std: declared fns as pure where sensible

Author: boggle

src/libstd/bitv.rs

@@ -128,7 +128,7 @@ Function: get
 
 Retreive the value at index `i`
 */
-fn get(v: t, i: uint) -> bool {
+pure fn get(v: t, i: uint) -> bool {
     assert (i < v.nbits);
     let bits = uint_bits;
     let w = i / bits;

src/libstd/list.rs

@@ -112,7 +112,7 @@ Function: tail
 
 Returns all but the first element of a list
 */
-fn tail<copy T>(ls: list<T>) -> list<T> {
+pure fn tail<copy T>(ls: list<T>) -> list<T> {
     alt ls { cons(_, tl) { ret *tl; } nil. { fail "list empty" } }
 }
 
@@ -121,7 +121,7 @@ Function: head
 
 Returns the first element of a list
 */
-fn head<copy T>(ls: list<T>) -> T {
+pure fn head<copy T>(ls: list<T>) -> T {
     alt ls { cons(hd, _) { ret hd; } nil. { fail "list empty" } }
 }
 
@@ -130,7 +130,7 @@ Function: append
 
 Appends one list to another
 */
-fn append<copy T>(l: list<T>, m: list<T>) -> list<T> {
+pure fn append<copy T>(l: list<T>, m: list<T>) -> list<T> {
     alt l {
       nil. { ret m; }
       cons(x, xs) { let rest = append(*xs, m); ret cons(x, @rest); }

src/libstd/posix_fs.rs

@@ -30,6 +30,7 @@ fn list_dir(path: str) -> [str] {
 
 }
 
+// FIXME make pure when str::char_at is
 fn path_is_absolute(p: str) -> bool { ret str::char_at(p, 0u) == '/'; }
 
 const path_sep: char = '/';

src/libstd/rope.rs

@@ -310,7 +310,7 @@ Returns:
 
 A negative value if `left < right`, 0 if eq(left, right) or a positive
 value if `left > right`
- */
+*/
 fn cmp(left: rope, right: rope) -> int {
     alt((left, right)) {
       (node::empty., node::empty.) { ret 0; }

src/libstd/unicode.rs

@@ -151,16 +151,16 @@ mod icu {
     #[link_name = "icuuc"]
     #[abi = "cdecl"]
     native mod libicu {
-        fn u_hasBinaryProperty(c: UChar32, which: UProperty) -> UBool;
+        pure fn u_hasBinaryProperty(c: UChar32, which: UProperty) -> UBool;
     }
 }
 
-fn is_XID_start(c: char) -> bool {
+pure fn is_XID_start(c: char) -> bool {
     ret icu::libicu::u_hasBinaryProperty(c, icu::UCHAR_XID_START)
         == icu::TRUE;
 }
 
-fn is_XID_continue(c: char) -> bool {
+pure fn is_XID_continue(c: char) -> bool {
     ret icu::libicu::u_hasBinaryProperty(c, icu::UCHAR_XID_START)
         == icu::TRUE;
 }