Merge 'Clean up functions' from Pekka Enberg

Move functions to a new `core/functions` module.

Closes #908

core/functions/datetime.rs

@@ -122,7 +122,7 @@ fn format_dt(dt: NaiveDateTime, output_type: DateTimeOutput, subsec: bool) -> St
 // Not as fast as if the formatting was native to chrono, but a good enough
 // for now, just to have the feature implemented
 fn strftime_format(dt: &NaiveDateTime, format_str: &str) -> String {
-    use super::strftime::CustomStrftimeItems;
+    use crate::functions::strftime::CustomStrftimeItems;
     use std::fmt::Write;
     // Necessary to remove %f and %J that are exclusive formatters to sqlite
     // Chrono does not support them, so it is necessary to replace the modifiers manually

core/functions/mod.rs

@@ -0,0 +1,3 @@
+pub mod datetime;
+pub mod printf;
+pub mod strftime;

core/lib.rs

@@ -1,6 +1,7 @@
 mod error;
 mod ext;
 mod function;
+mod functions;
 mod info;
 mod io;
 #[cfg(feature = "json")]

core/vdbe/mod.rs

@@ -18,17 +18,18 @@
 //! https://www.sqlite.org/opcode.html
 
 pub mod builder;
-mod datetime;
 pub mod explain;
 pub mod insn;
 pub mod likeop;
-mod printf;
 pub mod sorter;
-mod strftime;
 
 use crate::error::{LimboError, SQLITE_CONSTRAINT_PRIMARYKEY};
 use crate::ext::ExtValue;
 use crate::function::{AggFunc, ExtFunc, FuncCtx, MathFunc, MathFuncArity, ScalarFunc, VectorFunc};
+use crate::functions::datetime::{
+    exec_date, exec_datetime_full, exec_julianday, exec_strftime, exec_time, exec_unixepoch,
+};
+use crate::functions::printf::exec_printf;
 use crate::info;
 use crate::pseudo::PseudoCursor;
 use crate::result::LimboResult;
@@ -51,16 +52,12 @@ use crate::{
     json::json_remove, json::json_set, json::json_type,
 };
 use crate::{resolve_ext_path, Connection, Result, TransactionState, DATABASE_VERSION};
-use datetime::{
-    exec_date, exec_datetime_full, exec_julianday, exec_strftime, exec_time, exec_unixepoch,
-};
 use insn::{
     exec_add, exec_and, exec_bit_and, exec_bit_not, exec_bit_or, exec_boolean_not, exec_concat,
     exec_divide, exec_multiply, exec_or, exec_remainder, exec_shift_left, exec_shift_right,
     exec_subtract,
 };
 use likeop::{construct_like_escape_arg, exec_glob, exec_like_with_escape};
-use printf::exec_printf;
 use rand::distributions::{Distribution, Uniform};
 use rand::{thread_rng, Rng};
 use regex::{Regex, RegexBuilder};