[groovy] 01/02: antlr4 based curly counting lexer

[pa...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

paulk pushed a commit to branch GROOVY_3_0_X
in repository https://gitbox.apache.org/repos/asf/groovy.git

commit 706402bd836ac24835bffbe33ea231c0e87e19a1
Author: Paul King <pa...@asert.com.au>
AuthorDate: Fri Sep 27 15:33:05 2019 +1000

    antlr4 based curly counting lexer
---
 .../util/antlr4/CurlyCountingGroovyLexer.groovy    | 77 ++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/subprojects/groovy-groovysh/src/main/groovy/org/apache/groovy/groovysh/util/antlr4/CurlyCountingGroovyLexer.groovy b/subprojects/groovy-groovysh/src/main/groovy/org/apache/groovy/groovysh/util/antlr4/CurlyCountingGroovyLexer.groovy
new file mode 100644
index 0000000..99fdfd2
--- /dev/null
+++ b/subprojects/groovy-groovysh/src/main/groovy/org/apache/groovy/groovysh/util/antlr4/CurlyCountingGroovyLexer.groovy
@@ -0,0 +1,77 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you under the Apache License, Version 2.0 (the
+ *  "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing,
+ *  software distributed under the License is distributed on an
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ */
+package org.apache.groovy.groovysh.util.antlr4
+
+import groovy.transform.CompileStatic
+import org.antlr.v4.runtime.CharStreams
+import org.antlr.v4.runtime.CommonTokenStream
+import org.antlr.v4.runtime.Token
+import org.apache.groovy.parser.antlr4.GroovyLangLexer
+
+/**
+ * patching GroovyLangLexer to get access to Paren level
+ */
+@CompileStatic
+class CurlyCountingGroovyLexer extends GroovyLangLexer {
+
+    protected CurlyCountingGroovyLexer(Reader reader) {
+        super(CharStreams.fromReader(reader))
+    }
+
+    static CurlyCountingGroovyLexer createGroovyLexer(String src) {
+        new CurlyCountingGroovyLexer(new StringReader(src))
+    }
+
+    private int curlyLevel
+    private List<Token> tokens = null
+
+    int getCurlyLevel() {
+        return curlyLevel
+    }
+
+    int countCurlyLevel() {
+        CommonTokenStream tokenStream = new CommonTokenStream(this)
+        try {
+            tokenStream.fill()
+            tokens = tokenStream.tokens
+        } catch (ignore) {
+        }
+
+        return curlyLevel
+    }
+
+    List<Token> toList() {
+        if (tokens == null) countCurlyLevel()
+        tokens
+    }
+
+    @Override
+    protected void enterParenCallback(String text) {
+        if ("{" == text) {
+            curlyLevel++
+        }
+    }
+
+    @Override
+    protected void exitParenCallback(String text) {
+        if ("}" == text) {
+            curlyLevel--
+        }
+    }
+}