Intercept Iterable string - backbone for template engines

import { iterableStringInterceptor } from "iterable-string-interceptor";
import { createReadStream } from "fs";
import { readFile } from "fs/promises";

// double values inside {{}}
// {{7}} -> 14
for await (const chunk of iterableStringInterceptor(createReadStream('aFile', { encoding: "utf8" }),
  expression => expression * 2
)) {
  process.stdout.write(chunk);
}

import { iterableStringInterceptor } from "iterable-string-interceptor";
import { createReadStream } from "fs";
import { readFile } from "fs/promises";

// handle expression as to be included content {{filename}}
for await (const chunk of iterableStringInterceptor(createReadStream('aFile', { encoding: "utf8" }),
  async * (expression) => { yield readFile(expression, { encoding: "utf8" }); }
)) {
  process.stdout.write(chunk);
}

• ExpressionTransformer
  • Parameters
• EarlyConsumerCallback
  • Parameters
• iterableStringInterceptor
  • Parameters

Type: function (string, string, Iterable<string>, EarlyConsumerCallback, string, string): AsyncIterable<string>

• expression string detected expression without leadIn / leadOut
• remainder string chunk after leadOut
• source Iterable<string> original source
• cb EarlyConsumerCallback to be called if remainder has changed
• leadIn string expression entry sequence
• leadOut string expression exit sequence

Returns AsyncIterable<string> transformed source

Will be called from the ExpressionTransformer if the given remainder needs to be altered.

Type: function (string): void

• remainder string new remainder to be used by iterableStringInterceptor

Intercept into a async iterable string source, detecting lead in/outs like '{{' and '}}' and asking a transformer for a replacement iterable string.

• source Iterable<string>
• transform ExpressionTransformer
• leadIn string expression entry sequence (optional, default "{{")
• leadOut string expression exit sequence (optional, default "}}")

Returns AsyncIterable<string> transformed source

With npm do:

npm install iterable-string-interceptor

BSD-2-Clause