Improved Json API

prange · May 8, 2019 · ba21b66 · ba21b66
1 parent ab53cdd
commit ba21b66
Show file tree

Hide file tree

Showing 3 changed files with 38 additions and 19 deletions.
diff --git a/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonDecoder.kt b/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonDecoder.kt
@@ -3,6 +3,7 @@ package org.kantega.niagara.json
 
 import java.math.BigDecimal
 import io.vavr.collection.List
+import org.kantega.niagara.data.curried
 
 typealias JsonDecoder<A> = (JsonValue) -> JsonResult<A>
 
@@ -21,6 +22,19 @@ infix fun <A, B> JsonDecoder<(A) -> B>.apply(v: JsonDecoder<A>): JsonDecoder<B>
 fun <A, B> decode(constructor: (A) -> B): JsonDecoder<(A) -> B> =
   { _ -> jOk(constructor) }
 
+fun <A, B, C> decode(constructor: (A, B) -> C): JsonDecoder<(A) -> (B) -> C> =
+  decode(constructor.curried())
+
+fun <A, B, C, D> decode(constructor: (A, B, C) -> D): JsonDecoder<(A) -> (B) -> (C) -> D> =
+  decode(constructor.curried())
+
+fun <A, B, C, D, E> decode(constructor: (A, B, C, D) -> E): JsonDecoder<(A) -> (B) -> (C) -> (D) -> E> =
+  decode(constructor.curried())
+
+fun <A, B, C, D, E, F> decode(constructor: (A, B, C, D, E) -> F): JsonDecoder<(A) -> (B) -> (C) -> (D) -> (E) -> F> =
+  decode(constructor.curried())
+
+
 val decodeString: JsonDecoder<String> =
   { it.asString() }
 
@@ -45,14 +59,14 @@ fun <A> decodeField(name: String, valueDecoder: JsonDecoder<A>): JsonDecoder<A>
 fun <A, B> JsonDecoder<(A) -> B>.field(name: String, decoderForField: JsonDecoder<A>): JsonDecoder<B> =
   this.apply(decodeField(name, decoderForField))
 
-fun <A, B> JsonDecoder<(A) -> B>.value(a:A): JsonDecoder<B> =
-  this.apply({ jOk(a)})
+fun <A, B> JsonDecoder<(A) -> B>.value(a: A): JsonDecoder<B> =
+  this.apply({ jOk(a) })
 
 fun <A> decodeArray(elemDecoder: JsonDecoder<A>): JsonDecoder<List<A>> =
   { it.asArray().bind { list -> list.a.map(elemDecoder).traverseJsonResult() } }
 
 fun <A> List<JsonResult<A>>.traverseJsonResult(): JsonResult<List<A>> =
-  this.foldRight(jOk(List.empty()),{ ja, jas -> jas.bind { alist -> ja.map { a -> alist.prepend(a) } } })
+  this.foldRight(jOk(List.empty()), { ja, jas -> jas.bind { alist -> ja.map { a -> alist.prepend(a) } } })
 
-fun <A> JsonDecoder<A>.or(other:JsonDecoder<A>):JsonDecoder<A> =
-  {jsonValue -> this(jsonValue).orElse({other(jsonValue)}) }
+fun <A> JsonDecoder<A>.or(other: JsonDecoder<A>): JsonDecoder<A> =
+  { jsonValue -> this(jsonValue).orElse({ other(jsonValue) }) }
diff --git a/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonResult.kt b/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonResult.kt
@@ -6,7 +6,7 @@ import org.kantega.niagara.data.NonEmptyList
 sealed class JsonResult<out A> {
 
 
-    abstract fun <T> fold(onFail: (NonEmptyList<String>) -> T, onSuccess: (A) -> T) : T
+    abstract fun <T> fold(onFail: (NonEmptyList<String>) -> T, onSuccess: (A) -> T): T
 
     fun <B> bind(f: (A) -> JsonResult<B>): JsonResult<B> =
       fold({ nel -> JsonResult.fail(nel) }, { a -> f(a) })
@@ -21,16 +21,16 @@ sealed class JsonResult<out A> {
       })
 
     override fun toString(): String {
-        return fold({ f -> "JsonResult(${f.toList().joinToString { it }})" }, { s -> "JsonResult("+s.toString()+")" })
+        return fold({ f -> "JsonResult(${f.toList().joinToString { it }})" }, { s -> "JsonResult(" + s.toString() + ")" })
     }
 
     companion object {
 
-        fun <A> fail(t: Throwable):JsonResult<A> =
+        fun <A> fail(t: Throwable): JsonResult<A> =
           JsonResult.fail(t.javaClass.simpleName + ":" + t.message.orEmpty())
 
