1 files changed, 93 insertions, 0 deletions
diff --git a/argparse/src/help.rs b/argparse/src/help.rs
new file mode 100644
index 0000000..c7145be
--- /dev/null
+++ b/argparse/src/help.rs
@@ -0,0 +1,93 @@
+use std::str::CharIndices;
+use std::io::Result as IoResult;
+use std::io::Write;
+
+use super::action::{IFlagAction, ParseResult};
+use super::action::ParseResult::Help;
+
+pub struct HelpAction;
+
+impl IFlagAction for HelpAction {
+    fn parse_flag(&self) -> ParseResult {
+        return Help;
+    }
+}
+
+
+struct WordsIter<'a> {
+    data: &'a str,
+    iter: CharIndices<'a>,
+}
+
+impl<'a> WordsIter<'a> {
+    fn new(data: &'a str) -> WordsIter<'a> {
+        return WordsIter {
+            data: data,
+            iter: data.char_indices(),
+            };
+    }
+}
+
+impl<'a> Iterator for WordsIter<'a> {
+    type Item = &'a str;
+    fn next(&mut self) -> Option<&'a str> {
+        let word_start;
+        loop {
+            let (idx, ch) = match self.iter.next() {
+                None => return None,
+                Some((idx, ch)) => ((idx, ch)),
+            };
+            match ch {
+                ' ' | '\t' | '\r' | '\n' => continue,
+                _ => {
+                    word_start = idx;
+                    break;
+                }
+            }
+        }
+        loop {
+            let (idx, ch) = match self.iter.next() {
+                None => break,
+                Some((idx, ch)) => ((idx, ch)),
+            };
+            match ch {
+                ' ' | '\t' | '\r' | '\n' => {
+                    return Some(&self.data[word_start..idx]);
+                }
+                _ => continue,
+            }
+        }
+        return Some(&self.data[word_start..self.data.len()]);
+    }
+}
+
+pub fn wrap_text(buf: &mut Write, data: &str, width: usize, indent: usize)
+    -> IoResult<()>
+{
+    let mut witer = WordsIter::new(data);
+    let mut off = indent;
+    match witer.next() {
+        None => {
+            return Ok(());
+        }
+        Some(word) => {
+            try!(buf.write(word.as_bytes()));
+            off += word.len();
+        }
+    }
+    for word in witer {
+        if off + word.len() + 1 > width {
+            try!(buf.write(b"\n"));
+            for _ in 0..indent {
+                try!(buf.write(b" "));
+            }
+            off = indent;
+        } else {
+            try!(buf.write(b" "));
+            off += 1;
+        }
+        try!(buf.write(word.as_bytes()));
+        off += word.len();
+    }
+    return Ok(());
+}