Merge pull request #249 from jgallagher/reorganize-extract-row

Reorganize: Extract Row/Rows and helper types into their own mod file.

src/cache.rs

@@ -176,16 +176,14 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
         }
         assert_eq!(1, cache.len());
 
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
         }
         assert_eq!(1, cache.len());
 
@@ -203,8 +201,7 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
         }
         assert_eq!(1, cache.len());
 
@@ -214,8 +211,7 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
         }
         assert_eq!(0, cache.len());
 
@@ -223,8 +219,7 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
         }
         assert_eq!(1, cache.len());
     }
@@ -238,8 +233,7 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(0, cache.len());
-            assert_eq!(0,
-                       stmt.query(&[]).unwrap().get_expected_row().unwrap().get::<i32, i64>(0));
+            assert_eq!(0, stmt.query_row(&[], |r| r.get::<i32, i64>(0)).unwrap());
             stmt.discard();
         }
         assert_eq!(0, cache.len());

src/lib.rs

@@ -62,7 +62,6 @@ extern crate lazy_static;
 
 use std::default::Default;
 use std::convert;
-use std::marker::PhantomData;
 use std::mem;
 use std::ptr;
 use std::fmt;
@@ -75,7 +74,7 @@ use std::sync::{Once, ONCE_INIT};
 use std::sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
 use std::os::raw::{c_int, c_char};
 
-use types::{ToSql, FromSql, FromSqlError, ValueRef};
+use types::{ToSql, ValueRef};
 use error::{error_from_sqlite_code, error_from_handle};
 use raw_statement::RawStatement;
 use cache::StatementCache;
@@ -83,6 +82,9 @@ use cache::StatementCache;
 pub use statement::Statement;
 use statement::StatementCrateImpl;
 
+pub use row::{Row, Rows, MappedRows, AndThenRows};
+use row::RowsCrateImpl;
+
 #[allow(deprecated)]
 pub use transaction::{SqliteTransaction, SqliteTransactionBehavior};
 pub use transaction::{DropBehavior, Savepoint, Transaction, TransactionBehavior};
@@ -105,6 +107,7 @@ mod transaction;
 mod cache;
 mod error;
 mod raw_statement;
+mod row;
 mod statement;
 #[cfg(feature = "load_extension")]
 mod load_extension_guard;
@@ -865,185 +868,15 @@ impl Drop for InnerConnection {
 #[deprecated(since = "0.6.0", note = "Use Statement instead")]
 pub type SqliteStatement<'conn> = Statement<'conn>;
 
-/// An iterator over the mapped resulting rows of a query.
-pub struct MappedRows<'stmt, F> {
-    rows: Rows<'stmt>,
-    map: F,
-}
-
-impl<'stmt, T, F> Iterator for MappedRows<'stmt, F>
-    where F: FnMut(&Row) -> T
-{
-    type Item = Result<T>;
-
-    fn next(&mut self) -> Option<Result<T>> {
-        let map = &mut self.map;
-        self.rows.next().map(|row_result| row_result.map(|row| (map)(&row)))
-    }
-}
-
-/// An iterator over the mapped resulting rows of a query, with an Error type
-/// unifying with Error.
-pub struct AndThenRows<'stmt, F> {
-    rows: Rows<'stmt>,
-    map: F,
-}
-
-impl<'stmt, T, E, F> Iterator for AndThenRows<'stmt, F>
-    where E: convert::From<Error>,
-          F: FnMut(&Row) -> result::Result<T, E>
-{
-    type Item = result::Result<T, E>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let map = &mut self.map;
-        self.rows.next().map(|row_result| {
-            row_result.map_err(E::from)
-                .and_then(|row| (map)(&row))
-        })
-    }
-}
-
 /// Old name for `Rows`. `SqliteRows` is deprecated.
 #[deprecated(since = "0.6.0", note = "Use Rows instead")]
 pub type SqliteRows<'stmt> = Rows<'stmt>;
 
