Improve error handling.

src/vtab/csvtab.rs

@@ -6,6 +6,7 @@ use libc;
 
 use {Connection, Error, Result};
 use ffi;
+use types::Null;
 use vtab::declare_vtab;
 
 use self::csv::Reader;
@@ -27,19 +28,25 @@ struct CSVTab {
     base: ffi::sqlite3_vtab,
     reader: csv::Reader<File>,
     offset_first_row: u64,
+    cols: Vec<String>,
 }
 
 impl CSVTab {
     fn create(db: *mut ffi::sqlite3,
               aux: *mut libc::c_void,
-              _argc: libc::c_int,
+              argc: libc::c_int,
               _argv: *const *const libc::c_char)
               -> Result<CSVTab> {
+        if argc < 4 {
+            return Err(Error::ModuleError(format!("no CSV file specified")));
+        }
+        //let filename = ;
         let reader = try!(csv::Reader::from_file("FIXME"));
         let vtab = CSVTab {
             base: Default::default(),
             reader: reader,
             offset_first_row: 0,
+            cols: vec![], // FIXME
         };
         unimplemented!();
         try!(declare_vtab(db, "CREATE TABLE x FIXME"));
@@ -77,7 +84,7 @@ impl CSVTabCursor {
     fn filter(&mut self) -> Result<()> {
         {
             let vtab = self.vtab();
-            vtab.reader.seek(vtab.offset_first_row); // FIXME Result ignore
+            try!(vtab.reader.seek(vtab.offset_first_row));
         }
         self.row_number = 0;
         self.next()
@@ -85,7 +92,7 @@ impl CSVTabCursor {
     fn next(&mut self) -> Result<()> {
         let vtab = self.vtab();
         if vtab.reader.done() {
-            return Err(Error::SqliteFailure(ffi::Error::new(ffi::SQLITE_ERROR), None));
+            return Err(Error::ModuleError(format!("eof")));
         }
         unimplemented!();
         // self.row_number = self.row_number + 1;
@@ -95,10 +102,18 @@ impl CSVTabCursor {
         let vtab = self.vtab();
         unsafe { (*vtab).reader.done() }
     }
-    fn column(&self, ctx: *mut ffi::sqlite3_context, _i: libc::c_int) -> Result<()> {
+    fn column(&self, ctx: *mut ffi::sqlite3_context, col: libc::c_int) -> Result<()> {
+        use functions::ToResult;
         let vtab = self.vtab();
-        unimplemented!();
-        // TODO.set_result(ctx);
+        if col < 0 || col as usize >= vtab.cols.len() {
+            return Err(Error::ModuleError(format!("column index out of bounds: {}", col)));
+        }
+        if vtab.cols.is_empty() {
+            unsafe { Null.set_result(ctx) };
+            return Ok(());
+        }
+        // TODO Affinity
+        unsafe { vtab.cols[col as usize].set_result(ctx) };
         Ok(())
     }
     fn rowid(&self) -> Result<i64> {

src/vtab/mod.rs

@@ -172,6 +172,7 @@ unsafe extern "C" fn $destroy(vtab: *mut ffi::sqlite3_vtab) -> libc::c_int {
 unsafe extern "C" fn $open(vtab: *mut ffi::sqlite3_vtab,
                             pp_cursor: *mut *mut ffi::sqlite3_vtab_cursor)
                             -> libc::c_int {
+    use std::error::Error as StdError;
     use vtab::set_err_msg;
     let vt = vtab as *mut $vtab;
     match (*vt).open() {
@@ -186,7 +187,8 @@ unsafe extern "C" fn $open(vtab: *mut ffi::sqlite3_vtab,
             }
             err.extended_code
         }
-        Err(_) => {
+        Err(err) => {
+            set_err_msg(vtab, err.description());
             ffi::SQLITE_ERROR
         }
     }
@@ -243,6 +245,7 @@ unsafe extern "C" fn $rowid(cursor: *mut ffi::sqlite3_vtab_cursor,
 pub unsafe fn cursor_error<T>(cursor: *mut ffi::sqlite3_vtab_cursor,
                               result: Result<T>)
                               -> libc::c_int {
+    use std::error::Error as StdError;
     match result {
         Ok(_) => ffi::SQLITE_OK,
         Err(Error::SqliteFailure(err, s)) => {
@@ -251,8 +254,8 @@ pub unsafe fn cursor_error<T>(cursor: *mut ffi::sqlite3_vtab_cursor,
             }
             err.extended_code
         }
-        Err(_) => {
-            // TODO errMsg
+        Err(err) => {
+            set_err_msg((*cursor).pVtab, err.description());
             ffi::SQLITE_ERROR
         }
     }