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The scope is clearly defined by the parentheses, though if you're not used to Lisp syntax that can be confusing at first. (let n 12) => le

• zoren 3y ago
  In other lisps a let form has a body that the binding(s) range over and they are not available outside. As in `(let n 12 (+ n n))` here n wouldn't be accessible after. You have `(def name 5)` for making definitions that are readable outsude.
• trealira 3y ago
  In Lisp, "let" is only used for binding the variable, and it comes with a scope. (let ((a 1) (b 2)) (+ a b)) It's closer to the ML version of let, which works like this: let val a = 1 val b = 2 in a + b end You can sequence expressions for side effects, as well. (let ((a 1) (b 2)) (incf a) (do-it a b) (+ a b))
• nequo 3y ago
  Those lets in TFA seem more like Lisp’s setq rather than let. A let expression would bind values to names only within the scope of (let …) itself. The lets in TFA and in your examples have side effects. You reference the bound values outside of (let …).
• aidenn0 3y ago
  > The scope is clearly defined by the parentheses, though if you're not used to Lisp syntax that can be confusing at first. The scope is clearly not defined by the parentheses, and I've been programming in Common Lisp for 25 years, so I'm pretty used to Lisp syntax. A sibling comment suggests it comes from the JavaScript let (which did not exist when I learned JavaScript; it wasn't introduced until 1.7), which is scoped to the containing lexical block, rather than a block introduced by the let form itself.