Add named parameters support

SQLite supports named parameters in either of these forms:
- $NAME
- :NAME
- @NAME

These parameters should be supplied to the query either in a form of a map
or as a list, the key is always iodata:
- #{":myparam" => "value"}
- [{"$myparam", 1}]
- [{text, "@myparam", "value"}]

src/esqlite3.erl

@@ -295,8 +295,17 @@ prepare(#esqlite3{db=Connection}, Sql, PrepareFlags) ->
 %% @doc Bind an array of values as parameters of a prepared statement
 -spec bind(Statement, Args) -> Result when
       Statement :: esqlite3_stmt(),
-      Args :: list(),
+      Args :: list() | map(),
       Result :: ok | {error, _}.
+%% Named parameters
+bind(#esqlite3_stmt{}=Statement, Args) when is_map(Args) ->
+    bind(Statement, maps:to_list(Args));
+bind(#esqlite3_stmt{}=Statement, [{_Type, _ParameterName, _Value} | _] = Args) ->
+    bind2(Statement, Args);
+bind(#esqlite3_stmt{}=Statement, [{ParameterName, _Value} | _] = Args)
+        when is_binary(ParameterName); is_list(ParameterName) ->
+    bind2(Statement, Args);
+%% Anonymous parameters
 bind(#esqlite3_stmt{}=Statement, Args) when is_list(Args) ->
     bind1(Statement, 1, Args).
 
@@ -310,6 +319,33 @@ bind1(Statement, Column, [Arg | Args]) ->
             Error
     end.
 
+bind2(_Statement, []) ->
+    ok;
+bind2(#esqlite3_stmt{stmt=Stmt}=Statement, [{Type, ParameterName, Value} | Args]) ->
+    case esqlite3_nif:bind_parameter_index(Stmt, ParameterName) of
+        {ok, Column} ->
+            case bind_arg(Statement, Column, {Type, Value}) of
+                ok ->
+                    bind2(Statement, Args);
+                {error, _}=Error ->
+                    Error
+            end;
+        error ->
+            {error, named_parameter_not_found}
+    end;
+bind2(#esqlite3_stmt{stmt=Stmt}=Statement, [{ParameterName, Value} | Args]) ->
+    case esqlite3_nif:bind_parameter_index(Stmt, ParameterName) of
+        {ok, Column} ->
+            case bind_arg(Statement, Column, Value) of
+                ok ->
+                    bind2(Statement, Args);
+                {error, _}=Error ->
+                    Error
+            end;
+        error ->
+            {error, named_parameter_not_found}
+    end.
+
 % Bind with automatic tyoe conversion
 bind_arg(Statement, Column, undefined) ->
     bind_null(Statement, Column);

src/esqlite3_nif.erl

@@ -42,6 +42,7 @@
     bind_text/3,
     bind_blob/3,
     bind_null/2,
+    bind_parameter_index/2,
 
     step/1,
 
@@ -194,6 +195,13 @@ bind_blob(_Statement, _Index, _Value) ->
 bind_null(_Statement, _Index) ->
     erlang:nif_error(nif_library_not_loaded).
 
+-spec bind_parameter_index(Statement, ParameterName) -> Result when
+      Statement :: esqlite3_stmt_ref(),
+      ParameterName :: iodata(),
+      Result :: {ok, integer()} | error.
+bind_parameter_index(_Statement, _ParameterName) ->
+    erlang:nif_error(nif_library_not_loaded).
+
 -spec step(Statement) -> StepResult when
       Statement :: esqlite3_stmt_ref(),
       StepResult :: row() | '$done' | error().