Promote Rex.Op.Missing to compile time error in strict (#1437)

Author: rchowell

partiql-eval/src/main/kotlin/org/partiql/eval/internal/Compiler.kt

@@ -26,6 +26,7 @@ import org.partiql.eval.internal.operator.rex.ExprCast
 import org.partiql.eval.internal.operator.rex.ExprCoalesce
 import org.partiql.eval.internal.operator.rex.ExprCollection
 import org.partiql.eval.internal.operator.rex.ExprLiteral
+import org.partiql.eval.internal.operator.rex.ExprMissing
 import org.partiql.eval.internal.operator.rex.ExprNullIf
 import org.partiql.eval.internal.operator.rex.ExprPathIndex
 import org.partiql.eval.internal.operator.rex.ExprPathKey
@@ -47,6 +48,7 @@ import org.partiql.plan.Rel
 import org.partiql.plan.Rex
 import org.partiql.plan.Statement
 import org.partiql.plan.debug.PlanPrinter
+import org.partiql.plan.rexOpErr
 import org.partiql.plan.visitor.PlanBaseVisitor
 import org.partiql.spi.fn.Agg
 import org.partiql.spi.fn.FnExperimental
@@ -233,6 +235,19 @@ internal class Compiler(
         return ExprCast(visitRex(node.arg, ctx), node.cast)
     }
 
+    override fun visitRexOpMissing(node: Rex.Op.Missing, ctx: StaticType?): Operator {
+        return when (session.mode) {
+            PartiQLEngine.Mode.PERMISSIVE -> {
+                // Make a runtime TypeCheckException.
+                ExprMissing(node.message)
+            }
+            PartiQLEngine.Mode.STRICT -> {
+                // Promote to error.
+                visitRexOpErr(rexOpErr(node.message, node.causes), null)
+            }
+        }
+    }
+
     // REL
     override fun visitRel(node: Rel, ctx: StaticType?): Operator.Relation {
         return super.visitRelOp(node.op, ctx) as Operator.Relation

partiql-eval/src/main/kotlin/org/partiql/eval/internal/operator/rex/ExprMissing.kt

@@ -0,0 +1,17 @@
+package org.partiql.eval.internal.operator.rex
+
+import org.partiql.errors.TypeCheckException
+import org.partiql.eval.internal.Environment
+import org.partiql.eval.internal.operator.Operator
+import org.partiql.value.PartiQLValue
+import org.partiql.value.PartiQLValueExperimental
+
+internal class ExprMissing(
+    private val message: String,
+) : Operator.Expr {
+
+    @OptIn(PartiQLValueExperimental::class)
+    override fun eval(env: Environment): PartiQLValue {
+        throw TypeCheckException(message)
+    }
+}