To my surprise, mapcar is so fast (it's an elisp primitive) that creating lambdas is cheaper than using a loop:
miniblog.
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Of C-style langs, I think C++ has the steepest syntactic learning curve. Reading C is easy after Java, but lambdas and init lists are novel.
Contrasting C++ lambdas with Obj-C blocks: https://www.mikeash.com/pyblog/friday-qa-2011-06-03-objective-c-blocks-vs-c0x-lambdas-fight.html (generally similar, though naturally C++ gives you more rope/flexibility)
Emacs hook tip: try to just add functions to hooks, e.g. (add-hook 'prog-mode #'eldoc-mode). It's easier to remove functions than lambdas.