Earlier quoted context omitted.
how do you write it in other languages? sin(cos(10.4)); or v = 10.4; c = cos(v); s = sin(c); in Lisp one might write: (let* ((v 10.4) (c (cos v))) (sin c)) really old style: (prog (v c s) (setq v 10.4) (setq c (cos v)) (setq s (sin c)) s)
Thanks for the reply! I'd go the first route unless method chaining was available. SomeData.ToString().Trim() I would like to write idiomatic Lisp code and it's getting easier to read the nested expressions but it breaks the flow to leave the expression and wrap it. Another user mentioned using a command with Emacs to escape the expression and auto wrap it. That might be what I'm looking for.
This is the TXR Lisp interactive listener of TXR 215.
Quit with :quit or Ctrl-D on empty line. Ctrl-X ? for
cheatsheet.
1> [chain tostring trim-str]
#
2> [*1 3.4]
"3.4"
3> [[chain tostring trim-str] 3.4]
"3.4"
4> (defstruct foo nil
(:method print (me stream pretty-p)
(put-string "foo " stream)))
#
5> (tostring (new foo))
"foo "
6> [[chain tostring trim-str] (new foo)]
"foo"
1> (defstruct accum nil
(val 0)
(:method inc (me : (delta 1))
(inc me.val delta)
me)
(:method mul (me : (factor 2))
(upd me.val (* factor))
me))
#
2> (new accum).(inc).(inc).(mul 3)
#S(accum val 6)
3> (new accum).(inc).(inc).(mul 3).val
6
TXR's dot syntax is a very straightforward sugar for Lisp structure. Basically x.y.z == (qref x y z). Whitespace is not allowed around the dot. Numbers are also not allowed: 3.4 is a floating-point constant and a.3 or 3.a are invalid. If the leading element is missing, then it's the uref (unbound ref) operator: .y.z == (uref y z). This compiles to a function resembling (lambda (obj) obj.y.z).