Fix docs for simple_query

Also fixes the return type to be consistent with regular "Rows" API.

postgres/src/lib.rs

@@ -1365,9 +1365,11 @@ impl Connection {
     /// ```rust,no_run
     /// # use postgres::{Connection, TlsMode};
     /// # let conn = Connection::connect("", TlsMode::None).unwrap();
-    /// for row in &conn.simple_query("SELECT foo FROM bar WHERE baz = 'quux'").unwrap() {
-    ///     let foo: String = row.get("foo");
-    ///     println!("foo: {}", foo);
+    /// for response in &conn.simple_query("SELECT foo FROM bar WHERE baz = 'quux'").unwrap() {
+    ///     for row in response {
+    ///         let foo: &str = row.get("foo");
+    ///         println!("foo: {}", foo);
+    ///     }
     /// }
     /// ```
     pub fn simple_query(&self, query: &str) -> Result<Vec<TextRows>> {

postgres/src/text_rows.rs

@@ -9,6 +9,7 @@ use std::str;
 pub use postgres_shared::rows::RowIndex;
 
 use stmt::{Column};
+use {Result, error};
 
 /// The resulting rows of a query.
 pub struct TextRows {
@@ -145,25 +146,26 @@ impl<'a> TextRow<'a> {
     }
 
     /// stub
-    pub fn get<I>(&self, idx: I) -> Option<&str>
+    pub fn get<I>(&self, idx: I) -> &str
     where
         I: RowIndex + fmt::Debug,
     {
         match self.get_inner(&idx) {
-            Some(value) => value,
+            Some(Ok(value)) => value,
+            Some(Err(err)) => panic!("error retrieving column {:?}: {:?}", idx, err),
             None => panic!("no such column {:?}", idx),
         }
     }
 
     /// stub
-    pub fn get_opt<I>(&self, idx: I) -> Option<Option<&str>>
+    pub fn get_opt<I>(&self, idx: I) -> Option<Result<&str>>
     where
         I: RowIndex,
     {
         self.get_inner(&idx)
     }
 
-    fn get_inner<I>(&self, idx: &I) -> Option<Option<&str>>
+    fn get_inner<I>(&self, idx: &I) -> Option<Result<&str>>
     where
         I: RowIndex,
     {
@@ -173,6 +175,6 @@ impl<'a> TextRow<'a> {
         };
 
         self.data.get(idx)
-            .map(|s| str::from_utf8(s).ok())
+            .map(|s| str::from_utf8(s).map_err(|e| error::conversion(Box::new(e))))
     }
 }