You have a lot of very wrong opinions on Common Lisp.

> multiple values (cumbersome to use for superficial reasons

How so?

> Common Lisp has no eco system to speak off

False. https://www.quicklisp.org/beta/ https://cliki.net/

> the language is frozen/dead

False. Extensions are being done through libraries and in the implementations.

> career suicide, even compared to clojure

I only ever get positive attention for having been a professional Common Lisp (and Scheme) programmer. Never had trouble finding freelance or full-time work.

> no high quality free implementations (for example sbcl has a rather poor garbage collector compared to java, go and other widely used languages)

How do you go from "SBCL's GC is slower than Java's" (which is a nonsensical statement, because different JVMs have different GCs), to "no high-quality free implementations?" There are three Free Software ones to choose from: SBCL, CCL, and ECL.

> single precision is de-facto the default floating point type

False. Where do you even pick up a ridiculous idea like that? http://www.lispworks.com/documentation/HyperSpec/Body/t_shor...

> built around cons cells which are a terrible data structure

Ignoring how dumb labeling the linked list a "terrible data structure" is, you do realize that data structures are something that you implement in a language, not something that you have to build into one? There are libraries for all kinds of data structures.

> no out of the box support for laziness

There is no reason to make it built in at the language level when you have closures.

> no concurrency or parallelism abstractions

That is handled by implementations and libraries.

> no good standard pattern matching library

Just a bunch of really great ones.

> brain drain: very few smart people doing interesting things left (most left by the 90ies)

You don't seem to know anything or anyone from the Common Lisp world. The best techniques for using the language (advanced use of closures, read macros, the condition system, and applications to domain-specific languages and transpilation) have only started coming out in the past 15 years, from people like Edi Weitz, Doug Hoyte, and Tobias Rittweiler. The only thing relevant from the 1990s is Paul Graham's On Lisp. Norvig's PAIP is very overrated.

Wrt brain drain: Edi Weitz is a smart guy, but not in the same league as e.g. Henry Baker, Jeffrey Mark Siskind, David Moon, Bill Gosper, Guy Steele, Marvin Minsky, Peter Norvig etc. There are still several people worth following left, even if you're not a common lisp fanboi (e.g. paul khuong), but hardly a lot which are moving the state of computing forward to the extent it was the case for many decades.

Dough Hoyte wrote Let over Lambda which is strong on the same breathless prose gracing its blurp:

> Let Over Lambda is one of the most hardcore computer programming books out there. Starting with the fundamentals, it describes the most advanced features of the most advanced language:

but IMO much weaker than PAIP on the actual "hardcore" programming. I can see why it would appeal to you more.

Wrt single precision being the default floating point type in practice:

   * *read-default-float-format*
   SINGLE-FLOAT
   * (cos 355/113) 
   -1.0 
   * (cos (/ 355 113.0))
   -1.0
   * (cos (/ 355 113d0))  ; get a more accurate answer by using double float literal
   -0.9999999999999645d0

The only practical implementation which diverged from this for some time was CCL (which used doubles), and they gave up because of friction with the rest of the community. I don't have time to address all your other claims that what I wrote is ridiculously false right now, so if it makes you feel better you can tell yourself that you still showed me wrong on 9 out of 11 points.

> Wrt single precision being the default floating point type in practice:

The only relevant example in your list is the fact that irrational functions coerce rational arguments to single floats (http://clhs.lisp.se/Body/12_acc.htm). Why do you think that dividing an integer by a single float should produce a double float?

Well, at least I appear to have got half the point across so let me spell out the other half: unlike all mainstream languages (apart from Fortran, depending on your definition of mainstream) Common Lisp interprets "normal" floating point literals as single precision floats. Technically the standard does not specify this, but in practice all implementations do it this way these days. To be precise the standard says that SINGLE-FLOAT is the default, but implementing SINGLE-FLOAT as IEEE double precision float is allowable, because only a minimum precision and exponent size are suggested for each float type. CCL used to do this, using SHORT-FLOAT for IEEE single precision floats and, IIRC, both SINGLE-FLOAT and DOUBLE-FLOAT for double precision.

If you don't want this (and I almost never do), you either need to explicitly specify that you want double precision, using d as an exponent marker in your literals or ensure READ-DEFAULT-FLOAT-FORMAT is bound to DOUBLE-FLOAT (not it's default SINGLE-FLOAT) when you read them (which can go wrong more easily, so the former is typically better). The coercion problem is harder to work around.

So in the light of these facts what exactly is false and ridiculous about my claim that single precision floats are the default floating point type in practice in Common Lisp?

You don't understand what IEEE floating point numbers are.

IEEE 754 specifies a binary representation. There is no "normal" floating point literal notation. There are numbers in decimal or scientific notation, nothing about which will tell you what kind of internal representation the number should have (not even whether it should be floating point or not). You have to add syntax extensions (this is how Common Lisp does it: http://clhs.lisp.se/Body/02_cbb.htm) or pick an arbitrary representation. Is setting a variable to pick a representation more troublesome or "can go wrong more easily" that setting any other kind of variable for you, or is there something special about that particular variable? You might as well complain that the default Common Lisp reader/printer does not handle C99 hex float literals.

> You have to add syntax extensions (this is how Common Lisp does it: http://clhs.lisp.se/Body/02_cbb.htm) or pick an arbitrary representation.

If an unadorned numeric token such as 2.7 generates a single-precision float (32 bit IEEE 754), that is a problem. There are good justifications why the default representation should be the 64 bit double.

The 32 bit single precision has too small a range and precision for general use; it is suitable mainly for saving space in large arrays.

We shouldn't have to use an extra suffix to indicate that we don't want that type, but rather the common double.

Even C gets this right.

>>The best techniques for using the language

That is good, but availability of Libraries are better.

Let's face it. Most people can't use even basic programming features well. When programming went mainstream we traded art for plumbing. What matters now is being able to talk to http end points, working with databases, message buses and myriad of other backend interfaces.

To have widespread adoption you have to do library stuff well, and then may be other features will matter.

Perl is an interesting use case in this regards. The language is very 'functional programming language like' in nature but has a very practical focus for common people, while providing the powerful features for advanced users.