Data commit

Task/Roman-numerals-Decode/BCPL/roman-numerals-decode.bcpl

@@ -0,0 +1,29 @@
+get "libhdr"
+
+let roman(s) = valof
+$(  let digit(ch) = valof
+    $(  let ds = table 'm','d','c','l','x','v','i'
+        let vs = table 1000,500,100,50,10,5,1
+        for i=0 to 6
+            if ds!i=(ch|32) then resultis vs!i
+        resultis 0
+    $)
+    let acc = 0
+    for i=1 to s%0
+    $(  let d = digit(s%i)
+        if d=0 then resultis 0
+        test i<s%0 & d<digit(s%(i+1))
+            do acc := acc-d
+            or acc := acc+d
+    $)
+    resultis acc
+$)
+
+let show(s) be writef("%S: %N*N", s, roman(s))
+
+let start() be
+$(  show("MCMXC")
+    show("MDCLXVI")
+    show("MMVII")
+    show("MMXXI")
+$)