4 ms·

> Stepping back a bit, YAML is good enough, and this problem has been incrementally bikeshedded since at least the 1970s, it is time to move on Nah, in the 197

> Stepping back a bit, YAML is good enough, and this problem has been incrementally bikeshedded since at least the 1970s, it is time to move on Nah, in the 1970s we had Lisp S-expressions that completely solved the problem, and everything since then has been regressions on S-expressions due to parenthesis phobia. After hearing that thing about the country code for Norway, I became convinced that YAML has to just die. Become an ex-markup language. Pine for the fjords. Be a syntax that wouldn't VOOM if you put 4 million volts through it. Join the choir invisible, etc. This is good: https://noyaml.com/ https://noyaml.com/ Erik Naggum had a notoriously NSFW rant about XML (over the top even for him) that I better not link to here, but lots of it applies to YAML as well.

fanf2 5y ago
S-expressions don’t completely solve the problem: they don’t have a syntax for maps, and in practice there are at least two common incompatible conventions: alist or plist?
- int_19h 5y ago
  I would argue that, in a data markup language, there shouldn't be a syntax for maps. Whether a given sequence should be treated as key-value pairs, and whether keys in that sequence are ordered or unordered, is something that is best defined by the schema, just like all other value types.
- kaliszad 5y ago
  EDN has maps, sets, vectors and lists and is extendable.
- dreamcompiler 5y ago
  Solutions for this problem that I've used in my own S-expression config files: 1. Use only alists for maps because they prevent off-by-one errors. 2. Allow plists because they're less verbose than alists and use reader macros to distinguish them, and allow the reader macro definitions to be in the same file. Most of the time I use option 1 because it's simpler.
- throwaway81523 5y ago
  Obviously the application has to interpret the Lisp object resulting from reading the S-expression, just like it has to interpret any JSON, YAML, or anything else that it reads. So for maps you can, as you mention, use alists or plists. Regarding other stuff mentioned: none of the encodings are supposed to be bijective (the writer emits the exact input that the reader ingested). Otherwise, for example, they couldn't have comments, unless those ended up in the data somehow. There is ASN.1 DER if you want that, but ASN.1 is generally disastrous. Stuff like escape chars were well specified in Lisps of the 1970s (at least the late 1970s), including in Scheme (1975). Floating point conversion is a different matter (it was even messier in the pre-IEEE 754 era than now) but I think the alternatives don't handle it well either. You probably have to use hexadecimal representation for binary floats. Maybe decimal floats will become more widely supported on future hardware. A type-checked approach can be seen in XMonad, whose config files use Haskell's Read typeclass for the equivalent of typed S-expressions.
lmm 5y ago
S-expressions don't solve the problem at all, you just get to fractally bikeshed all over again about what semantics they have and what transformations are or aren't equivalent. Does whitespace roundtrip through S-expressions? Who knows. Are numbers in S-expressions rounded to double precision on read/write? Umm, maybe. How do I escape a ) in one of my values? Hoo boy, pick any escape character you like and there's an implementation that does it.
- didibus 5y ago
  EDN solves all these problems: https://github.com/edn-format/edn https://github.com/edn-format/edn
mro_name 5y ago
I have to second that. Including the variant "canonical s-expressions" which is in fact a binary format.
otabdeveloper4 5y ago
Why of course, embedding a full-blown Lisp development environment for parsing a config file is totally sane and normal. (Sarcasm, just in case.)

fanf2 5y ago

S-expressions don’t completely solve the problem: they don’t have a syntax for maps, and in practice there are at least two common incompatible conventions: alist or plist?

int_19h 5y ago
I would argue that, in a data markup language, there shouldn't be a syntax for maps. Whether a given sequence should be treated as key-value pairs, and whether keys in that sequence are ordered or unordered, is something that is best defined by the schema, just like all other value types.
kaliszad 5y ago
EDN has maps, sets, vectors and lists and is extendable.
dreamcompiler 5y ago
Solutions for this problem that I've used in my own S-expression config files: 1. Use only alists for maps because they prevent off-by-one errors. 2. Allow plists because they're less verbose than alists and use reader macros to distinguish them, and allow the reader macro definitions to be in the same file. Most of the time I use option 1 because it's simpler.
throwaway81523 5y ago
Obviously the application has to interpret the Lisp object resulting from reading the S-expression, just like it has to interpret any JSON, YAML, or anything else that it reads. So for maps you can, as you mention, use alists or plists. Regarding other stuff mentioned: none of the encodings are supposed to be bijective (the writer emits the exact input that the reader ingested). Otherwise, for example, they couldn't have comments, unless those ended up in the data somehow. There is ASN.1 DER if you want that, but ASN.1 is generally disastrous. Stuff like escape chars were well specified in Lisps of the 1970s (at least the late 1970s), including in Scheme (1975). Floating point conversion is a different matter (it was even messier in the pre-IEEE 754 era than now) but I think the alternatives don't handle it well either. You probably have to use hexadecimal representation for binary floats. Maybe decimal floats will become more widely supported on future hardware. A type-checked approach can be seen in XMonad, whose config files use Haskell's Read typeclass for the equivalent of typed S-expressions.

lmm 5y ago

S-expressions don't solve the problem at all, you just get to fractally bikeshed all over again about what semantics they have and what transformations are or aren't equivalent. Does whitespace roundtrip through S-expressions? Who knows. Are numbers in S-expressions rounded to double precision on read/write? Umm, maybe. How do I escape a ) in one of my values? Hoo boy, pick any escape character you like and there's an implementation that does it.

didibus 5y ago
EDN solves all these problems: https://github.com/edn-format/edn https://github.com/edn-format/edn

mro_name 5y ago

I have to second that. Including the variant "canonical s-expressions" which is in fact a binary format.

otabdeveloper4 5y ago

Why of course, embedding a full-blown Lisp development environment for parsing a config file is totally sane and normal. (Sarcasm, just in case.)