Dropped: Scala 2 Macros
The previous, experimental macro system has been dropped.
Instead, there is a cleaner, more restricted system based on two complementary concepts: inline and '{ ... }/${ ... } code generation. '{ ... } delays the compilation of the code and produces an object containing the code, dually ${ ... } evaluates an expression which produces code and inserts it in the surrounding ${ ... }. In this setting, a definition marked as inlined containing a ${ ... } is a macro, the code inside the ${ ... } is executed at compile-time and produces code in the form of '{ ... }. Additionally, the contents of code can be inspected and created with a more complex reflection API as an extension of '{ ... }/${ ... } framework.
inlinehas been implemented in Scala 3.- Quotes
'{ ... }and splices${ ... }has been implemented in Scala 3. - TASTy reflect provides more complex tree based APIs to inspect or create quoted code.