Re-parse after lambda was converted to block (KT-17156)

#KT-17156 Fixed
2017-03-30 19:45:48 +03:00
parent c740c0b177
commit 6201aa4fd9
2 changed files with 122 additions and 1 deletions
@@ -22,9 +22,12 @@ import com.intellij.lang.PsiBuilder;
 import com.intellij.lang.PsiBuilderFactory;
 import com.intellij.lexer.Lexer;
 import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiElement;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.IErrorCounterReparseableElementType;
 import com.intellij.psi.tree.IFileElementType;
+import com.intellij.psi.util.PsiTreeUtil;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.idea.KotlinLanguage;
 import org.jetbrains.kotlin.lexer.KotlinLexer;
 import org.jetbrains.kotlin.lexer.KtTokens;
@@ -130,7 +133,8 @@ public interface KtNodeTypes {
        @Override
        public ASTNode parseContents(ASTNode chameleon) {
            Project project = chameleon.getPsi().getProject();
-            PsiBuilder builder = PsiBuilderFactory.getInstance().createBuilder(project, chameleon, null, KotlinLanguage.INSTANCE, chameleon.getChars());
+            PsiBuilder builder = PsiBuilderFactory.getInstance().createBuilder(
+                    project, chameleon, null, KotlinLanguage.INSTANCE, chameleon.getChars());
            return KotlinParser.parseLambdaExpression(builder).getFirstChildNode();
        }

@@ -139,6 +143,66 @@ public interface KtNodeTypes {
            return new KtLambdaExpression(text);
        }

+        @Override
+        public boolean isParsable(@Nullable ASTNode parent, CharSequence buffer, Language fileLanguage, Project project) {
+            return super.isParsable(parent, buffer, fileLanguage, project) &&
+                   !wasArrowMovedOrDeleted(parent, buffer);
+        }
+
+        private boolean wasArrowMovedOrDeleted(@Nullable ASTNode parent, CharSequence buffer) {
+            if (parent == null) return false;
+
+            PsiElement parentPsi = parent.getPsi();
+            KtLambdaExpression[] lambdaExpressions = PsiTreeUtil.getChildrenOfType(parentPsi, KtLambdaExpression.class);
+            if (lambdaExpressions == null || lambdaExpressions.length != 1) return false;
+
+            // Now works only when actual node can be spotted ambiguously. Need change in API.
+            KtLambdaExpression lambdaExpression = lambdaExpressions[0];
+            KtFunctionLiteral literal = lambdaExpression.getFunctionLiteral();
+            PsiElement arrow = literal.getArrow();
+
+            // No arrow in original node
+            if (arrow == null) return false;
+
+            int arrowOffset = arrow.getStartOffsetInParent() + literal.getStartOffsetInParent();
+
+            Lexer oldLexer = new KotlinLexer();
+            oldLexer.start(lambdaExpression.getText());
+
+            Lexer newLexer = new KotlinLexer();
+            newLexer.start(buffer);
+
+            while (true) {
+                IElementType oldType = oldLexer.getTokenType();
+                if (oldType == null) break; // Didn't find an arrow token. Consider it as no arrow was present.
+
+                IElementType newType = newLexer.getTokenType();
+                if (newType == null) return true; // New text was finished before reaching arrow in old text
+
+                if (newType != oldType) {
+                    if (newType == KtTokens.WHITE_SPACE) {
+                        newLexer.advance();
+                        continue;
+                    }
+                    else if (oldType == KtTokens.WHITE_SPACE) {
+                        oldLexer.advance();
+                        continue;
+                    }
+
+                    return true; // Arrow was moved or deleted
+                }
+
+                if (oldType == KtTokens.ARROW && oldLexer.getCurrentPosition().getOffset() == arrowOffset) {
+                    break;
+                }
+
+                oldLexer.advance();
+                newLexer.advance();
+            }
+
+            return false;
+        }
+
        @Override
        public int getErrorsCount(CharSequence seq, Language fileLanguage, Project project) {
            Lexer lexer = new KotlinLexer();