Initial data commit

Task/String-case/ALGOL-68/string-case.alg

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+#!/usr/local/bin/a68g --script #
+
+# Demonstrate toupper and tolower for standard ALGOL 68
+strings.  This does not work for multibyte character sets. #
+
+INT l2u = ABS "A" - ABS "a";
+
+PROC to upper = (CHAR c)CHAR:
+  (ABS "a" > ABS c | c |: ABS c > ABS "z" | c | REPR ( ABS c + l2u ));
+
+PROC to lower = (CHAR c)CHAR:
+  (ABS "A" > ABS c | c |: ABS c > ABS "Z" | c | REPR ( ABS c - l2u ));
+
+# Operators can be defined in ALGOL 68 #
+OP (CHAR)CHAR TOLOWER = to lower, TOUPPER = to upper;
+
+# upper-cases s in place #
+PROC string to upper = (REF STRING s)VOID:
+    FOR i FROM LWB s TO UPB s DO s[i] := to upper(s[i]) OD;
+
+# lower-cases s in place #
+PROC string to lower = (REF STRING s)VOID:
+    FOR i FROM LWB s TO UPB s DO s[i] := to lower(s[i]) OD;
+
+main: (
+    STRING t := "alphaBETA";
+    string to upper(t);
+    printf(($"uppercase: "gl$, t));
+    string to lower(t);
+    printf(($"lowercase: "gl$, t))
+)