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I know TCL has an interesting story about how the syntax is basically all embedded strings, or something. Does anyone know if it has a recursive structure, as i

I know TCL has an interesting story about how the syntax is basically all embedded strings, or something. Does anyone know if it has a recursive structure, as in lisp? Maybe it's more of an "everything is an X" structure, as in forth where everything is a "word".

catach 4y ago
I find this is a good explainer: https://wiki.tcl-lang.org/page/everything+is+a+string https://wiki.tcl-lang.org/page/everything+is+a+string
- tyingq 4y ago
  The page on the lack of "null" kind of goes with that as well: https://wiki.tcl-lang.org/page/null https://wiki.tcl-lang.org/page/null
tptacek 4y ago
Lots of people say Tcl is homoiconic. It can feel pretty lispy if you want to code that way, since evals and uplevels work a little like macros.
- RHSeeger 4y ago
  In my mind, Tcl _is_ a lisp. Admittedly, it's pretty far out on the family tree branches, but the overall structure feels very lispy to me.
onedognight 4y ago
The entire grammar is spelled out in the tcl(n) man page[0]. It’s amazingly concise and easy to learn from just this. To answer your question, it’s “as if” everything was a string, but the implementation is reasonably efficient and doesn’t convert all the time. [0] https://man.archlinux.org/man/Tcl.n.en https://man.archlinux.org/man/Tcl.n.en
deleted 4y ago
[deleted]
wernsey 4y ago
Yes, in Tcl everything is basically a string, but has Lisp-like recursive structures: An expression like `{foo {bar baz}}` evaluates to the string "foo {bar baz}" at first, but then that might be split into two strings "foo" and "bar baz" by the interpreter. I recall Tcl being described as a Lisp without the parenthesis many years ago, which I still think is somewhat apt. Antirez' article "Tcl the Misunderstood" [0] is well worth a read if you want to know more. He also has an interpreter, Picol [1], in 500 lines of C code that is very easy to read and to understand. [0] http://antirez.com/articoli/tclmisunderstood.html http://antirez.com/articoli/tclmisunderstood.html [1] http://oldblog.antirez.com/post/picol.html http://oldblog.antirez.com/post/picol.html

catach 4y ago

I find this is a good explainer: https://wiki.tcl-lang.org/page/everything+is+a+string https://wiki.tcl-lang.org/page/everything+is+a+string

tyingq 4y ago
The page on the lack of "null" kind of goes with that as well: https://wiki.tcl-lang.org/page/null https://wiki.tcl-lang.org/page/null

tptacek 4y ago

Lots of people say Tcl is homoiconic. It can feel pretty lispy if you want to code that way, since evals and uplevels work a little like macros.

RHSeeger 4y ago
In my mind, Tcl _is_ a lisp. Admittedly, it's pretty far out on the family tree branches, but the overall structure feels very lispy to me.

onedognight 4y ago

The entire grammar is spelled out in the tcl(n) man page[0]. It’s amazingly concise and easy to learn from just this. To answer your question, it’s “as if” everything was a string, but the implementation is reasonably efficient and doesn’t convert all the time. [0] https://man.archlinux.org/man/Tcl.n.en https://man.archlinux.org/man/Tcl.n.en

deleted 4y ago

[deleted]

wernsey 4y ago

Yes, in Tcl everything is basically a string, but has Lisp-like recursive structures: An expression like `{foo {bar baz}}` evaluates to the string "foo {bar baz}" at first, but then that might be split into two strings "foo" and "bar baz" by the interpreter. I recall Tcl being described as a Lisp without the parenthesis many years ago, which I still think is somewhat apt. Antirez' article "Tcl the Misunderstood" [0] is well worth a read if you want to know more. He also has an interpreter, Picol [1], in 500 lines of C code that is very easy to read and to understand. [0] http://antirez.com/articoli/tclmisunderstood.html http://antirez.com/articoli/tclmisunderstood.html [1] http://oldblog.antirez.com/post/picol.html http://oldblog.antirez.com/post/picol.html