-/// An handle for the resulting rows of a query.
-pub struct Rows<'stmt> {
-    stmt: Option<&'stmt Statement<'stmt>>,
-}
-
-#[allow(should_implement_trait)]
-impl<'stmt> Rows<'stmt> {
-    fn new(stmt: &'stmt Statement<'stmt>) -> Rows<'stmt> {
-        Rows { stmt: Some(stmt) }
-    }
-
-    fn get_expected_row<'a>(&'a mut self) -> Result<Row<'a, 'stmt>> {
-        match self.next() {
-            Some(row) => row,
-            None => Err(Error::QueryReturnedNoRows),
-        }
-    }
-
-    fn reset(&mut self) {
-        if let Some(stmt) = self.stmt.take() {
-            stmt.reset();
-        }
-    }
-
-    /// Attempt to get the next row from the query. Returns `Some(Ok(Row))` if there
-    /// is another row, `Some(Err(...))` if there was an error getting the next
-    /// row, and `None` if all rows have been retrieved.
-    ///
-    /// ## Note
-    ///
-    /// This interface is not compatible with Rust's `Iterator` trait, because the
-    /// lifetime of the returned row is tied to the lifetime of `self`. This is a
-    /// "streaming iterator". For a more natural interface, consider using `query_map`
-    /// or `query_and_then` instead, which return types that implement `Iterator`.
-    pub fn next<'a>(&'a mut self) -> Option<Result<Row<'a, 'stmt>>> {
-        self.stmt.and_then(|stmt| match stmt.step() {
-            Ok(true) => Some(Ok(Row {
-                stmt: stmt,
-                phantom: PhantomData,
-            })),
-            Ok(false) => {
-                self.reset();
-                None
-            }
-            Err(err) => {
-                self.reset();
-                Some(Err(err))
-            }
-        })
-    }
-}
-
-impl<'stmt> Drop for Rows<'stmt> {
-    fn drop(&mut self) {
-        self.reset();
-    }
-}
 
 /// Old name for `Row`. `SqliteRow` is deprecated.
 #[deprecated(since = "0.6.0", note = "Use Row instead")]
 pub type SqliteRow<'a, 'stmt> = Row<'a, 'stmt>;
 
-/// A single result row of a query.
-pub struct Row<'a, 'stmt> {
-    stmt: &'stmt Statement<'stmt>,
-    phantom: PhantomData<&'a ()>,
-}
-
-impl<'a, 'stmt> Row<'a, 'stmt> {
-    /// Get the value of a particular column of the result row.
-    ///
-    /// ## Failure
-    ///
-    /// Panics if calling `row.get_checked(idx)` would return an error, including:
-    ///
-    ///    * If the underlying SQLite column type is not a valid type as a source for `T`
-    ///    * If the underlying SQLite integral value is outside the range representable by `T`
-    ///    * If `idx` is outside the range of columns in the returned query
-    pub fn get<I: RowIndex, T: FromSql>(&self, idx: I) -> T {
-        self.get_checked(idx).unwrap()
-    }
-
-    /// Get the value of a particular column of the result row.
-    ///
-    /// ## Failure
-    ///
-    /// Returns an `Error::InvalidColumnType` if the underlying SQLite column
-    /// type is not a valid type as a source for `T`.
-    ///
-    /// Returns an `Error::InvalidColumnIndex` if `idx` is outside the valid column range
-    /// for this row.
-    ///
-    /// Returns an `Error::InvalidColumnName` if `idx` is not a valid column name
-    /// for this row.
-    pub fn get_checked<I: RowIndex, T: FromSql>(&self, idx: I) -> Result<T> {
-        let idx = try!(idx.idx(self.stmt));
-        let value = self.stmt.value_ref(idx);
-        FromSql::column_result(value).map_err(|err| match err {
-            FromSqlError::InvalidType => Error::InvalidColumnType(idx, value.data_type()),
-            FromSqlError::OutOfRange(i) => Error::IntegralValueOutOfRange(idx, i),
-            FromSqlError::Other(err) => {
-                Error::FromSqlConversionFailure(idx as usize, value.data_type(), err)
-            }
-        })
-    }
-
-    /// Return the number of columns in the current row.
-    pub fn column_count(&self) -> i32 {
-        self.stmt.column_count()
-    }
-}
-
-/// A trait implemented by types that can index into columns of a row.
-pub trait RowIndex {
-    /// Returns the index of the appropriate column, or `None` if no such
-    /// column exists.
-    fn idx(&self, stmt: &Statement) -> Result<i32>;
-}
-
-impl RowIndex for i32 {
-    #[inline]
-    fn idx(&self, stmt: &Statement) -> Result<i32> {
-        if *self < 0 || *self >= stmt.column_count() {
-            Err(Error::InvalidColumnIndex(*self))
-        } else {
-            Ok(*self)
-        }
-    }
-}
-
-impl<'a> RowIndex for &'a str {
-    #[inline]
-    fn idx(&self, stmt: &Statement) -> Result<i32> {
-        stmt.column_index(*self)
-    }
-}
 
