add logging function

README.md

@@ -3,3 +3,12 @@
 A collection of utility functions and classes extending base JavaScript.
 
 Intended for the Deno runtime.
+
+## Usage
+
+```ts
+import { log_from, range } from "https://git.barnulf.net/mb/barnulf_ts/raw/branch/master/mod.ts"
+const log = log_from(import.meta)
+
+for (const item of range(0, 10)) log(item)
+```

src/lib/utils.ts

@@ -21,3 +21,19 @@ export function next<T>(iterator: Iterator<T>) {
 export function* range(from: number, to: number) {
 	while (from < to) yield from++;
 }
+
+/**
+ * usage:
+ * ```ts
+ * const log = log_from(import.meta)
+ *
+ * const a = 4
+ * log("a", a)
+ * // [module.ts] a 4
+ * ```
+ */
+export function log_from(meta: ImportMeta, logging_function = console.log) {
+	const path = new URL(meta.url).pathname;
+	const prefix = `[${path}]`;
+	return (...args: unknown[]) => logging_function(prefix, ...args);
+}