A derivate of [Lisp]. A programming language with even less syntax than Tcl itself. (but special forms and the like...? [RS])

----

[wdb] I strongly disagree that Scheme has less syntax than Tcl! Reason: the symbols have a value ''per se''. Tcl has no symbols as $varname is just a shortcut for [[set varname]] where ''varname'' is just a constant, and the procedure addressed by ''set'' carries all the semantics. In Tcl, the command ''list unknown'' returns ''unknown'' because it is a constant. In Scheme, ''(list unknown)'' throws an error unless a symbol ''unknown'' is defined. If you want to list an unknown symbol, indeed, you need the special form ''(quote unknown)'' resp. it's shortcut '' 'unknown ''. In Lisp, the special form ''quote'' is essential. In Tcl, it is not necessary as it can be defined as a regular procedure as follows:

 proc quote x {
    set x
 }

(Thank you [rs] for the hint with the combinator ''Identity''!)

----

See [Tcl and LISP] | [Playing LISP] | [Serial summing].

There's a [Tk]Scheme.  [[maybe more than one?]]

[wdb]: There is a Tk connection to the Scheme implementation Chicken [http://wolf-dieter-busch.de/html/Software/Tools/ChickenTk.htm]

The classic Scheme book is [SICP].





http://phaseit.net/claird/comp.lang.scheme/scheme.html
----
One interesting difference is that setting of (only global?) variables and function definition both are done with ''define'', which creates a lambda if its first element is a list. Just for experimenting, here's how to have that in Tcl:
 proc define {what how} {
     if {[llength $what]==1} {
          uplevel 1 set $what [list $how]
     } else {
          proc [lindex $what 0] [lrange $what 1 end] $how
     }
 }
 % define x 42
 42
 % define {+ x y} {expr {$x+$y}}
 % + $x $x
 84
This prevents us from having spaces in variable names (not a big problem), but presents the function name and arguments in one list, similar to how it will later be called - people sometimes wonder why we define ''proc foo {x y} {..}'' but call it ''foo $x $y''...
----
[Category Language]