Start making the standard-lib utf-8 aware

Finally implements _str.is_utf8, adds from_chars, from_char, to_chars,
char_at, char_len, (push|pop|shift|unshift)_char. Also, proper
character I/O for streams.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/test/run-pass/utf8_chars.rs b/src/test/run-pass/utf8_chars.rs
new file mode 100644
index 00000000..04f8f574
--- /dev/null
+++ b/src/test/run-pass/utf8_chars.rs
@@ -0,0 +1,32 @@
+use std;
+import std._str;
+import std._vec;
+import std.io;
+
+fn main() {
+  // Chars of 1, 2, 3, and 4 bytes
+  let vec[char] chs = vec('e', 'é', '€', 0x10000 as char);
+  let str s = _str.from_chars(chs);
+
+  check(_str.byte_len(s) == 10u);
+  check(_str.char_len(s) == 4u);
+  check(_vec.len[char](_str.to_chars(s)) == 4u);
+  check(_str.eq(_str.from_chars(_str.to_chars(s)), s));
+  check(_str.char_at(s, 0u) == 'e');
+  check(_str.char_at(s, 1u) == 'é');
+
+  check(_str.is_utf8(_str.bytes(s)));
+  check(!_str.is_utf8(vec(0x80_u8)));
+  check(!_str.is_utf8(vec(0xc0_u8)));
+  check(!_str.is_utf8(vec(0xc0_u8, 0x10_u8)));
+
+  auto stack = "a×c€";
+  check(_str.pop_char(stack) == '€');
+  check(_str.pop_char(stack) == 'c');
+  _str.push_char(stack, 'u');
+  check(_str.eq(stack, "a×u"));
+  check(_str.shift_char(stack) == 'a');
+  check(_str.shift_char(stack) == '×');
+  _str.unshift_char(stack, 'ß');
+  check(_str.eq(stack, "ßu"));
+}