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Posted to notifications@freemarker.apache.org by dd...@apache.org on 2020/10/13 19:57:41 UTC

[freemarker] 02/02: Forward ported from 2.3-gae: Added ?eval_json to evaluate JSON given as flat string. This was added as ?eval is routinely misused for the same purpose.

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

ddekany pushed a commit to branch 3
in repository https://gitbox.apache.org/repos/asf/freemarker.git

commit 18cfeb4aa85916d80d961b7c2fe15b1cb3bcaf00
Author: ddekany <dd...@apache.org>
AuthorDate: Tue Oct 13 21:56:31 2020 +0200

    Forward ported from 2.3-gae: Added ?eval_json to evaluate JSON given as flat string. This was added as ?eval is routinely misused for the same purpose.
---
 .../freemarker/core/EvalJsonBuiltInTest.java       |  36 ++
 .../org/apache/freemarker/core/JSONParserTest.java | 170 ++++++
 .../org/apache/freemarker/core/ASTExpBuiltIn.java  |   4 +-
 .../freemarker/core/BuiltInsForStringsMisc.java    |  38 +-
 .../org/apache/freemarker/core/JSONParser.java     | 616 +++++++++++++++++++++
 5 files changed, 852 insertions(+), 12 deletions(-)

diff --git a/freemarker-core-test/src/test/java/org/apache/freemarker/core/EvalJsonBuiltInTest.java b/freemarker-core-test/src/test/java/org/apache/freemarker/core/EvalJsonBuiltInTest.java
new file mode 100644
index 0000000..0c733be
--- /dev/null
+++ b/freemarker-core-test/src/test/java/org/apache/freemarker/core/EvalJsonBuiltInTest.java
@@ -0,0 +1,36 @@
+/*
+ * 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.freemarker.core;
+
+import org.apache.freemarker.test.TemplateTest;
+import org.junit.Test;
+
+public class EvalJsonBuiltInTest extends TemplateTest {
+
+    @Test
+    public void test() throws Exception {
+        assertOutput("${'1'?evalJson}", "1");
+
+        assertOutput("${'null'?evalJson!'-'}", "-");
+
+        assertOutput("<#list '{\"a\": 1e2, \"b\": null}'?evalJson as k, v>${k}=${v!'NULL'}<#sep>, </#list>", "a=100, b=NULL");
+    }
+
+}
diff --git a/freemarker-core-test/src/test/java/org/apache/freemarker/core/JSONParserTest.java b/freemarker-core-test/src/test/java/org/apache/freemarker/core/JSONParserTest.java
new file mode 100644
index 0000000..4336d2b
--- /dev/null
+++ b/freemarker-core-test/src/test/java/org/apache/freemarker/core/JSONParserTest.java
@@ -0,0 +1,170 @@
+/*
+ * 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.freemarker.core;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+import java.math.BigDecimal;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+
+import org.apache.freemarker.core.model.TemplateModel;
+import org.apache.freemarker.core.util.BugException;
+import org.apache.freemarker.core.util.DeepUnwrap;
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+
+public class JSONParserTest {
+
+    @Test
+    public void testObjects() throws JSONParser.JSONParseException {
+        assertEquals(ImmutableMap.of("a", 1, "b", 2), JSONParser.parse("{\"a\": 1, \"b\": 2}"));
+        assertEquals(Collections.emptyMap(), JSONParser.parse("{}"));
+        try {
+            JSONParser.parse("{1: 1}");
+            fail();
+        } catch (JSONParser.JSONParseException e) {
+            assertThat(e.getMessage(), containsString("string key"));
+        }
+    }
+
+    @Test
+    public void testLists() throws JSONParser.JSONParseException {
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("[1, 2]"));
+        assertEquals(Collections.emptyList(), JSONParser.parse("[]"));
+    }
+
+    @Test
+    public void testStrings() throws JSONParser.JSONParseException {
+        assertEquals("", JSONParser.parse("\"\""));
+        assertEquals(" ", JSONParser.parse("\" \""));
+        assertEquals("'", JSONParser.parse("\"'\""));
+        assertEquals("foo", JSONParser.parse("\"foo\""));
+        assertEquals("\" \\ / \b \f \n \r \t \ufeff",
+                JSONParser.parse(
+                        "\"" +
+                                "\\\" \\\\ \\/ \\b \\f \\n \\r \\t \\uFEFF" +
+                                "\""));
+    }
+
+    @Test
+    public void testNumbers() throws JSONParser.JSONParseException {
+        assertEquals(0, JSONParser.parse("0"));
+        assertEquals(123, JSONParser.parse("123"));
+        assertEquals(-123, JSONParser.parse("-123"));
+        assertNotEquals(123L, JSONParser.parse("123"));
+        assertEquals(2147483647, JSONParser.parse("2147483647"));
+        assertEquals(2147483648L, JSONParser.parse("2147483648"));
+        assertEquals(-2147483648, JSONParser.parse("-2147483648"));
+        assertEquals(-2147483649L, JSONParser.parse("-2147483649"));
