feat: support cast function date (#12738)

e2e_test/batch/functions/cast.slt.part

@@ -0,0 +1,40 @@
+statement ok
+create table dt (a date, b varchar);
+
+statement ok
+insert into dt values (date('2020-01-23'), '1990-12-19');
+
+query TT
+select
+    date(b)
+from
+dt
+except
+select
+    cast(b as date)
+from dt
+except
+select
+    b::date
+from dt;
+----
+
+statement ok
+drop table dt;
+
+query T
+select date('2030-03-30');
+----
+2030-03-30
+
+query error
+select date('2000-13-03');
+
+query error
+select date('00-00-33');
+
+query error cannot cast type "integer" to "date" in Explicit context
+select date(1);
+
+query error unexpected arguments number
+select date();

src/frontend/src/binder/expr/function.rs

@@ -1162,6 +1162,12 @@ impl Binder {
                 ("pg_sleep_for", raw_call(ExprType::PgSleepFor)),
                 // TODO: implement pg_sleep_until
                 // ("pg_sleep_until", raw_call(ExprType::PgSleepUntil)),
+
+                // cast functions
+                // only functions required by the existing PostgreSQL tool are implemented
+                ("date", guard_by_len(1, raw(|_binder, inputs| {
+                    inputs[0].clone().cast_explicit(DataType::Date).map_err(Into::into)
+                }))),
             ]
             .into_iter()
             .collect()