Data commit

Task/String-case/BCPL/string-case.bcpl

@@ -0,0 +1,26 @@
+get "libhdr"
+
+// Check whether a character is an upper or lowercase letter
+let islower(x) = 'a' <= x <= 'z'
+let isupper(x) = 'A' <= x <= 'Z'
+
+// Convert a character to upper or lowercase
+let toupper(x) = islower(x) -> x - 32, x
+let tolower(x) = isupper(x) -> x + 32, x
+
+// Map a character function over a string
+let strmap(f,s) = valof
+$(  for i=1 to s%0 do s%i := f(s%i)
+    resultis s
+$)
+
+// Convert a string to upper or lowercase
+let strtoupper(s) = strmap(toupper,s)
+let strtolower(s) = strmap(tolower,s)
+
+let start() be
+$(  let s = "alphaBETA"
+    writef("   String: %S*N", s)
+    writef("Uppercase: %S*N", strtoupper(s))
+    writef("Lowercase: %S*N", strtolower(s))
+$)