-        fun <A> fail(msg: String,vararg tail:String):JsonResult<A> =
-          JsonResult.fail(NonEmptyList.of(msg,*tail))
+        fun <A> fail(msg: String, vararg tail: String): JsonResult<A> =
+          JsonResult.fail(NonEmptyList.of(msg, *tail))
 
         fun <A> fail(nel: NonEmptyList<String>) =
           JsonFail<A>(nel)
@@ -40,13 +40,13 @@ sealed class JsonResult<out A> {
     }
 }
 
-data class JsonSuccess<A>(val a:A):JsonResult<A>(){
+data class JsonSuccess<A>(val a: A) : JsonResult<A>() {
     override fun <T> fold(onFail: (NonEmptyList<String>) -> T, onSuccess: (A) -> T) =
       onSuccess(a)
 
 }
 
-data class JsonFail<A>(val failNel:NonEmptyList<String>):JsonResult<A>(){
+data class JsonFail<A>(val failNel: NonEmptyList<String>) : JsonResult<A>() {
     override fun <T> fold(onFail: (NonEmptyList<String>) -> T, onSuccess: (A) -> T): T =
       onFail(failNel)
 
@@ -55,10 +55,10 @@ data class JsonFail<A>(val failNel:NonEmptyList<String>):JsonResult<A>(){
 infix fun <A, B> JsonResult<(A) -> B>.apply(v: JsonResult<A>): JsonResult<B> =
   when {
       this is JsonSuccess && v is JsonSuccess -> jOk(this.a(v.a))
-      this is JsonFail && v is JsonFail -> JsonResult.fail(this.failNel + v.failNel)
-      this is JsonFail -> JsonResult.fail(this.failNel)
-      v is JsonFail -> JsonResult.fail(v.failNel)
-      else -> throw Error("unreachable code")
+      this is JsonFail && v is JsonFail       -> JsonResult.fail(this.failNel + v.failNel)
+      this is JsonFail                        -> JsonResult.fail(this.failNel)
+      v is JsonFail                           -> JsonResult.fail(v.failNel)
+      else                                    -> throw Error("unreachable code")
   }
 
 fun <A> JsonResult<JsonValue>.decode(decoder: JsonDecoder<A>): JsonResult<A> =
@@ -76,12 +76,17 @@ fun <A, B> jLift(f: (A) -> B) =
 infix fun <A> JsonResult<A>.orElse(a: A): A =
   this.fold({ a }, { c -> c })
 
+infix fun <A> JsonResult<A>.orElse(f: (NonEmptyList<String>) -> A): A =
+  this.fold({ f(it) }, { c -> c })
+
 infix fun <A> JsonResult<A>.orElse(a: JsonResult<A>): JsonResult<A> =
-  this.fold({ a }, {  this })
+  this.fold({ a }, { this })
 
 infix fun <A> JsonResult<A>.orElse(f: () -> JsonResult<A>): JsonResult<A> =
-  this.fold({ f() }, {  this })
+  this.fold({ f() }, { this })
 
+infix fun <A> JsonResult<A>.orElse(f: (NonEmptyList<String>) -> JsonResult<A>): JsonResult<A> =
+  this.fold({ nel -> f(nel) }, { this })
 
 fun JsonResult<JsonValue>.field(path: String): JsonResult<JsonValue> =
   this.field(JsonPath(path))

diff --git a/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonValues.kt b/niagara-json/src/main/kotlin/org/kantega/niagara/json/JsonValues.kt
@@ -45,7 +45,7 @@ interface JsonValue {
       asObject().bind { obj ->
           obj.m.get(name)
             .map { JsonResult.success(it) }
-            .getOrElse(JsonResult.fail("The field $name did not exist in the object"))
+            .getOrElse(JsonResult.fail("The field $name did not exist in the object. Available fields are {${obj.m.keySet().mkString(", ")}}"))
       }
 
 }