+        assertEquals(-123, JSONParser.parse("-1.23E2"));
+        assertEquals(new BigDecimal("1.23"), JSONParser.parse("1.23"));
+        assertEquals(new BigDecimal("-1.23"), JSONParser.parse("-1.23"));
+        assertEquals(new BigDecimal("12.3"), JSONParser.parse("1.23E1"));
+        assertEquals(new BigDecimal("0.123"), JSONParser.parse("123E-3"));
+    }
+
+    @Test
+    public void testKeywords() throws JSONParser.JSONParseException {
+        assertEquals(null, JSONParser.parse("null"));
+        assertEquals(true, JSONParser.parse("true"));
+        assertEquals(false, JSONParser.parse("false"));
+        try {
+            JSONParser.parse("NULL");
+            fail();
+        } catch (JSONParser.JSONParseException e) {
+            assertThat(e.getMessage(), containsString("quoted"));
+        }
+    }
+
+    @Test
+    public void testBlockComments() throws JSONParser.JSONParseException {
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("/**/[/**/1/**/, /**/2/**/]/**/"));
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("/*x*/[/*x*/1/*x*/, /*x*/2/*x*/]/*x*/"));
+        assertEquals(ImmutableList.of(1), JSONParser.parse(" /*x*/ /**//**/ [ /*x*/ /*\n*//***/ 1 ]"));
+        try {
+            JSONParser.parse("/*");
+            fail();
+        } catch (JSONParser.JSONParseException e) {
+            assertThat(e.getMessage(), containsString("Unclosed comment"));
+        }
+        try {
+            JSONParser.parse("[/*]");
+            fail();
+        } catch (JSONParser.JSONParseException e) {
+            assertThat(e.getMessage(), containsString("Unclosed comment"));
+        }
+    }
+
+    @Test
+    public void testLineComments() throws JSONParser.JSONParseException {
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("//c1\n[ //c2\n1, //c3\n 2//c5\n] //c4"));
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("// c1\n//\r// c2\r\n// c3\r\n[ 1, 2 ]//"));
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("[1, 2]\n//\n"));
+    }
+
+    @Test
+    public void testWhitespace() throws JSONParser.JSONParseException {
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("  [  1  ,\n2  ]  "));
+        assertEquals(ImmutableList.of(1, 2), JSONParser.parse("\uFEFF[\u00A01\u00A0,2]"));
+    }
+
+    @Test
+    public void testMixed() throws JSONParser.JSONParseException {
+        LinkedHashMap<String, Object> m = new LinkedHashMap<>();
+        m.put("x", 1);
+        m.put("y", null);
+        assertEquals(
+                ImmutableList.of(
+                        ImmutableMap.of("a", Collections.emptyMap()),
+                        ImmutableMap.of("b",
+                                Arrays.asList(
+                                        m,
+                                        true,
+                                        null
+                                ))
+                ),
+                JSONParser.parse("" +
+                        "[\n" +
+                        "{\"a\":{}},\n" +
+                        "{\"b\":\n" +
+                        "[" +
+                        "{\"x\":1, \"y\": null}," +
+                        "true," +
+                        "null" +
+                        "] // comment\n" +
+                        "}\n" +
+                        "]"));
+    }
+
+    private static void assertEquals(Object expected, TemplateModel actual) {
+        try {
+            Assert.assertEquals(expected, DeepUnwrap.unwrap(actual));
+        } catch (TemplateException e) {
+            throw new BugException(e);
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/freemarker-core/src/main/java/org/apache/freemarker/core/ASTExpBuiltIn.java b/freemarker-core/src/main/java/org/apache/freemarker/core/ASTExpBuiltIn.java
index 4102f3e..8500d6d 100644
--- a/freemarker-core/src/main/java/org/apache/freemarker/core/ASTExpBuiltIn.java
+++ b/freemarker-core/src/main/java/org/apache/freemarker/core/ASTExpBuiltIn.java
@@ -61,6 +61,7 @@ import org.apache.freemarker.core.BuiltInsForSequences.seq_index_ofBI;
 import org.apache.freemarker.core.BuiltInsForSequences.sortBI;
 import org.apache.freemarker.core.BuiltInsForSequences.sort_byBI;
 import org.apache.freemarker.core.BuiltInsForStringsMisc.evalBI;
+import org.apache.freemarker.core.BuiltInsForStringsMisc.evalJsonBI;
 import org.apache.freemarker.core.model.TemplateCallableModel;
 import org.apache.freemarker.core.model.TemplateDateModel;
 import org.apache.freemarker.core.model.TemplateModelWithOriginName;
@@ -75,7 +76,7 @@ abstract class ASTExpBuiltIn extends ASTExpression implements Cloneable {
     protected ASTExpression target;
     protected String key;
 
