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Escape hatches

To make eqWAlizer adoption practical, it features several mechanisms to make the type checker less strict, or to bypass it entirely.

Type dynamic()​

The built-in type dynamic() as well as eqwalizer:dynamic/1 (provided in app eqwalizer_support for the open source release) are a good way to make the type-checker more lenient while still providing some signal. See gradual typing.

Ignoring errors for a function completely​

Adding the directive -eqwalizer({nowarn_function, foo/1}) removes all warnings and errors issued by eqWAlizer when type-checking foo/1. Note that eqWAlizer will still type-check the function, but will not report errors. This allows eqWAlizer to emit a warning when this directive is redundant, that is, when foo/1 is well-typed.

Comments with eqwalizer:fixme and eqwalizer:ignore​

Adding a comment of the form % eqwalizer:fixme <reason> or % eqwalizer:ignore <reason> above a line containing an error suppresses this error. Idiomatically, eqwalizer:fixme should be used when a piece of code is temporarily ill-typed and should be fixed later, or if the error is due to an obvious gap in eqWAlizer. On the opposite, eqwalizer:ignore should be used when a piece of code deliberately and knowingly goes against types and specs. For example:

-spec foo() -> ok.
foo() ->
    % eqwalizer:ignore I know what I'm doing
    error.

As for the nowarn_function directive, eqWAlizer will emit a warning when such a comment is redundant and the line below is well-typed.