diff --git a/Cargo.toml b/Cargo.toml
index 7cdf204..c5114c0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ name = "rusqlite"
 [features]
 load_extension = ["libsqlite3-sys/load_extension"]
 backup = []
+functions = []
 trace = []
 
 [dependencies]
@@ -25,6 +26,7 @@ libc = "~0.2"
 [dev-dependencies]
 tempdir = "~0.3.4"
 lazy_static = "~0.1"
+regex = "~0.1.41"
 
 [dependencies.libsqlite3-sys]
 path = "libsqlite3-sys"
diff --git a/libsqlite3-sys/src/lib.rs b/libsqlite3-sys/src/lib.rs
index 51f33c5..0eeacfa 100644
--- a/libsqlite3-sys/src/lib.rs
+++ b/libsqlite3-sys/src/lib.rs
@@ -94,3 +94,5 @@ pub fn code_to_str(code: c_int) -> &'static str {
 }
 
 pub const SQLITE_CONFIG_LOG  : c_int = 16;
+pub const SQLITE_UTF8  : c_int = 1;
+pub const SQLITE_DETERMINISTIC  : c_int = 0x800;
diff --git a/src/functions.rs b/src/functions.rs
new file mode 100644
index 0000000..fa6220e
--- /dev/null
+++ b/src/functions.rs
@@ -0,0 +1,330 @@
+//! Create or redefine SQL functions
+use std::ffi::{CStr};
+use std::mem;
+use std::ptr;
+use std::str;
+use libc::{c_int, c_double, c_char};
+
+use ffi;
+pub use ffi::sqlite3_context as sqlite3_context;
+pub use ffi::sqlite3_value as sqlite3_value;
+pub use ffi::sqlite3_value_type as sqlite3_value_type;
+pub use ffi::sqlite3_value_numeric_type as sqlite3_value_numeric_type;
+
+use types::Null;
+
+use {SqliteResult, SqliteError, SqliteConnection, str_to_cstring, InnerSqliteConnection};
+
+/// A trait for types that can be converted into the result of an SQL function.
+pub trait ToResult {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context);
+}
+
+macro_rules! raw_to_impl(
+    ($t:ty, $f:ident) => (
+        impl ToResult for $t {
+            unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+                ffi::$f(ctx, *self)
+            }
+        }
+    )
+);
+
+raw_to_impl!(c_int, sqlite3_result_int);
+raw_to_impl!(i64, sqlite3_result_int64);
+raw_to_impl!(c_double, sqlite3_result_double);
+
+impl<'a> ToResult for bool {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        match *self {
+            true => ffi::sqlite3_result_int(ctx, 1),
+            _ => ffi::sqlite3_result_int(ctx, 0),
+        }
+    }
+}
+
+
+impl<'a> ToResult for &'a str {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        let length = self.len();
+        if length > ::std::i32::MAX as usize {
+            ffi::sqlite3_result_error_toobig(ctx);
+            return
+        }
+        match str_to_cstring(self) {
+            Ok(c_str) => ffi::sqlite3_result_text(ctx, c_str.as_ptr(), length as c_int,
+                                                ffi::SQLITE_TRANSIENT()),
+            Err(_)    => ffi::sqlite3_result_error_code(ctx, ffi::SQLITE_MISUSE), // TODO sqlite3_result_error
+        }
+    }
+}
+
+impl ToResult for String {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        (&self[..]).set_result(ctx)
+    }
+}
+
+impl<'a> ToResult for &'a [u8] {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        if self.len() > ::std::i32::MAX as usize {
+            ffi::sqlite3_result_error_toobig(ctx);
+            return
+        }
+        ffi::sqlite3_result_blob(
+            ctx, mem::transmute(self.as_ptr()), self.len() as c_int, ffi::SQLITE_TRANSIENT())
+    }
+}
+
+impl ToResult for Vec<u8> {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        (&self[..]).set_result(ctx)
+    }
+}
+
+impl<T: ToResult> ToResult for Option<T> {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        match *self {
+            None => ffi::sqlite3_result_null(ctx),
+            Some(ref t) => t.set_result(ctx),
+        }
+    }
+}
+
+impl ToResult for Null {
+    unsafe fn set_result(&self, ctx: *mut sqlite3_context) {
+        ffi::sqlite3_result_null(ctx)
+    }
+}
+
+
+// sqlite3_result_error_code, c_int
+// sqlite3_result_error_nomem
+// sqlite3_result_error_toobig
+// sqlite3_result_error, *const c_char, c_int
+// sqlite3_result_zeroblob
+// sqlite3_result_value
+
+/// A trait for types that can be created from a SQLite function parameter value.
+pub trait FromValue: Sized {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<Self>;
+
+    /// FromValue types can implement this method and use sqlite3_value_type to check that
+    /// the type reported by SQLite matches a type suitable for Self. This method is used
+    /// by `???` to confirm that the parameter contains a valid type before
+    /// attempting to retrieve the value.
+    unsafe fn parameter_has_valid_sqlite_type(_: *mut sqlite3_value) -> bool {
+        true
+    }
+}
+
+
+macro_rules! raw_from_impl(
+    ($t:ty, $f:ident, $c:expr) => (
+        impl FromValue for $t {
+            unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<$t> {
+                Ok(ffi::$f(v))
+            }
+
+            unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+                sqlite3_value_numeric_type(v) == $c
+            }
+        }
+    )
+);
+
+raw_from_impl!(c_int, sqlite3_value_int, ffi::SQLITE_INTEGER);
+raw_from_impl!(i64, sqlite3_value_int64, ffi::SQLITE_INTEGER);
+
+impl FromValue for bool {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<bool> {
+        match ffi::sqlite3_value_int(v) {
+            0 => Ok(false),
+            _ => Ok(true),
+        }
+    }
+
+    unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+        sqlite3_value_numeric_type(v) == ffi::SQLITE_INTEGER
+    }
+}
+
+impl FromValue for c_double {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<c_double> {
+        Ok(ffi::sqlite3_value_double(v))
+    }
+
+    unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+        sqlite3_value_numeric_type(v) == ffi::SQLITE_FLOAT || sqlite3_value_numeric_type(v) == ffi::SQLITE_INTEGER
+    }
+}
+
+impl FromValue for String {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<String> {
+        let c_text = ffi::sqlite3_value_text(v);
+        if c_text.is_null() {
+            Ok("".to_string())
+        } else {
+            let c_slice = CStr::from_ptr(c_text as *const c_char).to_bytes();
