Add Rows::map method

Cargo.toml

@@ -58,6 +58,7 @@ serde_json = { version = "1.0", optional = true }
 csv = { version = "1.0", optional = true }
 lazy_static = { version = "1.0", optional = true }
 byteorder = { version = "1.2", features = ["i128"], optional = true }
+fallible-iterator = "0.1"
 fallible-streaming-iterator = "0.1"
 memchr = "2.2.0"
 

src/cache.rs

@@ -151,6 +151,7 @@ impl StatementCache {
 
 #[cfg(test)]
 mod test {
+    use fallible_iterator::FallibleIterator;
     use super::StatementCache;
     use crate::{Connection, NO_PARAMS};
 
@@ -277,12 +278,9 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(
-                1i32,
+                Ok(Some(1i32)),
-                stmt.query_map::<i32, _, _>(NO_PARAMS, |r| r.get(0))
+                stmt.query(NO_PARAMS).unwrap().map(|r| r.get(0))
-                    .unwrap()
                     .next()
-                    .unwrap()
-                    .unwrap()
             );
         }
 
@@ -297,12 +295,9 @@ mod test {
         {
             let mut stmt = db.prepare_cached(sql).unwrap();
             assert_eq!(
-                (1i32, 2i32),
+                Ok(Some((1i32, 2i32))),
-                stmt.query_map(NO_PARAMS, |r| Ok((r.get(0)?, r.get(1)?)))
+                stmt.query(NO_PARAMS).unwrap().map(|r| Ok((r.get(0)?, r.get(1)?)))
-                    .unwrap()
                     .next()
-                    .unwrap()
-                    .unwrap()
             );
         }
     }

src/lib.rs

@@ -77,8 +77,6 @@ use std::str;
 use std::sync::atomic::Ordering;
 use std::sync::{Arc, Mutex};
 
-pub use fallible_streaming_iterator::FallibleStreamingIterator;
-
 use crate::cache::StatementCache;
 use crate::inner_connection::{InnerConnection, BYPASS_SQLITE_INIT};
 use crate::raw_statement::RawStatement;
@@ -846,6 +844,7 @@ unsafe fn db_filename(_: *mut ffi::sqlite3) -> Option<PathBuf> {
 
 #[cfg(test)]
 mod test {
+    use fallible_iterator::FallibleIterator;
     use self::tempdir::TempDir;
     pub use super::*;
     use crate::ffi;
@@ -1132,8 +1131,7 @@ mod test {
 
         let mut query = db.prepare("SELECT x, y FROM foo ORDER BY x DESC").unwrap();
         let results: Result<Vec<String>> = query
-            .query_map(NO_PARAMS, |row| row.get(1))
+            .query(NO_PARAMS).unwrap().map(|row| row.get(1))
-            .unwrap()
             .collect();
 
         assert_eq!(results.unwrap().concat(), "hello, world!");
@@ -1322,7 +1320,7 @@ mod test {
             .prepare("SELECT interrupt() FROM (SELECT 1 UNION SELECT 2 UNION SELECT 3)")
             .unwrap();
 
-        let result: Result<Vec<i32>> = stmt.query_map(NO_PARAMS, |r| r.get(0)).unwrap().collect();
+        let result: Result<Vec<i32>> = stmt.query(NO_PARAMS).unwrap().map(|r| r.get(0)).collect();
 
         match result.unwrap_err() {
             Error::SqliteFailure(err, _) => {

src/row.rs

@@ -1,6 +1,8 @@
+use fallible_iterator::FallibleIterator;
+use fallible_streaming_iterator::FallibleStreamingIterator;
 use std::{convert, result};
 
-use super::{Error, FallibleStreamingIterator, Result, Statement};
+use super::{Error, Result, Statement};
 use crate::types::{FromSql, FromSqlError, ValueRef};
 
