Common Lisp reader macros hook into the reader itself as it's parsing S-exps and meets some character combination: http://www.ai.mit.edu/projects/iiip/doc/Commo

Common Lisp reader macros hook into the reader itself as it's parsing S-exps and meets some character combination: http://www.ai.mit.edu/projects/iiip/doc/CommonLISP/HyperSpec/Body/glo_r.html#reader_macro http://www.ai.mit.edu/projects/iiip/doc/CommonLISP/HyperSpec... Define-syntax is for making special forms (i.e. normal macros). Not that I know why eval should be paired with reader macros.