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".
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.
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.
