Use String instead of ExactError

README.md

@@ -10,17 +10,17 @@ Exact allows automatically projecting smart-constructors on a `Companion Object`
 example easily create a `NotBlankString` type that is a `String` that is not blank, leveraging
 the Arrow's `Raise` DSL to `ensure` the value is not blank.
 
-```kotlin
+<!--- INCLUDE
 import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
-
+-->
+```kotlin
 @JvmInline
 value class NotBlankString private constructor(val value: String) { 
   companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString { 
+    override fun Raise<String>.spec(raw: String): NotBlankString { 
       ensure(raw.isNotBlank())
       return NotBlankString(raw)
     }
@@ -45,12 +45,46 @@ The output of the above program is:
 
 ```text
 Either.Right(NotBlankString(value=Hello))
-Either.Left(ExactError(message=Failed condition.))
+Either.Left(Failed condition.)
 ```
 
 <!--- KNIT example-readme-01.kt -->
 <!--- TEST -->
 
+By default, if no error message is provided it'll use `Failed condition.`,
+but just like `require` from the Kotlin Standard Library you can provide your own error message.
+
+<!--- INCLUDE
+import arrow.core.raise.Raise
+import arrow.exact.Exact
+import arrow.core.raise.ensure
+import kotlin.jvm.JvmInline
+-->
+```kotlin
+@JvmInline
+value class NotBlankString private constructor(val value: String) { 
+  companion object : Exact<String, NotBlankString> {
+    override fun Raise<String>.spec(raw: String): NotBlankString { 
+      ensure(raw.isNotBlank()) { "String must not be blank." }
+      return NotBlankString(raw)
+    }
+  }
+}
+
+fun example() {
+  println(NotBlankString.from(""))
+}
+```
+
+The output of the above program is:
+
+```text
+Either.Left(String must not be blank.)
+```
+
+<!--- KNIT example-readme-02.kt -->
+<!--- TEST -->
+
 You can also define `Exact` by using Kotlin delegation.
 <!--- INCLUDE
 import arrow.exact.Exact
@@ -66,22 +100,21 @@ value class NotBlankString private constructor(val value: String) {
    })
 }
 ```
-<!--- KNIT example-readme-02.kt -->
+<!--- KNIT example-readme-03.kt -->
 
 You can define a second type `NotBlankTrimmedString` that is a `NotBlankString` that is also
 trimmed. `ensureExact` allows us to compose `Exact` instances and easily
 reuse the `NotBlankString` type.
 <!--- INCLUDE
 import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
 value class NotBlankString private constructor(val value: String) {
   companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString {
+    override fun Raise<String>.spec(raw: String): NotBlankString {
       ensure(raw.isNotBlank())
       return NotBlankString(raw)
     }
@@ -93,12 +126,12 @@ value class NotBlankString private constructor(val value: String) {
 @JvmInline
 value class NotBlankTrimmedString private constructor(val value: String) { 
   companion object : Exact<String, NotBlankTrimmedString> { 
-    override fun Raise<ExactError>.spec(raw: String): NotBlankTrimmedString { 
+    override fun Raise<String>.spec(raw: String): NotBlankTrimmedString { 
       ensure(raw, NotBlankString)
       return NotBlankTrimmedString(raw.trim())
     }
   }
 }
 ```
 
-<!--- KNIT example-readme-03.kt -->
+<!--- KNIT example-readme-04.kt -->

guide/src/commonMain/kotlin/examples/example-exact-01.kt

@@ -3,14 +3,13 @@ package arrow.exact.knit.example.exampleExact01
 
 import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
 value class NotBlankString private constructor(val value: String) {
   companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString {
+    override fun Raise<String>.spec(raw: String): NotBlankString {
       ensure(raw.isNotBlank())
       return NotBlankString(raw)
     }

guide/src/commonMain/kotlin/examples/example-exact-02.kt

@@ -1,14 +1,21 @@
 // This file was automatically generated from Exact.kt by Knit tool. Do not edit.
 package arrow.exact.knit.example.exampleExact02
 
