Article describes try/finally as a hack to get the effect of defer, but it looks to me like it's the other way around? Try/finally is more traditional, in one form or another.
Reasonably? Yes. Could probably be made to work well.
$ bat 2.ts
───────────────
1 │ function one() {
2 │ let x = 1;
3 │ defer (() => { throw new Error("thrown from one!"); })()
4 │ x = 2;
5 │ }
6 │ one();
─────┴─────────
$ node 2.js
~/healeycodes-typescript-go/2.js:29
throw _errors_1[0];
^
Error: thrown from one!
at _callee_1 (/Users/andrew/Documents/GitHub/healeycodes-typescript-go/2.js:9:46)
at /Users/andrew/Documents/GitHub/healeycodes-typescript-go/2.js:10:33
at one (/Users/andrew/Documents/GitHub/healeycodes-typescript-go/2.js:22:31)
at Object.<anonymous> (/Users/andrew/Documents/GitHub/healeycodes-typescript-go/2.js:34:1)
at Module._compile (node:internal/modules/cjs/loader:1830:14)
at Object..js (node:internal/modules/cjs/loader:1961:10)
at Module.load (node:internal/modules/cjs/loader:1553:32)
at Module._load (node:internal/modules/cjs/loader:1355:12)
at wrapModuleLoad (node:internal/modules/cjs/loader:255:19)
at Module.executeUserEntryPoint [as runMain (node:internal/modules/run_main:154:5)
Node.js v24.15.0
Is "defer" a good pattern? Aren't constructors/destructor pairs, like in C++/Rust, or "with" blocks in Python, better, because you cannot forget to call the destructor. I the first code example in the article, it is easy to omit "defer" and the compiler won't notice.
8 comments
[ 0.18 ms ] story [ 5.9 ms ] threadIt's also more exception-safe when you have more than one throwing call in the try block.
defer is the thing I miss the most coming from Go