From 2c6fb5a8e865290ade760c15001773af88c4078c Mon Sep 17 00:00:00 2001
From: Rob Norris <rob_norris@mac.com>
Date: Fri, 12 Aug 2022 09:55:22 -0500
Subject: [PATCH] convenience methods

---
 modules/core/src/main/scala/cursor.scala  |  8 ++++++++
 modules/core/src/main/scala/package.scala | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/modules/core/src/main/scala/cursor.scala b/modules/core/src/main/scala/cursor.scala
index cedda111..80f4e643 100644
--- a/modules/core/src/main/scala/cursor.scala
+++ b/modules/core/src/main/scala/cursor.scala
@@ -9,6 +9,7 @@ import scala.reflect.{classTag, ClassTag}
 import cats.data.Ior
 import cats.implicits._
 import io.circe.Json
+import org.tpolecat.typename.{ TypeName, typeName }
 
 import Cursor.{ cast, Context, Env }
 import QueryInterpreter.{ mkErrorResult, mkOneError }
@@ -305,6 +306,13 @@ object Cursor {
     def add[T](items: (String, T)*): Env
     def add(env: Env): Env
     def get[T: ClassTag](name: String): Option[T]
+
+    def getR[A: ClassTag: TypeName](name: String): Result[A] =
+      get[A](name) match {
+        case None        => Result.failure(s"Key '$name' of type ${typeName[A]} was not found in $this")
+        case Some(value) => Result(value)
+      }
+
   }
 
   object Env {
diff --git a/modules/core/src/main/scala/package.scala b/modules/core/src/main/scala/package.scala
index ca8369da..a38b9512 100644
--- a/modules/core/src/main/scala/package.scala
+++ b/modules/core/src/main/scala/package.scala
@@ -6,6 +6,7 @@ package edu.gemini
 import cats.data.IorNec
 import cats.data.Ior
 import cats.data.NonEmptyChain
+import cats.syntax.all._
 
 package object grackle {
   /**
@@ -29,6 +30,27 @@ package object grackle {
     def failure[A](p: Problem): Result[A] =
       Ior.left(NonEmptyChain(p))
 
+    def fromOption[A](oa: Option[A], ifNone: => Problem): Result[A] =
+      oa match {
+        case Some(a) => Result(a)
+        case None    => Result.failure(ifNone)
+      }
+
+    def fromEither[A](ea: Either[Problem, A]): Result[A] =
+      ea.fold(Result.failure(_), Result.apply)
+
+    def warning[A](warning: Problem, value: A): Result[A] =
+      Result.failure[A](warning).putRight(value)
+
+    def fromOption[A](oa: Option[A], ifNone: => String)(implicit ev: DummyImplicit): Result[A] =
+      fromOption(oa, Problem(ifNone))
+
+    def fromEither[A](ea: Either[String, A])(implicit ev: DummyImplicit): Result[A] =
+      fromEither(ea.leftMap(Problem(_)))
+
+    def warning[A](warning: String, value: A): Result[A] =
+      this.warning(Problem(warning), value)
+
   }
 
 }