+import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ensure
+import arrow.core.raise.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
 value class NotBlankString private constructor(val value: String) {
-  companion object : Exact<String, NotBlankString> by Exact({
-    ensure(it.isNotBlank())
-    NotBlankString(it)
-  })
+  companion object : Exact<String, NotBlankString> {
+    override fun Raise<String>.spec(raw: String): NotBlankString {
+      ensure(raw.isNotBlank()) { "String must not be blank." }
+      return NotBlankString(raw)
+    }
+  }
+}
+
+fun example() {
+  println(NotBlankString.from(""))
 }

guide/src/commonMain/kotlin/examples/example-exact-03.kt

@@ -1,27 +1,14 @@
 // This file was automatically generated from Exact.kt by Knit tool. Do not edit.
 package arrow.exact.knit.example.exampleExact03
 
-import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
-class NotBlankString private constructor(val value: String) {
-  companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString {
-      ensure(raw.isNotBlank())
-      return NotBlankString(raw)
-    }
-  }
-}
-
 @JvmInline
-value class NotBlankTrimmedString private constructor(val value: String) {
-  companion object : Exact<String, NotBlankTrimmedString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankTrimmedString {
-      ensure(raw, NotBlankString)
-      return NotBlankTrimmedString(raw.trim())
-    }
-  }
+value class NotBlankString private constructor(val value: String) {
+  companion object : Exact<String, NotBlankString> by Exact({
+    ensure(it.isNotBlank())
+    NotBlankString(it)
+  })
 }

guide/src/commonMain/kotlin/examples/example-exact-04.kt

@@ -2,39 +2,25 @@
 package arrow.exact.knit.example.exampleExact04
 
 import arrow.core.raise.Raise
-import arrow.core.raise.ensure
 import arrow.exact.Exact
-import arrow.exact.ExactEither
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
-@JvmInline
-value class NotBlankTrimmedString private constructor(val value: String) {
-  companion object : Exact<String, NotBlankTrimmedString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankTrimmedString {
+class NotBlankString private constructor(val value: String) {
+  companion object : Exact<String, NotBlankString> {
+    override fun Raise<String>.spec(raw: String): NotBlankString {
       ensure(raw.isNotBlank())
-      return NotBlankTrimmedString(raw.trim())
+      return NotBlankString(raw)
     }
   }
 }
 
-sealed interface UsernameError {
-  object Invalid : UsernameError
-  data class Offensive(val username: String) : UsernameError
-}
-
 @JvmInline
-value class Username private constructor(val value: String) {
-  companion object : ExactEither<UsernameError, String, Username> {
-    override fun Raise<UsernameError>.spec(raw: String): Username {
-      val username =
-        ensure(raw, NotBlankTrimmedString) {
-          UsernameError.Invalid
-        }.value
-      ensure(username.length < 100) { UsernameError.Invalid }
-      ensure(username !in listOf("offensive")) { UsernameError.Offensive(username) }
-      return Username(username)
+value class NotBlankTrimmedString private constructor(val value: String) {
+  companion object : Exact<String, NotBlankTrimmedString> {
+    override fun Raise<String>.spec(raw: String): NotBlankTrimmedString {
+      ensure(raw, NotBlankString)
+      return NotBlankTrimmedString(raw.trim())
     }
   }
 }

guide/src/commonMain/kotlin/examples/example-exact-05.kt

@@ -0,0 +1,39 @@
+// This file was automatically generated from Exact.kt by Knit tool. Do not edit.
+package arrow.exact.knit.example.exampleExact05
+
+import arrow.core.raise.Raise
+import arrow.core.raise.ensure
+import arrow.exact.Exact
+import arrow.exact.ExactEither
+import arrow.exact.ensure
+import kotlin.jvm.JvmInline
+
+@JvmInline
+value class NotBlankTrimmedString private constructor(val value: String) {
+  companion object : Exact<String, NotBlankTrimmedString> {
+    override fun Raise<String>.spec(raw: String): NotBlankTrimmedString {
+      ensure(raw.isNotBlank())
+      return NotBlankTrimmedString(raw.trim())
+    }
+  }
+}
+
+sealed interface UsernameError {
+  object Invalid : UsernameError
+  data class Offensive(val username: String) : UsernameError
+}
+
+@JvmInline
+value class Username private constructor(val value: String) {
+  companion object : ExactEither<UsernameError, String, Username> {
+    override fun Raise<UsernameError>.spec(raw: String): Username {
+      val username =
+        ensure(raw, NotBlankTrimmedString) {
+          UsernameError.Invalid
+        }.value
+      ensure(username.length < 100) { UsernameError.Invalid }
+      ensure(username !in listOf("offensive")) { UsernameError.Offensive(username) }
+      return Username(username)
+    }
+  }
+}