 #[cfg(test)]
 mod test {

src/row.rs

@@ -0,0 +1,222 @@
+use std::{convert, result};
+use std::marker::PhantomData;
+
+use super::{Statement, Error, Result};
+use types::{FromSql, FromSqlError};
+use statement::StatementCrateImpl;
+
+/// An handle for the resulting rows of a query.
+pub struct Rows<'stmt> {
+    stmt: Option<&'stmt Statement<'stmt>>,
+}
+
+impl<'stmt> Rows<'stmt> {
+    fn reset(&mut self) {
+        if let Some(stmt) = self.stmt.take() {
+            stmt.reset();
+        }
+    }
+
+    /// Attempt to get the next row from the query. Returns `Some(Ok(Row))` if there
+    /// is another row, `Some(Err(...))` if there was an error getting the next
+    /// row, and `None` if all rows have been retrieved.
+    ///
+    /// ## Note
+    ///
+    /// This interface is not compatible with Rust's `Iterator` trait, because the
+    /// lifetime of the returned row is tied to the lifetime of `self`. This is a
+    /// "streaming iterator". For a more natural interface, consider using `query_map`
+    /// or `query_and_then` instead, which return types that implement `Iterator`.
+    pub fn next<'a>(&'a mut self) -> Option<Result<Row<'a, 'stmt>>> {
+        self.stmt.and_then(|stmt| match stmt.step() {
+            Ok(true) => {
+                Some(Ok(Row {
+                    stmt: stmt,
+                    phantom: PhantomData,
+                }))
+            }
+            Ok(false) => {
+                self.reset();
+                None
+            }
+            Err(err) => {
+                self.reset();
+                Some(Err(err))
+            }
+        })
+    }
+}
+
+// TODO: This trait lets us have "pub(crate)" visibility on some methods. Remove this
+// once pub(crate) is stable.
+pub trait RowsCrateImpl<'stmt> {
+    fn new(stmt: &'stmt Statement<'stmt>) -> Rows<'stmt>;
+    fn get_expected_row<'a>(&'a mut self) -> Result<Row<'a, 'stmt>>;
+}
+
+impl<'stmt> RowsCrateImpl<'stmt> for Rows<'stmt> {
+    fn new(stmt: &'stmt Statement<'stmt>) -> Rows<'stmt> {
+        Rows { stmt: Some(stmt) }
+    }
+
+    fn get_expected_row<'a>(&'a mut self) -> Result<Row<'a, 'stmt>> {
+        match self.next() {
+            Some(row) => row,
+            None => Err(Error::QueryReturnedNoRows),
+        }
+    }
+}
+
+impl<'stmt> Drop for Rows<'stmt> {
+    fn drop(&mut self) {
+        self.reset();
+    }
+}
+
+/// An iterator over the mapped resulting rows of a query.
+pub struct MappedRows<'stmt, F> {
+    rows: Rows<'stmt>,
+    map: F,
+}
+
+// TODO: This trait lets us have "pub(crate)" visibility on some methods. Remove this
+// once pub(crate) is stable.
+pub trait MappedRowsCrateImpl<'stmt, T, F> {
+    fn new(rows: Rows<'stmt>, f: F) -> MappedRows<'stmt, F>;
+}
+
+impl<'stmt, T, F> MappedRowsCrateImpl<'stmt, T, F> for MappedRows<'stmt, F>
+    where F: FnMut(&Row) -> T
+{
+    fn new(rows: Rows<'stmt>, f: F) -> MappedRows<'stmt, F> {
+        MappedRows {
+            rows: rows,
+            map: f,
+        }
+    }
+}
+
+impl<'conn, T, F> Iterator for MappedRows<'conn, F>
+    where F: FnMut(&Row) -> T
+{
+    type Item = Result<T>;
+
+    fn next(&mut self) -> Option<Result<T>> {
+        let map = &mut self.map;
+        self.rows.next().map(|row_result| row_result.map(|row| (map)(&row)))
+    }
+}
+
+/// An iterator over the mapped resulting rows of a query, with an Error type
+/// unifying with Error.
+pub struct AndThenRows<'stmt, F> {
+    rows: Rows<'stmt>,
+    map: F,
+}
+
