From 0fb5c7850dcf343b3b5929e9fe916125e771f916 Mon Sep 17 00:00:00 2001
From: dennis <killme2008@gmail.com>
Date: Fri, 22 Nov 2019 15:17:48 +0800
Subject: [PATCH] (fix) issue #177, parser bug

---
 .../aviator/code/OptimizeCodeGenerator.java   | 31 ++-----------------
 .../aviator/parser/ExpressionParser.java      | 31 ++++++++++++++++++-
 .../test/function/GrammarUnitTest.java        |  5 +++
 3 files changed, 38 insertions(+), 29 deletions(-)

diff --git a/src/main/java/com/googlecode/aviator/code/OptimizeCodeGenerator.java b/src/main/java/com/googlecode/aviator/code/OptimizeCodeGenerator.java
index 932c35fa..5f10bfd1 100644
--- a/src/main/java/com/googlecode/aviator/code/OptimizeCodeGenerator.java
+++ b/src/main/java/com/googlecode/aviator/code/OptimizeCodeGenerator.java
@@ -42,6 +42,7 @@
 import com.googlecode.aviator.lexer.token.Token.TokenType;
 import com.googlecode.aviator.lexer.token.Variable;
 import com.googlecode.aviator.parser.AviatorClassLoader;
+import com.googlecode.aviator.parser.ExpressionParser;
 import com.googlecode.aviator.parser.Parser;
 import com.googlecode.aviator.runtime.FunctionArgument;
 import com.googlecode.aviator.runtime.LambdaFunctionBootstrap;
@@ -236,32 +237,6 @@ private boolean isLiteralOperand(final Token<?> token, final TokenType tokenType
   }
 
 
-  private boolean isLiteralToken(final Token<?> token) {
-    switch (token.getType()) {
-      case Variable:
-        return token == Variable.TRUE || token == Variable.FALSE || token == Variable.NIL;
-      case Char:
-      case Number:
-      case Pattern:
-      case String:
-        return true;
-      default:
-        return false;
-    }
-  }
-
-  private boolean isConstant(final Token<?> token) {
-    switch (token.getType()) {
-      case Number:
-      case Pattern:
-      case String:
-        return true;
-      default:
-        return false;
-    }
-  }
-
-
   /**
    * Get token from executing result
    *
@@ -372,7 +347,7 @@ public Expression getResult() {
     Set<Token<?>> constants = new HashSet<>();
     for (Token<?> token : this.tokenList) {
 
-      if (isConstant(token)) {
+      if (ExpressionParser.isConstant(token)) {
         constants.add(token);
       }
 
@@ -424,7 +399,7 @@ public Expression getResult() {
         exp = new LiteralExpression(this.instance, null, new ArrayList<String>(variables.keySet()));
       } else {
         final Token<?> lastToken = this.tokenList.get(0);
-        if (isLiteralToken(lastToken)) {
+        if (ExpressionParser.isLiteralToken(lastToken)) {
           exp = new LiteralExpression(this.instance,
               getAviatorObjectFromToken(lastToken).getValue(null),
               new ArrayList<String>(variables.keySet()));
diff --git a/src/main/java/com/googlecode/aviator/parser/ExpressionParser.java b/src/main/java/com/googlecode/aviator/parser/ExpressionParser.java
index 7f0b2d88..aea904c8 100644
--- a/src/main/java/com/googlecode/aviator/parser/ExpressionParser.java
+++ b/src/main/java/com/googlecode/aviator/parser/ExpressionParser.java
@@ -457,8 +457,12 @@ public void unary() {
       factor();
     }
 
-    // FIXME: it's a parser bug here
+
     while (expectChar('[') || expectChar('(')) {
+      if (isConstant(this.prevToken)) {
+        break;
+      }
+
       if (expectChar('[')) {
         // (...)[index]
         arrayAccess();
@@ -893,4 +897,29 @@ private void ensureDepthState() {
     }
   }
 
+  public static boolean isConstant(final Token<?> token) {
+    switch (token.getType()) {
+      case Number:
+      case Pattern:
+      case String:
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  public static boolean isLiteralToken(final Token<?> token) {
+    switch (token.getType()) {
+      case Variable:
+        return token == Variable.TRUE || token == Variable.FALSE || token == Variable.NIL;
+      case Char:
+      case Number:
+      case Pattern:
+      case String:
+        return true;
+      default:
+        return false;
+    }
+  }
+
 }
diff --git a/src/test/java/com/googlecode/aviator/test/function/GrammarUnitTest.java b/src/test/java/com/googlecode/aviator/test/function/GrammarUnitTest.java
index e29c06dd..31b279f2 100644
--- a/src/test/java/com/googlecode/aviator/test/function/GrammarUnitTest.java
+++ b/src/test/java/com/googlecode/aviator/test/function/GrammarUnitTest.java
@@ -64,6 +64,11 @@ public void testIssue162() {
     assertEquals(new BigInteger("-2017122615550747128008704"), val);
   }
 
+  @Test(expected = ExpressionSyntaxErrorException.class)
+  public void testIssue177() {
+    AviatorEvaluator.compile("$age >30 ($age < 20)");
+  }
+
   @Test
   public void testIssue175() {
     Map<String, Object> env = new HashMap<>();