guide/src/commonMain/kotlin/examples/example-readme-01.kt

@@ -3,14 +3,13 @@ package arrow.exact.knit.example.exampleReadme01
 
 import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
 value class NotBlankString private constructor(val value: String) { 
   companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString { 
+    override fun Raise<String>.spec(raw: String): NotBlankString { 
       ensure(raw.isNotBlank())
       return NotBlankString(raw)
     }

guide/src/commonMain/kotlin/examples/example-readme-02.kt

@@ -1,14 +1,21 @@
 // This file was automatically generated from README.md by Knit tool. Do not edit.
 package arrow.exact.knit.example.exampleReadme02
 
+import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ensure
+import arrow.core.raise.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
-value class NotBlankString private constructor(val value: String) {
-   companion object : Exact<String, NotBlankString> by Exact({
-     ensure(it.isNotBlank())
-     NotBlankString(it)
-   })
+value class NotBlankString private constructor(val value: String) { 
+  companion object : Exact<String, NotBlankString> {
+    override fun Raise<String>.spec(raw: String): NotBlankString { 
+      ensure(raw.isNotBlank()) { "String must not be blank." }
+      return NotBlankString(raw)
+    }
+  }
+}
+
+fun example() {
+  println(NotBlankString.from(""))
 }

guide/src/commonMain/kotlin/examples/example-readme-03.kt

@@ -1,28 +1,14 @@
 // This file was automatically generated from README.md by Knit tool. Do not edit.
 package arrow.exact.knit.example.exampleReadme03
 
-import arrow.core.raise.Raise
 import arrow.exact.Exact
-import arrow.exact.ExactError
 import arrow.exact.ensure
 import kotlin.jvm.JvmInline
 
 @JvmInline
 value class NotBlankString private constructor(val value: String) {
-  companion object : Exact<String, NotBlankString> {
-    override fun Raise<ExactError>.spec(raw: String): NotBlankString {
-      ensure(raw.isNotBlank())
-      return NotBlankString(raw)
-    }
-  }
-}
-
-@JvmInline
-value class NotBlankTrimmedString private constructor(val value: String) { 
-  companion object : Exact<String, NotBlankTrimmedString> { 
-    override fun Raise<ExactError>.spec(raw: String): NotBlankTrimmedString { 
-      ensure(raw, NotBlankString)
-      return NotBlankTrimmedString(raw.trim())
-    }
-  }
+   companion object : Exact<String, NotBlankString> by Exact({
+     ensure(it.isNotBlank())
+     NotBlankString(it)
+   })
 }

guide/src/commonMain/kotlin/examples/example-readme-04.kt

@@ -0,0 +1,27 @@
+// This file was automatically generated from README.md by Knit tool. Do not edit.
+package arrow.exact.knit.example.exampleReadme04
+
+import arrow.core.raise.Raise
+import arrow.exact.Exact
+import arrow.exact.ensure
+import kotlin.jvm.JvmInline
+
+@JvmInline
+value class NotBlankString private constructor(val value: String) {
+  companion object : Exact<String, NotBlankString> {
+    override fun Raise<String>.spec(raw: String): NotBlankString {
+      ensure(raw.isNotBlank())
+      return NotBlankString(raw)
+    }
+  }
+}
+
+@JvmInline
+value class NotBlankTrimmedString private constructor(val value: String) { 
+  companion object : Exact<String, NotBlankTrimmedString> { 
+    override fun Raise<String>.spec(raw: String): NotBlankTrimmedString { 
+      ensure(raw, NotBlankString)
+      return NotBlankTrimmedString(raw.trim())
+    }
+  }
+}

guide/src/jvmTest/kotlin/examples/spec/ExactExampleSpec.kt

@@ -10,7 +10,14 @@ class ExactExampleSpec : StringSpec({
     captureOutput("ExampleExact01") { arrow.exact.knit.example.exampleExact01.example() }
       .verifyOutputLines(
         "Either.Right(NotBlankString(value=Hello))",
-        "Either.Left(ExactError(message=Failed condition.))"
+        "Either.Left(Failed condition.)"
+      )
+  }
+
+  "ExampleExact02" {
+    captureOutput("ExampleExact02") { arrow.exact.knit.example.exampleExact02.example() }
+      .verifyOutputLines(
+        "Either.Left(String must not be blank.)"
       )
   }