+// TODO: This trait lets us have "pub(crate)" visibility on some methods. Remove this
+// once pub(crate) is stable.
+pub trait AndThenRowsCrateImpl<'stmt, T, E, F> {
+    fn new(rows: Rows<'stmt>, f: F) -> AndThenRows<'stmt, F>;
+}
+
+impl<'stmt, T, E, F> AndThenRowsCrateImpl<'stmt, T, E, F> for AndThenRows<'stmt, F>
+    where F: FnMut(&Row) -> result::Result<T, E>
+{
+    fn new(rows: Rows<'stmt>, f: F) -> AndThenRows<'stmt, F> {
+        AndThenRows {
+            rows: rows,
+            map: f,
+        }
+    }
+}
+
+impl<'stmt, T, E, F> Iterator for AndThenRows<'stmt, F>
+    where E: convert::From<Error>,
+          F: FnMut(&Row) -> result::Result<T, E>
+{
+    type Item = result::Result<T, E>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let map = &mut self.map;
+        self.rows.next().map(|row_result| {
+            row_result.map_err(E::from)
+                .and_then(|row| (map)(&row))
+        })
+    }
+}
+
+/// A single result row of a query.
+pub struct Row<'a, 'stmt> {
+    stmt: &'stmt Statement<'stmt>,
+    phantom: PhantomData<&'a ()>,
+}
+
+impl<'a, 'stmt> Row<'a, 'stmt> {
+    /// Get the value of a particular column of the result row.
+    ///
+    /// ## Failure
+    ///
+    /// Panics if calling `row.get_checked(idx)` would return an error, including:
+    ///
+    ///    * If the underlying SQLite column type is not a valid type as a source for `T`
+    ///    * If the underlying SQLite integral value is outside the range representable by `T`
+    ///    * If `idx` is outside the range of columns in the returned query
+    pub fn get<I: RowIndex, T: FromSql>(&self, idx: I) -> T {
+        self.get_checked(idx).unwrap()
+    }
+
+    /// Get the value of a particular column of the result row.
+    ///
+    /// ## Failure
+    ///
+    /// Returns an `Error::InvalidColumnType` if the underlying SQLite column
+    /// type is not a valid type as a source for `T`.
+    ///
+    /// Returns an `Error::InvalidColumnIndex` if `idx` is outside the valid column range
+    /// for this row.
+    ///
+    /// Returns an `Error::InvalidColumnName` if `idx` is not a valid column name
+    /// for this row.
+    pub fn get_checked<I: RowIndex, T: FromSql>(&self, idx: I) -> Result<T> {
+        let idx = try!(idx.idx(self.stmt));
+        let value = self.stmt.value_ref(idx);
+        FromSql::column_result(value).map_err(|err| match err {
+            FromSqlError::InvalidType => Error::InvalidColumnType(idx, value.data_type()),
+            FromSqlError::OutOfRange(i) => Error::IntegralValueOutOfRange(idx, i),
+            FromSqlError::Other(err) => {
+                Error::FromSqlConversionFailure(idx as usize, value.data_type(), err)
+            }
+        })
+    }
+
+    /// Return the number of columns in the current row.
+    pub fn column_count(&self) -> i32 {
+        self.stmt.column_count()
+    }
+}
+
+/// A trait implemented by types that can index into columns of a row.
+pub trait RowIndex {
+    /// Returns the index of the appropriate column, or `None` if no such
+    /// column exists.
+    fn idx(&self, stmt: &Statement) -> Result<i32>;
+}
+
+impl RowIndex for i32 {
+    #[inline]
+    fn idx(&self, stmt: &Statement) -> Result<i32> {
+        if *self < 0 || *self >= stmt.column_count() {
+            Err(Error::InvalidColumnIndex(*self))
+        } else {
+            Ok(*self)
+        }
+    }
+}
+
+impl<'a> RowIndex for &'a str {
+    #[inline]
+    fn idx(&self, stmt: &Statement) -> Result<i32> {
+        stmt.column_index(*self)
+    }
+}