 /// An handle for the resulting rows of a query.
@@ -32,6 +34,13 @@ impl<'stmt> Rows<'stmt> {
         self.advance()?;
         Ok((*self).get())
     }
+
+    pub fn map<F, B>(self, f: F) -> Map<'stmt, F>
+    where
+        F: FnMut(&Row<'_>) -> Result<B>,
+    {
+        Map { rows: self, f: f }
+    }
 }
 
 impl<'stmt> Rows<'stmt> {
@@ -56,6 +65,26 @@ impl Drop for Rows<'_> {
     }
 }
 
+pub struct Map<'stmt, F> {
+    rows: Rows<'stmt>,
+    f: F,
+}
+
+impl<F, B> FallibleIterator for Map<'_, F>
+where
+    F: FnMut(&Row<'_>) -> Result<B>,
+{
+    type Error = Error;
+    type Item = B;
+
+    fn next(&mut self) -> Result<Option<B>> {
+        match self.rows.next()? {
+            Some(v) => Ok(Some((self.f)(v)?)),
+            None => Ok(None),
+        }
+    }
+}
+
 /// An iterator over the mapped resulting rows of a query.
 pub struct MappedRows<'stmt, F> {
     rows: Rows<'stmt>,

src/session.rs

@@ -10,13 +10,13 @@ use std::panic::{catch_unwind, RefUnwindSafe};
 use std::ptr;
 use std::slice::{from_raw_parts, from_raw_parts_mut};
 
+use fallible_streaming_iterator::FallibleStreamingIterator;
+
 use crate::error::error_from_sqlite_code;
 use crate::ffi;
 use crate::hooks::Action;
 use crate::types::ValueRef;
-use crate::{
+use crate::{errmsg_to_string, str_to_cstring, Connection, DatabaseName, Result};
-    errmsg_to_string, str_to_cstring, Connection, DatabaseName, FallibleStreamingIterator, Result,
-};
 
 // https://sqlite.org/session.html
 
@@ -720,10 +720,11 @@ unsafe extern "C" fn x_output(p_out: *mut c_void, data: *const c_void, len: c_in
 #[cfg(test)]
 mod test {
     use std::sync::atomic::{AtomicBool, Ordering};
+    use fallible_streaming_iterator::FallibleStreamingIterator;
 
     use super::{Changeset, ChangesetIter, ConflictAction, ConflictType, Session};
     use crate::hooks::Action;
-    use crate::{Connection, FallibleStreamingIterator};
+    use crate::Connection;
 
     fn one_changeset() -> Changeset {
         let db = Connection::open_in_memory().unwrap();

src/statement.rs

@@ -168,7 +168,7 @@ impl Statement<'_> {
     /// ## Example
     ///
     /// ```rust,no_run
-    /// # use rusqlite::{Connection, FallibleStreamingIterator, Result, NO_PARAMS};
+    /// # use rusqlite::{Connection, Result, NO_PARAMS};
     /// fn get_names(conn: &Connection) -> Result<Vec<String>> {
     ///     let mut stmt = conn.prepare("SELECT name FROM people")?;
     ///     let mut rows = stmt.query(NO_PARAMS)?;
@@ -204,7 +204,7 @@ impl Statement<'_> {
     /// ## Example
     ///
     /// ```rust,no_run
-    /// # use rusqlite::{Connection, FallibleStreamingIterator, Result};
+    /// # use rusqlite::{Connection, Result};
     /// fn query(conn: &Connection) -> Result<()> {
     ///     let mut stmt = conn.prepare("SELECT * FROM test where name = :name")?;
     ///     let mut rows = stmt.query_named(&[(":name", &"one")])?;
@@ -219,7 +219,7 @@ impl Statement<'_> {
     /// and so the above example could also be written as:
     ///
     /// ```rust,no_run
-    /// # use rusqlite::{Connection, FallibleStreamingIterator, Result, named_params};
+    /// # use rusqlite::{Connection, Result, named_params};
     /// fn query(conn: &Connection) -> Result<()> {
     ///     let mut stmt = conn.prepare("SELECT * FROM test where name = :name")?;
     ///     let mut rows = stmt.query_named(named_params!{ ":name": "one" })?;

src/vtab/csvtab.rs

@@ -345,6 +345,7 @@ impl From<csv::Error> for Error {
 
 #[cfg(test)]
 mod test {
+    use fallible_iterator::FallibleIterator;
     use crate::vtab::csvtab;
     use crate::{Connection, Result, NO_PARAMS};
 
@@ -363,8 +364,7 @@ mod test {
             }
 
             let ids: Result<Vec<i32>> = s
-                .query_map(NO_PARAMS, |row| row.get::<_, i32>(0))
+                .query(NO_PARAMS).unwrap().map(|row| row.get::<_, i32>(0))
-                .unwrap()
                 .collect();
             let sum = ids.unwrap().iter().sum::<i32>();
             assert_eq!(sum, 15);