Silent some clippy warnings (#924)

* allow(clippy::upper_case_acronyms) for rust enum entries that match
  SQLite constants.
* allow(clippy::needless_return) for collation_needed_callback until we
  find a way to propagate the error.

src/vtab/csvtab.rs

@@ -48,12 +48,12 @@ use crate::{Connection, Error, Result};
 /// ```
 pub fn load_module(conn: &Connection) -> Result<()> {
     let aux: Option<()> = None;
-    conn.create_module("csv", read_only_module::<CSVTab>(), aux)
+    conn.create_module("csv", read_only_module::<CsvTab>(), aux)
 }
 
 /// An instance of the CSV virtual table
 #[repr(C)]
-struct CSVTab {
+struct CsvTab {
     /// Base class. Must be first
     base: ffi::sqlite3_vtab,
     /// Name of the CSV file
@@ -65,7 +65,7 @@ struct CSVTab {
     offset_first_row: csv::Position,
 }
 
-impl CSVTab {
+impl CsvTab {
     fn reader(&self) -> Result<csv::Reader<File>, csv::Error> {
         csv::ReaderBuilder::new()
             .has_headers(self.has_headers)
@@ -96,20 +96,20 @@ impl CSVTab {
     }
 }
 
-unsafe impl<'vtab> VTab<'vtab> for CSVTab {
+unsafe impl<'vtab> VTab<'vtab> for CsvTab {
     type Aux = ();
-    type Cursor = CSVTabCursor<'vtab>;
+    type Cursor = CsvTabCursor<'vtab>;
 
     fn connect(
         _: &mut VTabConnection,
         _aux: Option<&()>,
         args: &[&[u8]],
-    ) -> Result<(String, CSVTab)> {
+    ) -> Result<(String, CsvTab)> {
         if args.len() < 4 {
             return Err(Error::ModuleError("no CSV file specified".to_owned()));
         }
 
-        let mut vtab = CSVTab {
+        let mut vtab = CsvTab {
             base: ffi::sqlite3_vtab::default(),
             filename: "".to_owned(),
             has_headers: false,
@@ -122,7 +122,7 @@ unsafe impl<'vtab> VTab<'vtab> for CSVTab {
 
         let args = &args[3..];
         for c_slice in args {
-            let (param, value) = CSVTab::parameter(c_slice)?;
+            let (param, value) = CsvTab::parameter(c_slice)?;
             match param {
                 "filename" => {
                     if !Path::new(value).exists() {
@@ -166,7 +166,7 @@ unsafe impl<'vtab> VTab<'vtab> for CSVTab {
                     }
                 }
                 "delimiter" => {
-                    if let Some(b) = CSVTab::parse_byte(value) {
+                    if let Some(b) = CsvTab::parse_byte(value) {
                         vtab.delimiter = b;
                     } else {
                         return Err(Error::ModuleError(format!(
@@ -176,7 +176,7 @@ unsafe impl<'vtab> VTab<'vtab> for CSVTab {
                     }
                 }
                 "quote" => {
-                    if let Some(b) = CSVTab::parse_byte(value) {
+                    if let Some(b) = CsvTab::parse_byte(value) {
                         if b == b'0' {
                             vtab.quote = 0;
                         } else {
@@ -259,16 +259,16 @@ unsafe impl<'vtab> VTab<'vtab> for CSVTab {
         Ok(())
     }
 
-    fn open(&self) -> Result<CSVTabCursor<'_>> {
-        Ok(CSVTabCursor::new(self.reader()?))
+    fn open(&self) -> Result<CsvTabCursor<'_>> {
+        Ok(CsvTabCursor::new(self.reader()?))
     }
 }
 
-impl CreateVTab<'_> for CSVTab {}
+impl CreateVTab<'_> for CsvTab {}
 
 /// A cursor for the CSV virtual table
 #[repr(C)]
-struct CSVTabCursor<'vtab> {
+struct CsvTabCursor<'vtab> {
     /// Base class. Must be first
     base: ffi::sqlite3_vtab_cursor,
     /// The CSV reader object
@@ -278,12 +278,12 @@ struct CSVTabCursor<'vtab> {
     /// Values of the current row
     cols: csv::StringRecord,
     eof: bool,
-    phantom: PhantomData<&'vtab CSVTab>,
+    phantom: PhantomData<&'vtab CsvTab>,
 }
 
-impl CSVTabCursor<'_> {
-    fn new<'vtab>(reader: csv::Reader<File>) -> CSVTabCursor<'vtab> {
-        CSVTabCursor {
+impl CsvTabCursor<'_> {
+    fn new<'vtab>(reader: csv::Reader<File>) -> CsvTabCursor<'vtab> {
+        CsvTabCursor {
             base: ffi::sqlite3_vtab_cursor::default(),
             reader,
             row_number: 0,
@@ -294,12 +294,12 @@ impl CSVTabCursor<'_> {
     }
 
     /// Accessor to the associated virtual table.
-    fn vtab(&self) -> &CSVTab {
-        unsafe { &*(self.base.pVtab as *const CSVTab) }
+    fn vtab(&self) -> &CsvTab {
+        unsafe { &*(self.base.pVtab as *const CsvTab) }
     }
 }
 
-unsafe impl VTabCursor for CSVTabCursor<'_> {
+unsafe impl VTabCursor for CsvTabCursor<'_> {
     // Only a full table scan is supported.  So `filter` simply rewinds to
     // the beginning.
     fn filter(

src/vtab/mod.rs

@@ -261,6 +261,7 @@ pub trait CreateVTab<'vtab>: VTab<'vtab> {
 /// See [Virtual Table Constraint Operator Codes](https://sqlite.org/c3ref/c_index_constraint_eq.html) for details.
 #[derive(Debug, PartialEq)]
 #[allow(non_snake_case, non_camel_case_types, missing_docs)]
+#[allow(clippy::upper_case_acronyms)]
 pub enum IndexConstraintOp {
     SQLITE_INDEX_CONSTRAINT_EQ,
     SQLITE_INDEX_CONSTRAINT_GT,