-    static final int NUMBER_OF_BIS = 271;
+    static final int NUMBER_OF_BIS = 272;
     static final HashMap<String, ASTExpBuiltIn> BUILT_INS_BY_NAME = new HashMap(NUMBER_OF_BIS * 3 / 2 + 1, 1f);
 
     static {
@@ -104,6 +105,7 @@ abstract class ASTExpBuiltIn extends ASTExpression implements Cloneable {
         putBI("ensureStartsWith", new BuiltInsForStringsBasic.ensure_starts_withBI());
         putBI("esc", new escBI());
         putBI("eval", new evalBI());
+        putBI("evalJson", new evalJsonBI());
         putBI("first", new firstBI());
         putBI("float", new floatBI());
         putBI("floor", new floorBI());
diff --git a/freemarker-core/src/main/java/org/apache/freemarker/core/BuiltInsForStringsMisc.java b/freemarker-core/src/main/java/org/apache/freemarker/core/BuiltInsForStringsMisc.java
index d5bb4bf..3fcb4e2 100644
--- a/freemarker-core/src/main/java/org/apache/freemarker/core/BuiltInsForStringsMisc.java
+++ b/freemarker-core/src/main/java/org/apache/freemarker/core/BuiltInsForStringsMisc.java
@@ -72,14 +72,14 @@ class BuiltInsForStringsMisc {
     }
 
     static class evalBI extends OutputFormatBoundBuiltIn {
-        
+
         private ParsingConfiguration pCfg;
-        
+
         @Override
         protected TemplateModel calculateResult(Environment env) throws TemplateException {
             return calculateResult(BuiltInForString.getTargetString(target, env), env);
         }
-        
+
         @Override
         void bindToOutputFormat(OutputFormat outputFormat, AutoEscapingPolicy autoEscapingPolicy) {
             super.bindToOutputFormat(outputFormat, autoEscapingPolicy);
@@ -89,12 +89,12 @@ class BuiltInsForStringsMisc {
                 pCfg = new FinalParsingConfiguration(pCfg, pCfg.getTemplateLanguage(), outputFormat, autoEscapingPolicy,
                         template.getConfiguration());
             }
-            this.pCfg = pCfg; 
+            this.pCfg = pCfg;
         }
 
         TemplateModel calculateResult(String s, Environment env) throws TemplateException {
             Template parentTemplate = getTemplate();
-            
+
             ASTExpression exp;
             try {
                 try {
@@ -112,7 +112,7 @@ class BuiltInsForStringsMisc {
                             parentTemplate, false, tkMan,
                             pCfg,
                             null);
-                    
+
                     exp = parser.Expression();
                 } catch (TokenMgrError e) {
                     throw e.toParseException(parentTemplate);
@@ -136,21 +136,37 @@ class BuiltInsForStringsMisc {
                         "\n\nThe failing expression:");
             }
         }
-        
+
     }
-    
+
+    static class evalJsonBI extends BuiltInForString {
+        @Override
+        TemplateModel calculateResult(String s, Environment env) throws TemplateException {
+            try {
+                return JSONParser.parse(s);
+            } catch (JSONParser.JSONParseException e) {
+                throw new TemplateException(e, this, env,
+                        "Failed to \"?", key, "\" string with this error:\n\n",
+                        MessageUtils.EMBEDDED_MESSAGE_BEGIN,
+                        new _DelayedGetMessage(e),
+                        MessageUtils.EMBEDDED_MESSAGE_END,
+                        "\n\nThe failing expression:");
+            }
+        }
+    }
+
     /**
      * A method that takes a parameter and evaluates it as a string,
      * then treats that string as template source code and returns a
      * transform model that evaluates the template in place.
      * The template inherits the configuration and environment of the executing
-     * template. By default, its name will be equal to 
+     * template. By default, its name will be equal to
      * <tt>executingTemplate.getLookupName() + "$anonymous_interpreted"</tt>. You can
      * specify another parameter to the method call in which case the
      * template name suffix is the specified id instead of "anonymous_interpreted".
      */
     static class interpretBI extends OutputFormatBoundBuiltIn {
-        
+
         /**
          * Constructs a template on-the-fly and returns it embedded in a
          * {@link TemplateDirectiveModel}.
@@ -372,5 +388,5 @@ class BuiltInsForStringsMisc {
         }
         
