Merge pull request #1534 from killerswan/string_work

Added string functions: split_func, split_char, lines, lines_any, words

Author: brson

src/libcore/str.rs

@@ -7,7 +7,8 @@ String manipulation.
 export eq, lteq, hash, is_empty, is_not_empty, is_whitespace, byte_len,
        byte_len_range, index,
        rindex, find, starts_with, ends_with, substr, slice, split, splitn,
-       split_str, concat, connect, to_lower, to_upper, replace, char_slice,
+       split_str, split_func, split_char, lines, lines_any, words,
+       concat, connect, to_lower, to_upper, replace, char_slice,
        trim_left, trim_right, trim, unshift_char, shift_char, pop_char,
        push_char, is_utf8, from_chars, to_chars, char_len, char_len_range,
        char_at, bytes, is_ascii, shift_byte, pop_byte,
@@ -252,7 +253,7 @@ fn from_chars(chs: [char]) -> str {
 /*
 Function: utf8_char_width
 
-FIXME: What does this function do?
+Given a first byte, determine how many bytes are in this UTF-8 character
 */
 pure fn utf8_char_width(b: u8) -> uint {
     let byte: uint = b as uint;
@@ -275,15 +276,27 @@ Pluck a character out of a string and return the index of the next character.
 This function can be used to iterate over the unicode characters of a string.
 
 Example:
-
-> let s = "Clam chowder, hot sauce, pork rinds";
-> let i = 0;
-> while i < len(s) {
->   let {ch, next} = char_range_at(s, i);
->   log(debug, ch);
->   i = next;
+> let s = "中华Việt Nam";
+> let i = 0u;
+> while i < str::byte_len(s) {
+>    let {ch, next} = str::char_range_at(s, i);
+>    std::io::println(#fmt("%u: %c",i,ch));
+>    i = next;
 > }
 
+Example output:
+
+      0: 中
+      3: 华
+      6: V
+      7: i
+      8: ệ
+      11: t
+      12:
+      13: N
+      14: a
+      15: m
+
 Parameters:
 
 s - The string
@@ -721,6 +734,8 @@ Split a string at each occurance of a given separator
 Returns:
 
 A vector containing all the strings between each occurance of the separator
+
+FIXME: should be renamed to split_byte
 */
 fn split(s: str, sep: u8) -> [str] {
     let v: [str] = [];
@@ -772,6 +787,9 @@ leading fields are suppressed, and empty trailing fields are preserved.
 Returns:
 
 A vector containing all the strings between each occurrence of the separator.
+
+FIXME: should behave like split and split_char:
+         assert ["", "XXX", "YYY", ""] == split_str(".XXX.YYY.", ".");
 */
 fn split_str(s: str, sep: str) -> [str] {
     assert byte_len(sep) > 0u;
@@ -799,6 +817,76 @@ fn split_str(s: str, sep: str) -> [str] {
     ret v;
 }
 
+/*
+Function: split_func
+
+Splits a string into substrings using a function
+(unicode safe)
+
+FIXME: will be renamed to split.
+*/
+fn split_func(ss: str, sepfn: fn&(cc: char)->bool) -> [str] {
+    let vv: [str] = [];
+    let accum: str = "";
+    let ends_with_sep: bool = false;
+
+    str::iter_chars(ss, {|cc| if sepfn(cc) {
+            vv += [accum];
+            accum = "";
+            ends_with_sep = true;
+        } else {
+            str::push_char(accum, cc);
+            ends_with_sep = false;
+        }
+    });
+
+    if char_len(accum) >= 0u || ends_with_sep {
+        vv += [accum];
+    }
+
+    ret vv;
+}
+
+/*
+Function: split_char
+
+Splits a string into a vector of the substrings separated by a given character
+*/
+fn split_char(ss: str, cc: char) -> [str] {
+   split_func(ss, {|kk| kk == cc})
+}
+
+/*
+Function: lines
+
+Splits a string into a vector of the substrings
+separated by LF ('\n')
+*/
+fn lines(ss: str) -> [str] {
+    split_func(ss, {|cc| cc == '\n'})
+}
+
+/*
+Function: lines_any
+
+Splits a string into a vector of the substrings
+separated by LF ('\n') and/or CR LF ('\r\n')
+*/
+fn lines_any(ss: str) -> [str] {
+    vec::map(lines(ss), {|s| trim_right(s)})
+}
+
+/*
+Function: words
+
+Splits a string into a vector of the substrings
+separated by whitespace
+*/
+fn words(ss: str) -> [str] {
+    ret vec::filter( split_func(ss, {|cc| char::is_whitespace(cc)}),
+                     {|w| 0u < str::char_len(w)});
+}
+
 /*
 Function: concat
 