+            let utf8_str = str::from_utf8(c_slice);
+            utf8_str
+                .map(|s| { s.to_string() })
+                .map_err(|e| { SqliteError{code: 0, message: e.to_string()} })
+        }
+    }
+
+    unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+        sqlite3_value_type(v) == ffi::SQLITE_TEXT
+    }
+}
+
+impl FromValue for Vec<u8> {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<Vec<u8>> {
+        use std::slice::from_raw_parts;
+        let c_blob = ffi::sqlite3_value_blob(v);
+        let len = ffi::sqlite3_value_bytes(v);
+
+        assert!(len >= 0, "unexpected negative return from sqlite3_value_bytes");
+        let len = len as usize;
+
+        Ok(from_raw_parts(mem::transmute(c_blob), len).to_vec())
+    }
+
+    unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+        sqlite3_value_type(v) == ffi::SQLITE_BLOB
+    }
+}
+
+impl<T: FromValue> FromValue for Option<T> {
+    unsafe fn parameter_value(v: *mut sqlite3_value) -> SqliteResult<Option<T>> {
+        if sqlite3_value_type(v) == ffi::SQLITE_NULL {
+            Ok(None)
+        } else {
+            FromValue::parameter_value(v).map(|t| Some(t))
+        }
+    }
+
+    unsafe fn parameter_has_valid_sqlite_type(v: *mut sqlite3_value) -> bool {
+        sqlite3_value_type(v) == ffi::SQLITE_NULL ||
+            T::parameter_has_valid_sqlite_type(v)
+    }
+}
+
+// sqlite3_user_data
+// sqlite3_get_auxdata
+// sqlite3_set_auxdata
+
+pub type ScalarFunc =
+    Option<extern "C" fn (ctx: *mut sqlite3_context, argc: c_int, argv: *mut *mut sqlite3_value)>;
+
+impl SqliteConnection {
+    // TODO pApp
+    pub fn create_scalar_function(&self, fn_name: &str, n_arg: c_int, deterministic: bool, x_func: ScalarFunc) -> SqliteResult<()> {
+        self.db.borrow_mut().create_scalar_function(fn_name, n_arg, deterministic, x_func)
+    }
+}
+
+impl InnerSqliteConnection {
+    pub fn create_scalar_function(&mut self, fn_name: &str, n_arg: c_int, deterministic: bool, x_func: ScalarFunc) -> SqliteResult<()> {
+        let c_name = try!(str_to_cstring(fn_name));
+        let mut flags = ffi::SQLITE_UTF8;
+        if deterministic {
+            flags |= ffi::SQLITE_DETERMINISTIC;
+        }
+        let r = unsafe {
+            ffi::sqlite3_create_function_v2(self.db(), c_name.as_ptr(), n_arg, flags, ptr::null_mut(), x_func, None, None, None)
+        };
+        self.decode_result(r)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    extern crate regex;
+
+    use std::boxed::Box;
+    use std::ffi::{CString};
+    use std::mem;
+    use libc::{c_int, c_double, c_void};
+    use self::regex::Regex;
+
+    use SqliteConnection;
+    use ffi;
+    use ffi::sqlite3_context as sqlite3_context;
+    use ffi::sqlite3_value as sqlite3_value;
+    use functions::{FromValue,ToResult};
+
+    extern "C" fn half(ctx: *mut sqlite3_context, _: c_int, argv: *mut *mut sqlite3_value) {
+        unsafe {
+            let arg = *argv.offset(0);
+            if c_double::parameter_has_valid_sqlite_type(arg) {
+                let value = c_double::parameter_value(arg).unwrap() / 2f64;
+                value.set_result(ctx);
+            } else {
+                ffi::sqlite3_result_error_code(ctx, ffi::SQLITE_MISMATCH);
+            }
+        }
+    }
+
+    #[test]
+    fn test_half() {
+        let db = SqliteConnection::open_in_memory().unwrap();
+        db.create_scalar_function("half", 1, true, Some(half)).unwrap();
+        let result = db.query_row("SELECT half(6)",
+                                           &[],
+                                           |r| r.get::<f64>(0));
+
+        assert_eq!(3f64, result.unwrap());
+    }
+
+    extern "C" fn regexp_free(raw: *mut c_void) {
+        unsafe {
+            Box::from_raw(raw);
+        }
+    }
+
+    extern "C" fn regexp(ctx: *mut sqlite3_context, _: c_int, argv: *mut *mut sqlite3_value) {
+        unsafe {
+            let mut re_ptr = ffi::sqlite3_get_auxdata(ctx, 0) as *const Regex;
+            let mut re_opt = None;
+            if re_ptr.is_null() {
+                let raw = String::parameter_value(*argv.offset(0));
+                if raw.is_err() {
+                    let msg = CString::new(format!("{}", raw.unwrap_err())).unwrap();
+                    ffi::sqlite3_result_error(ctx, msg.as_ptr(), -1);
+                    return
+                }
+                let comp = Regex::new(raw.unwrap().as_ref());
+                if comp.is_err() {
+                    let msg = CString::new(format!("{}", comp.unwrap_err())).unwrap();
+                    ffi::sqlite3_result_error(ctx, msg.as_ptr(), -1);
+                    return
+                }
+                let re = comp.unwrap();
+                re_ptr = &re as *const Regex;
+                re_opt = Some(re);
+            }
+
+            let text = String::parameter_value(*argv.offset(1));
+            if text.is_ok() {
+                let text = text.unwrap();
+                (*re_ptr).is_match(text.as_ref()).set_result(ctx);
+            }
+
+            if re_opt.is_some() {
+                ffi::sqlite3_set_auxdata(ctx, 0, mem::transmute(Box::into_raw(Box::new(re_opt.unwrap()))), Some(regexp_free));
+            }
+        }
+    }
+
+    #[test]
+    fn test_regexp() {
+        let db = SqliteConnection::open_in_memory().unwrap();
+        db.create_scalar_function("regexp", 2, true, Some(regexp)).unwrap();
+        let result = db.query_row("SELECT regexp('l.s[aeiouy]', 'lisa')",
+                                           &[],
+                                           |r| r.get::<bool>(0));
+
+        assert_eq!(true, result.unwrap());
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 397d615..f32165d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,6 +85,7 @@ mod transaction;
 #[cfg(feature = "load_extension")]mod load_extension_guard;
 #[cfg(feature = "trace")]pub mod trace;
 #[cfg(feature = "backup")]pub mod backup;
+#[cfg(feature = "functions")] pub mod functions;
 
