null | ||
|  |     ? x | ||
|  |     : safeStringify(Array.isArray(x) ? x.join(",") : x) | ||
|  | } | ||
|  | 
 | ||
|  | export function stringify(x: unknown): Code { | ||
|  |   return new _Code(safeStringify(x)) | ||
|  | } | ||
|  | 
 | ||
|  | export function safeStringify(x: unknown): string { | ||
|  |   return JSON.stringify(x) | ||
|  |     .replace(/\u2028/g, "\\u2028") | ||
|  |     .replace(/\u2029/g, "\\u2029") | ||
|  | } | ||
|  | 
 | ||
|  | export function getProperty(key: Code | string | number): Code { | ||
|  |   return typeof key == "string" && IDENTIFIER.test(key) ? new _Code(`.${key}`) : _`[${key}]` | ||
|  | } | ||
|  | 
 | ||
|  | //Does best effort to format the name properly
 | ||
|  | export function getEsmExportName(key: Code | string | number): Code { | ||
|  |   if (typeof key == "string" && IDENTIFIER.test(key)) { | ||
|  |     return new _Code(`${key}`) | ||
|  |   } | ||
|  |   throw new Error(`CodeGen: invalid export name: ${key}, use explicit $id name mapping`) | ||
|  | } | ||
|  | 
 | ||
|  | export function regexpCode(rx: RegExp): Code { | ||
|  |   return new _Code(rx.toString()) | ||
|  | } |