3 ms·
It has eval but it lacks reader macros (or at least it did thirty years ago) which is what makes eval useful on lisp2 systems.
by bandrami 3mo ago
It has eval but it lacks reader macros (or at least it did thirty years ago) which is what makes eval useful on lisp2 systems.
- floxy 3mo agoI'm interested in reading more about how reader macros make `eval` better/useful.
- shakna 3mo agoR5RS supports reader macros? Which would be 1998, and I guess only 28 years ago. That's why SRFI-49 and its descendants were a possibility. Wisp, JavaScript, brainfuck, etc. implementations all exist because the tools exist in the language.
- jeandrek 3mo agoIt does not. https://conservatory.scheme.org/schemers/Documents/Standards/R5RS/HTML/r5rs-Z-H-5.html#%_chap_2 https://conservatory.scheme.org/schemers/Documents/Standards... Particular implementations could.
- shakna 3mo agoThat document, shows several forms: https://conservatory.scheme.org/schemers/Documents/Standards/R5RS/HTML/r5rs-Z-H-10.html#%_sec_7.3 https://conservatory.scheme.org/schemers/Documents/Standards...
- jeandrek 3mo agoCommon 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.
- deleted 3mo ago[deleted]