Support isnull and notnull expr

core/translate/expr.rs

@@ -1949,7 +1949,25 @@ pub fn translate_expr(
         ast::Expr::InList { .. } => todo!(),
         ast::Expr::InSelect { .. } => todo!(),
         ast::Expr::InTable { .. } => todo!(),
-        ast::Expr::IsNull(_) => todo!(),
+        ast::Expr::IsNull(expr) => {
+            let reg = program.alloc_register();
+            translate_expr(program, referenced_tables, expr, reg, resolver)?;
+            program.emit_insn(Insn::Integer {
+                value: 1,
+                dest: target_register,
+            });
+            let label = program.allocate_label();
+            program.emit_insn(Insn::IsNull {
+                reg,
+                target_pc: label,
+            });
+            program.emit_insn(Insn::Integer {
+                value: 0,
+                dest: target_register,
+            });
+            program.preassign_label_to_next_insn(label);
+            Ok(target_register)
+        }
         ast::Expr::Like { not, .. } => {
             let like_reg = if *not {
                 program.alloc_register()
@@ -2039,7 +2057,25 @@ pub fn translate_expr(
             }
         },
         ast::Expr::Name(_) => todo!(),
-        ast::Expr::NotNull(_) => todo!(),
+        ast::Expr::NotNull(expr) => {
+            let reg = program.alloc_register();
+            translate_expr(program, referenced_tables, expr, reg, resolver)?;
+            program.emit_insn(Insn::Integer {
+                value: 1,
+                dest: target_register,
+            });
+            let label = program.allocate_label();
+            program.emit_insn(Insn::NotNull {
+                reg,
+                target_pc: label,
+            });
+            program.emit_insn(Insn::Integer {
+                value: 0,
+                dest: target_register,
+            });
+            program.preassign_label_to_next_insn(label);
+            Ok(target_register)
+        }
         ast::Expr::Parenthesized(exprs) => {
             if exprs.is_empty() {
                 crate::bail_parse_error!("parenthesized expression with no arguments");

testing/all.test

@@ -32,3 +32,4 @@ source $testdir/drop_index.test
 source $testdir/default_value.test
 source $testdir/boolean.test
 source $testdir/literal.test
+source $testdir/null.test

testing/null.test

@@ -0,0 +1,20 @@
+#!/usr/bin/env tclsh
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_execsql_test isnull {
+    select null isnull, 'hi' isnull;
+} {1|0}
+
+do_execsql_test is-null {
+    select null is null, 'hi' is null;
+} {1|0}
+
+do_execsql_test notnull {
+    select null notnull, 'hi' notnull;
+} {0|1}
+
+do_execsql_test not-null {
+    select null not null, 'hi' not null;
+} {0|1}