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Bindings

docs/semantics/bindings.md

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Bindings

A "binding" is a portion of and Enso program that creates a new name and binds a value to that name.

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Binding Return Value

While some expression-based languages with bindings have the binding return the value assigned to the binding, we feel that this is far too error prone. Consider the following code as a demonstration:

ruby
if x = someExprEvaluatingToBool then foo else bar

This is the perennially-discussed C++ bug where you fail to type == in an if-statement.

Enso, instead, takes the approach where a binding expression returns the singleton value of the type Nothing, making the above-written code a type error.