 /// A typedef of the result returned by many methods.
 pub type SqliteResult<T> = Result<T, SqliteError>;
diff --git a/src/types.rs b/src/types.rs
index f102f8a..ddc0234 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -100,6 +100,15 @@ raw_to_impl!(c_int, sqlite3_bind_int);
 raw_to_impl!(i64, sqlite3_bind_int64);
 raw_to_impl!(c_double, sqlite3_bind_double);
 
+impl ToSql for bool {
+    unsafe fn bind_parameter(&self, stmt: *mut sqlite3_stmt, col: c_int) -> c_int {
+        match *self {
+            true => ffi::sqlite3_bind_int(stmt, col, 1),
+            _ => ffi::sqlite3_bind_int(stmt, col, 0),
+        }
+    }
+}
+
 impl<'a> ToSql for &'a str {
     unsafe fn bind_parameter(&self, stmt: *mut sqlite3_stmt, col: c_int) -> c_int {
         let length = self.len();
@@ -203,6 +212,19 @@ raw_from_impl!(c_int, sqlite3_column_int, ffi::SQLITE_INTEGER);
 raw_from_impl!(i64, sqlite3_column_int64, ffi::SQLITE_INTEGER);
 raw_from_impl!(c_double, sqlite3_column_double, ffi::SQLITE_FLOAT);
 
+impl FromSql for bool {
+    unsafe fn column_result(stmt: *mut sqlite3_stmt, col: c_int) -> SqliteResult<bool> {
+        match ffi::sqlite3_column_int(stmt, col) {
+            0 => Ok(false),
+            _ => Ok(true),
+        }
+    }
+
+    unsafe fn column_has_valid_sqlite_type(stmt: *mut sqlite3_stmt, col: c_int) -> bool {
+        sqlite3_column_type(stmt, col) == ffi::SQLITE_INTEGER
+    }
+}
+
 impl FromSql for String {
     unsafe fn column_result(stmt: *mut sqlite3_stmt, col: c_int) -> SqliteResult<String> {
         let c_text = ffi::sqlite3_column_text(stmt, col);