langs a-z

Task/Binary-strings/PL-I/binary-strings.pli

@@ -0,0 +1,22 @@
+/* PL/I has immediate facilities for all those operations except for */
+/* replace. */
+s = t;                     /* assignment */
+s = t || u;                /* catenation - append one or more bytes. */
+if length(s) = 0 then ...  /* test for an empty string.              */
+if s = t then ...          /* compare strings.                       */
+u = substr(t, i, j);       /* take a substring of t beginning at the */
+                           /* i-th character andcontinuing for j     */
+                           /* characters.                            */
+substr(u, i, j) = t;       /* replace j characters in u, beginning   */
+                           /* with the i-th character.               */
+
+/* In string t, replace every occurrence of string u with string v.  */
+replace: procedure (t, u, v);
+   declare (t, u, v) character (*) varying;
+
+   do until (k = 0);
+      k = index(t, u);
+      if k > 0 then
+         t = substr(t, 1, k-1) || v || substr(t, k+length(u));
+   end;
+end replace;