Fix escape_double_quote

src/vtab/csvtab.rs

@@ -47,7 +47,7 @@ impl VTab<CSVTabCursor> for CSVTab {
         }
         let filename = try!(str::from_utf8(c_filename));
         let mut reader = try!(csv::Reader::from_file(filename)).has_headers(false); // TODO flexible ?
-        let mut cols = Vec::new();
+        let mut cols: Vec<String> = Vec::new();
 
         let args = &args[4..];
         for c_arg in args {
@@ -64,7 +64,7 @@ impl VTab<CSVTabCursor> for CSVTab {
                 } else if uc.contains("NO_QUOTE") {
                     reader = reader.quote(0);
                 } else {
-                    cols.push(escape_double_quote(String::from(arg)));
+                    cols.push(escape_double_quote(arg).into_owned());
                 }
             }
         }

src/vtab/int_array.rs

@@ -13,13 +13,13 @@ pub fn create_int_array(conn: &Connection, name: &str) -> Result<Rc<RefCell<Vec<
     let array = Rc::new(RefCell::new(Vec::new()));
     try!(conn.create_module(name, &INT_ARRAY_MODULE, Some(array.clone())));
     try!(conn.execute_batch(&format!("CREATE VIRTUAL TABLE temp.\"{0}\" USING \"{0}\"",
-                                     escape_double_quote(name.to_string()))));
+                                     escape_double_quote(name))));
     Ok(array)
 }
 
 pub fn drop_int_array(conn: &Connection, name: &str) -> Result<()> {
     conn.execute_batch(&format!("DROP TABLE temp.\"{0}\"",
-                                escape_double_quote(name.to_string())))
+                                escape_double_quote(name)))
 }
 
 init_module!(INT_ARRAY_MODULE, IntArrayVTab, IntArrayVTabCursor,

src/vtab/mod.rs

@@ -1,5 +1,7 @@
 //! Create virtual tables.
 //! (See http://sqlite.org/vtab.html)
+use std::borrow::Cow;
+use std::borrow::Cow::{Borrowed, Owned};
 use std::ffi::CString;
 use std::mem;
 use std::ptr;
@@ -128,12 +130,12 @@ pub fn declare_vtab(db: *mut ffi::sqlite3, sql: &str) -> Result<()> {
 }
 
 /// Escape double-quote (`"`) character occurences by doubling them (`""`).
-pub fn escape_double_quote(identifier: String) -> String {
+pub fn escape_double_quote<'a>(identifier: &'a str) -> Cow<'a, str> {
     if identifier.contains('"') {
         // escape quote by doubling them
-        identifier.replace("\"", "\"\"")
+        Owned(identifier.replace("\"", "\"\""))
     } else {
-        identifier
+        Borrowed(identifier)
     }
 }