Data update

Task/Factorial/Tcl/factorial-5.tcl

@@ -1,5 +1,6 @@
 proc ifact_caching n {
     global fact_cache
+        tailcall fact [expr {$n-1}] [expr {$n*$result}]
     if { ! [info exists fact_cache]} {
         set fact_cache {1 1}
     }

Task/Factorial/Tcl/factorial-6.tcl

@@ -1,11 +1,52 @@
-puts [ifact 30]
-puts [rfact 30]
-puts [ifact_caching 30]
+# calls cmd with args
+# retpeatedly in scope above
+proc trampoline {cmd args} {
 
-set n 400
-set iterations 10000
-puts "calculate $n factorial $iterations times"
-puts "ifact: [time {ifact $n} $iterations]"
-puts "rfact: [time {rfact $n} $iterations]"
-# for the caching proc, reset the cache between each iteration so as not to skew the results
-puts "ifact_caching: [time {ifact_caching $n; unset -nocomplain fact_cache} $iterations]"
+    # thunk is  {cmd {arg1 arg2 arg3 ...} }
+    set result [uplevel 1 [concat $cmd $args]]
+
+    # split into vars
+    lassign $result type thunk
+
+    # loop
+    while {$type eq "next"} {	
+        set result [uplevel 1 $thunk]
+	    lassign $result type thunk
+    }
+
+    set final_value  $thunk
+
+    return $final_value
+}
+
+# return  { value final_value    }
+#     or  { next {cmd arg1 arg2} }
+proc factorial_step {n result} {
+
+    if {$n <= 1} {
+	    set ret_value [list "value" $result]
+    } else {
+
+	    # n-1
+	    set next_n [expr {$n-1}]
+
+	    # (n-1) * fact(n)
+	    set next_result [expr {$n * $result}]
+	
+	    #  {func arg1 arg2}
+	    set next_thunk [list factorial_step $next_n $next_result]
+
+	    # Return the next step as a list
+	    set ret_value [list "next" $next_thunk]
+     }
+
+    return $ret_value
+}
+
+
+# The execution is wrapped by the trampoline
+proc factorial {n} {
+    return [trampoline factorial_step $n 1]
+}
+
+set f [factorial 100]

Task/Factorial/Tcl/factorial-7.tcl

@@ -1,5 +1,11 @@
-package require math::special
+puts [ifact 30]
+puts [rfact 30]
+puts [ifact_caching 30]
 
-proc gfact n {
-    expr {round([::math::special::Gamma [expr {$n+1}]])}
-}
+set n 400
+set iterations 10000
+puts "calculate $n factorial $iterations times"
+puts "ifact: [time {ifact $n} $iterations]"
+puts "rfact: [time {rfact $n} $iterations]"
+# for the caching proc, reset the cache between each iteration so as not to skew the results
+puts "ifact_caching: [time {ifact_caching $n; unset -nocomplain fact_cache} $iterations]"