src/statement.rs

@@ -7,6 +7,7 @@ use super::ffi;
 use super::{Connection, RawStatement, Result, Error, ValueRef, Row, Rows, AndThenRows, MappedRows};
 use super::str_to_cstring;
 use types::{ToSql, ToSqlOutput};
+use row::{RowsCrateImpl, MappedRowsCrateImpl, AndThenRowsCrateImpl};
 
 /// A prepared statement.
 pub struct Statement<'conn> {
@@ -211,12 +212,8 @@ impl<'conn> Statement<'conn> {
     pub fn query_map<'a, T, F>(&'a mut self, params: &[&ToSql], f: F) -> Result<MappedRows<'a, F>>
         where F: FnMut(&Row) -> T
     {
-        let row_iter = try!(self.query(params));
-
-        Ok(MappedRows {
-            rows: row_iter,
-            map: f,
-        })
+        let rows = self.query(params)?;
+        Ok(MappedRows::new(rows, f))
     }
 
     /// Execute the prepared statement with named parameter(s), returning an iterator over the
@@ -251,11 +248,8 @@ impl<'conn> Statement<'conn> {
                                      -> Result<MappedRows<'a, F>>
         where F: FnMut(&Row) -> T
     {
-        let rows = try!(self.query_named(params));
-        Ok(MappedRows {
-            rows: rows,
-            map: f,
-        })
+        let rows = self.query_named(params)?;
+        Ok(MappedRows::new(rows, f))
     }
 
     /// Executes the prepared statement and maps a function over the resulting
@@ -272,12 +266,8 @@ impl<'conn> Statement<'conn> {
         where E: convert::From<Error>,
               F: FnMut(&Row) -> result::Result<T, E>
     {
-        let row_iter = try!(self.query(params));
-
-        Ok(AndThenRows {
-            rows: row_iter,
-            map: f,
-        })
+        let rows = self.query(params)?;
+        Ok(AndThenRows::new(rows, f))
     }
 
     /// Execute the prepared statement with named parameter(s), returning an iterator over the
@@ -322,11 +312,8 @@ impl<'conn> Statement<'conn> {
         where E: convert::From<Error>,
               F: FnMut(&Row) -> result::Result<T, E>
     {
-        let rows = try!(self.query_named(params));
-        Ok(AndThenRows {
-            rows: rows,
-            map: f,
-        })
+        let rows = self.query_named(params)?;
+        Ok(AndThenRows::new(rows, f))
     }
 
     /// Return `true` if a query in the SQL statement it executes returns one or more rows