src/test/stdtest/str.rs

@@ -80,12 +80,83 @@ fn test_split_str() {
         let v = str::split_str(s, sep);
         assert str::eq(v[i], k);
     }
+
+    //FIXME: should behave like split and split_char:
+    //assert ["", "XXX", "YYY", ""] == str::split_str(".XXX.YYY.", ".");
+
     t("abc::hello::there", "::", 0, "abc");
     t("abc::hello::there", "::", 1, "hello");
     t("abc::hello::there", "::", 2, "there");
     t("::hello::there", "::", 0, "hello");
     t("hello::there::", "::", 2, "");
     t("::hello::there::", "::", 2, "");
+    t("ประเทศไทย中华Việt Nam", "中华", 0, "ประเทศไทย");
+    t("ประเทศไทย中华Việt Nam", "中华", 1, "Việt Nam");
+}
+
+#[test]
+fn test_split_func () {
+    let data = "ประเทศไทย中华Việt Nam";
+    assert ["ประเทศไทย中", "Việt Nam"]
+        == str::split_func (data, {|cc| cc == '华'});
+
+    assert ["", "", "XXX", "YYY", ""]
+         == str::split_func("zzXXXzYYYz", char::is_lowercase);
+
+    assert ["zz", "", "", "z", "", "", "z"]
+         == str::split_func("zzXXXzYYYz", char::is_uppercase);
+
+    assert ["",""] == str::split_func("z", {|cc| cc == 'z'});
+    assert [""] == str::split_func("", {|cc| cc == 'z'});
+    assert ["ok"] == str::split_func("ok", {|cc| cc == 'z'});
+}
+
+#[test]
+fn test_split_char () {
+    let data = "ประเทศไทย中华Việt Nam";
+    assert ["ประเทศไทย中", "Việt Nam"]
+        == str::split_char(data, '华');
+
+    assert ["", "", "XXX", "YYY", ""]
+         == str::split_char("zzXXXzYYYz", 'z');
+    assert ["",""] == str::split_char("z", 'z');
+    assert [""] == str::split_char("", 'z');
+    assert ["ok"] == str::split_char("ok", 'z');
+}
+
+#[test]
+fn test_lines () {
+    let lf = "\nMary had a little lamb\nLittle lamb\n";
+    let crlf = "\r\nMary had a little lamb\r\nLittle lamb\r\n";
+
+    assert ["", "Mary had a little lamb", "Little lamb", ""]
+      == str::lines(lf);
+
+    assert ["", "Mary had a little lamb", "Little lamb", ""]
+      == str::lines_any(lf);
+
+    assert ["\r", "Mary had a little lamb\r", "Little lamb\r", ""]
+      == str::lines(crlf);
+
+    assert ["", "Mary had a little lamb", "Little lamb", ""]
+      == str::lines_any(crlf);
+
+    assert [""] == str::lines    ("");
+    assert [""] == str::lines_any("");
+    assert ["",""] == str::lines    ("\n");
+    assert ["",""] == str::lines_any("\n");
+    assert ["banana"] == str::lines    ("banana");
+    assert ["banana"] == str::lines_any("banana");
+}
+
+#[test]
+fn test_words () {
+    let data = "\nMary had a little lamb\nLittle lamb\n";
+    assert ["Mary","had","a","little","lamb","Little","lamb"]
+        == str::words(data);
+
+    assert ["ok"] == str::words("ok");
+    assert [] == str::words("");
 }
 
 #[test]
@@ -215,6 +286,27 @@ fn test_char_slice() {
     assert (str::eq("bc", str::char_slice("abc", 1u, 3u)));
     assert (str::eq("", str::char_slice("abc", 1u, 1u)));
     assert (str::eq("\u65e5", str::char_slice("\u65e5\u672c", 0u, 1u)));
+
+    let data = "ประเทศไทย中华";
+    assert (str::eq("ป", str::char_slice(data, 0u, 1u)));
+    assert (str::eq("ร", str::char_slice(data, 1u, 2u)));
+    assert (str::eq("华", str::char_slice(data, 10u, 11u)));
+    assert (str::eq("", str::char_slice(data, 1u, 1u)));
+
+    fn a_million_letter_X() -> str {
+        let i = 0;
+        let rs = "";
+        while i < 100000 { rs += "华华华华华华华华华华"; i += 1; }
+        ret rs;
+    }
+    fn half_a_million_letter_X() -> str {
+        let i = 0;
+        let rs = "";
+        while i < 100000 { rs += "华华华华华"; i += 1; }
+        ret rs;
+    }
+    assert (str::eq(half_a_million_letter_X(),
+                    str::char_slice(a_million_letter_X(), 0u, 500000u)));
 }
 
 #[test]