From b603c9f2c5a9005cd550d02c8d839a1ba421edfe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Przemys=C5=82aw=20Pluta?=
 <noreply.git@mx.bartlomiejpluta.com>
Date: Fri, 13 Mar 2020 10:04:55 +0100
Subject: [PATCH] Improve import parser and evaluator

---
 .../io/smnp/dsl/ast/model/node/ImportNode.kt  | 10 ++-----
 .../io/smnp/dsl/ast/parser/ImportParser.kt    | 30 ++++++++++++-------
 .../evaluation/evaluator/ImportEvaluator.kt   | 23 +-------------
 3 files changed, 23 insertions(+), 40 deletions(-)

diff --git a/app/src/main/kotlin/io/smnp/dsl/ast/model/node/ImportNode.kt b/app/src/main/kotlin/io/smnp/dsl/ast/model/node/ImportNode.kt
index 4862af0..cabad5d 100644
--- a/app/src/main/kotlin/io/smnp/dsl/ast/model/node/ImportNode.kt
+++ b/app/src/main/kotlin/io/smnp/dsl/ast/model/node/ImportNode.kt
@@ -2,11 +2,7 @@ package io.smnp.dsl.ast.model.node
 
 import io.smnp.dsl.token.model.entity.TokenPosition
 
-class ImportNode(path: Node, position: TokenPosition) : Node(1, position) {
-    val path: Node
-    get() = children[0]
-
-    init {
-        children[0] = path
-    }
+class ImportNode(path: List<Node>, position: TokenPosition) : Node(path, position) {
+    val path: List<Node>
+    get() = children
 }
\ No newline at end of file
diff --git a/app/src/main/kotlin/io/smnp/dsl/ast/parser/ImportParser.kt b/app/src/main/kotlin/io/smnp/dsl/ast/parser/ImportParser.kt
index e583cb0..3437f5b 100644
--- a/app/src/main/kotlin/io/smnp/dsl/ast/parser/ImportParser.kt
+++ b/app/src/main/kotlin/io/smnp/dsl/ast/parser/ImportParser.kt
@@ -2,21 +2,29 @@ package io.smnp.dsl.ast.parser
 
 import io.smnp.dsl.ast.model.entity.ParserOutput
 import io.smnp.dsl.ast.model.node.ImportNode
+import io.smnp.dsl.ast.model.node.Node
 import io.smnp.dsl.token.model.entity.TokenList
 import io.smnp.dsl.token.model.enumeration.TokenType
 
 class ImportParser : Parser() {
-    override fun tryToParse(input: TokenList): ParserOutput {
-        val pathParser = oneOf(
-            UnitParser(),
+   override fun tryToParse(input: TokenList): ParserOutput {
+      val pathParser = allOf(
+         SimpleIdentifierParser(),
+         optional(repeat(allOf(
+            terminal(TokenType.DOT),
             SimpleIdentifierParser()
-        )
+         ) { (_, child) -> child }) { segments, position ->
+            object : Node(segments, position) {}
+         })) { (firstSegment, otherSegments) ->
+         object : Node(listOf(firstSegment) + otherSegments.children, firstSegment.position) {}
+      }
 
-        return allOf(
-            terminal(TokenType.IMPORT),
-            pathParser
-        ) {
-            ImportNode(it[1], it[0].position)
-        }.parse(input)
-    }
+
+      return allOf(
+         terminal(TokenType.IMPORT),
+         pathParser
+      ) { (import, path) ->
+         ImportNode(path.children, import.position)
+      }.parse(input)
+   }
 }
\ No newline at end of file
diff --git a/app/src/main/kotlin/io/smnp/evaluation/evaluator/ImportEvaluator.kt b/app/src/main/kotlin/io/smnp/evaluation/evaluator/ImportEvaluator.kt
index a3758ab..cd9bda7 100644
--- a/app/src/main/kotlin/io/smnp/evaluation/evaluator/ImportEvaluator.kt
+++ b/app/src/main/kotlin/io/smnp/evaluation/evaluator/ImportEvaluator.kt
@@ -1,39 +1,18 @@
 package io.smnp.evaluation.evaluator
 
-import io.smnp.dsl.ast.model.node.AccessOperatorNode
 import io.smnp.dsl.ast.model.node.IdentifierNode
 import io.smnp.dsl.ast.model.node.ImportNode
 import io.smnp.dsl.ast.model.node.Node
 import io.smnp.environment.Environment
-import io.smnp.error.ShouldNeverReachThisLineException
 import io.smnp.evaluation.model.entity.EvaluatorOutput
 
 class ImportEvaluator : Evaluator() {
     override fun supportedNodes() = listOf(ImportNode::class)
 
     override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
-        val path = when (val pathNode = (node as ImportNode).path) {
-            is AccessOperatorNode -> complexPath(pathNode).joinToString(".")
-            is IdentifierNode -> pathNode.token.rawValue
-            else -> throw ShouldNeverReachThisLineException()
-        }
-
+        val path = (node as ImportNode).path.joinToString(".") { (it as IdentifierNode).token.rawValue }
         environment.loadModule(path)
 
         return EvaluatorOutput.ok()
     }
-
-    private fun complexPath(segment: AccessOperatorNode): List<String> {
-        val segments  = mutableListOf<String>()
-        val (lhs, _, rhs) = segment
-
-        segments.add((rhs as IdentifierNode).token.rawValue)
-
-        when(lhs) {
-            is AccessOperatorNode -> segments.addAll(complexPath(lhs))
-            is IdentifierNode -> segments.add(lhs.token.rawValue)
-        }
-
-        return segments.reversed()
-    }
 }
\ No newline at end of file