Add lazy variants for {and,or,getOr,getErrorOr}

src/main/kotlin/com/github/michaelbull/result/And.kt

@@ -1,5 +1,10 @@
 package com.github.michaelbull.result
 
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("and { result }"))
+infix fun <V, E> Result<V, E>.and(result: Result<V, E>): Result<V, E> {
+    return and { result }
+}
+
 /**
  * Returns [result] if this [Result] is [Ok], otherwise this [Err].
  *
@@ -8,9 +13,9 @@ package com.github.michaelbull.result
  * @param result The [Result] to return if [Ok].
  * @return The [result] if [Ok], otherwise [Err].
  */
-infix fun <V, E> Result<V, E>.and(result: Result<V, E>): Result<V, E> {
+infix inline fun <V, E> Result<V, E>.and(result: () -> Result<V, E>): Result<V, E> {
     return when (this) {
-        is Ok -> result
+        is Ok -> result()
         is Err -> this
     }
 }

src/main/kotlin/com/github/michaelbull/result/Get.kt

@@ -29,6 +29,11 @@ fun <V, E> Result<V, E>.getError(): E? {
     }
 }
 
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("getOr { default }"))
+infix fun <V, E> Result<V, E>.getOr(default: V): V {
+    return getOr { default }
+}
+
 /**
  * Returns the [value][Ok.value] if this [Result] is [Ok], otherwise [default].
  *
@@ -39,13 +44,18 @@ fun <V, E> Result<V, E>.getError(): E? {
  * @param default The value to return if [Err].
  * @return The [value][Ok.value] if [Ok], otherwise [default].
  */
-infix fun <V, E> Result<V, E>.getOr(default: V): V {
+infix inline fun <V, E> Result<V, E>.getOr(default: () -> V): V {
     return when (this) {
         is Ok -> value
-        is Err -> default
+        is Err -> default()
     }
 }
 
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("getErrorOr { default }"))
+infix fun <V, E> Result<V, E>.getErrorOr(default: E): E {
+    return getErrorOr { default }
+}
+
 /**
  * Returns the [error][Err.error] if this [Result] is [Err], otherwise [default].
  *
@@ -54,9 +64,9 @@ infix fun <V, E> Result<V, E>.getOr(default: V): V {
  * @param default The error to return if [Ok].
  * @return The [error][Err.error] if [Err], otherwise [default].
  */
-infix fun <V, E> Result<V, E>.getErrorOr(default: E): E {
+infix inline fun <V, E> Result<V, E>.getErrorOr(default: () -> E): E {
     return when (this) {
-        is Ok -> default
+        is Ok -> default()
         is Err -> error
     }
 }

src/main/kotlin/com/github/michaelbull/result/Or.kt

@@ -1,5 +1,10 @@
 package com.github.michaelbull.result
 
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("or { result }"))
+infix fun <V, E> Result<V, E>.or(result: Result<V, E>): Result<V, E> {
+    return or { result }
+}
+
 /**
  * Returns [result] if this [Result] is [Err], otherwise this [Ok].
  *
@@ -8,10 +13,10 @@ package com.github.michaelbull.result
  * @param result The [Result] to return if [Err].
  * @return The [result] if [Err], otherwise [Ok].
  */
-infix fun <V, E> Result<V, E>.or(result: Result<V, E>): Result<V, E> {
+infix inline fun <V, E> Result<V, E>.or(result: () -> Result<V, E>): Result<V, E> {
     return when (this) {
         is Ok -> this
-        is Err -> result
+        is Err -> result()
     }
 }
 

src/main/kotlin/com/github/michaelbull/result/Unwrap.kt

@@ -16,7 +16,7 @@ fun <V, E> Result<V, E>.unwrap(): V {
     }
 }
 
-@Deprecated("Use lazy evaluation.", ReplaceWith("expect { message }"))
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("expect { message }"))
 infix fun <V, E> Result<V, E>.expect(message: String): V {
     return expect { message }
 }
@@ -50,7 +50,7 @@ fun <V, E> Result<V, E>.unwrapError(): E {
     }
 }
 
-@Deprecated("Use lazy evaluation.", ReplaceWith("expectError { message }"))
+@Deprecated("Use lazy-evaluating variant instead", ReplaceWith("expectError { message }"))
 infix fun <V, E> Result<V, E>.expectError(message: String): E {
     return expectError { message }
 }

src/test/kotlin/com/github/michaelbull/result/AndTest.kt

@@ -12,7 +12,7 @@ internal class AndTest {
         internal fun returnsValueIfOk() {
             assertEquals(
                 expected = 500,
-                actual = Ok(230).and(Ok(500)).get()
+                actual = Ok(230).and { Ok(500) }.get()
             )
         }
 
@@ -20,7 +20,7 @@ internal class AndTest {
         internal fun returnsValueIfErr() {
             assertEquals(
                 expected = "hello world",
-                actual = Ok(300).and(Err("hello world")).getError()
+                actual = Ok(300).and { Err("hello world") }.getError()
             )
         }
     }

src/test/kotlin/com/github/michaelbull/result/GetTest.kt

@@ -40,7 +40,7 @@ internal class GetTest {
         internal fun returnsValueIfOk() {
             assertEquals(
                 expected = "hello",
-                actual = Ok("hello").getOr("world")
+                actual = Ok("hello").getOr { "world" }
             )
         }
 
@@ -48,7 +48,7 @@ internal class GetTest {
         internal fun returnsDefaultValueIfErr() {
             assertEquals(
                 expected = "default",
-                actual = Err("error").getOr("default")
+                actual = Err("error").getOr { "default" }
             )
         }
     }
@@ -58,7 +58,7 @@ internal class GetTest {
         internal fun returnsDefaultValueIfOk() {
             assertEquals(
                 expected = "world",
-                actual = Ok("hello").getErrorOr("world")
+                actual = Ok("hello").getErrorOr { "world" }
             )
         }
 
@@ -66,7 +66,7 @@ internal class GetTest {
         internal fun returnsErrorIfErr() {
             assertEquals(
                 expected = "hello",
-                actual = Err("hello").getErrorOr("world")
+                actual = Err("hello").getErrorOr { "world" }
             )
         }
     }

src/test/kotlin/com/github/michaelbull/result/OrTest.kt

@@ -11,7 +11,7 @@ internal class OrTest {
         internal fun returnsValueIfOk() {
             assertEquals(
                 expected = 500,
-                actual = Ok(500).or(Ok(1000)).get()
+                actual = Ok(500).or { Ok(1000) }.get()
             )
         }
 
@@ -19,7 +19,7 @@ internal class OrTest {
         internal fun returnsDefaultValueIfErr() {
             assertEquals(
                 expected = 5000,
-                actual = Err(OrError).or(Ok(5000)).get()
+                actual = Err(OrError).or { Ok(5000) }.get()
             )
         }
     }