     }
-    
+
 }
diff --git a/freemarker-core/src/main/java/org/apache/freemarker/core/JSONParser.java b/freemarker-core/src/main/java/org/apache/freemarker/core/JSONParser.java
new file mode 100644
index 0000000..5c5ae48
--- /dev/null
+++ b/freemarker-core/src/main/java/org/apache/freemarker/core/JSONParser.java
@@ -0,0 +1,616 @@
+/*
+ * 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.freemarker.core;
+
+import java.math.BigDecimal;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.apache.freemarker.core.model.TemplateBooleanModel;
+import org.apache.freemarker.core.model.TemplateHashModelEx;
+import org.apache.freemarker.core.model.TemplateModel;
+import org.apache.freemarker.core.model.TemplateNullModel;
+import org.apache.freemarker.core.model.TemplateNumberModel;
+import org.apache.freemarker.core.model.TemplateSequenceModel;
+import org.apache.freemarker.core.model.TemplateStringModel;
+import org.apache.freemarker.core.model.impl.SimpleHash;
+import org.apache.freemarker.core.model.impl.SimpleNumber;
+import org.apache.freemarker.core.model.impl.SimpleString;
+import org.apache.freemarker.core.util.BugException;
+import org.apache.freemarker.core.util._NumberUtils;
+import org.apache.freemarker.core.util._StringUtils;
+
+import jdk.nashorn.internal.objects.NativeNumber;
+
+/**
+ * JSON parser that returns a {@link TameplatModel}, similar to what FTL literals product (and so, what
+ * @code ?eval} would return). A notable difference compared to the result FTL literals is that this doesn't use the
+ * {@link ParserConfiguration#getArithmeticEngine()} to parse numbers, as JSON has its own fixed number syntax. For
+ * numbers this parser returns {@link SimpleNumberModel}-s, where the wrapped numbers will be {@link Integer}-s when
+ * they fit into that, otherwise they will be {@link Long}-s if they fit into that, otherwise they will be
+ * {@link BigDecimal}-s.
+ *
+ * <p>This parser allows certain things that are errors in pure JSON:
+ * <ul>
+ *     <li>JavaScript comments are supported</li>
+ *     <li>Non-breaking space (nbsp) and BOM are treated as whitespace</li>
+ * </ul>
+ */
+class JSONParser {
+
+    private static final String UNCLOSED_OBJECT_MESSAGE
+            = "This {...} was still unclosed when the end of the file was reached. (Look for a missing \"}\")";
+
+    private static final String UNCLOSED_ARRAY_MESSAGE
+            = "This [...] was still unclosed when the end of the file was reached. (Look for a missing \"]\")";
+
+    private static final BigDecimal MIN_INT_AS_BIGDECIMAL = BigDecimal.valueOf(Integer.MIN_VALUE);
+    private static final BigDecimal MAX_INT_AS_BIGDECIMAL = BigDecimal.valueOf(Integer.MAX_VALUE);
+    private static final BigDecimal MIN_LONG_AS_BIGDECIMAL = BigDecimal.valueOf(Long.MIN_VALUE);
+    private static final BigDecimal MAX_LONG_AS_BIGDECIMAL = BigDecimal.valueOf(Long.MAX_VALUE);
+
+    private final String src;
+    private final int ln;
+
+    private int p;
+
+    public static TemplateModel parse(String src) throws JSONParseException {
+        return new JSONParser(src).parse();
+    }
+
+    /**
+     * @param sourceLocation Only used in error messages, maybe {@code null}.
+     */
+    private JSONParser(String src) {
+        this.src = src;
+        this.ln = src.length();
+    }
+
+    private TemplateModel parse() throws JSONParseException {
+        skipWS();
+        TemplateModel result = consumeValue("Empty JSON (contains no value)", p);
+
+        skipWS();
+        if (p != ln) {
+            throw newParseException("End-of-file was expected but found further non-whitespace characters.");
+        }
+
+        return result;
+    }
+
+    private TemplateModel consumeValue(String eofErrorMessage, int eofBlamePosition) throws JSONParseException {
+        if (p == ln) {
+            throw newParseException(
+                    eofErrorMessage == null
+                            ? "A value was expected here, but end-of-file was reached." : eofErrorMessage,
+                    eofBlamePosition == -1 ? p : eofBlamePosition);
+        }
+
+        TemplateModel result;
+
+        result = tryConsumeString();
+        if (result != null) return result;
+
+        result = tryConsumeNumber();
+        if (result != null) return result;
+
+        result = tryConsumeObject();
+        if (result != null) return result;
+
+        result = tryConsumeArray();
+        if (result != null) return result;
+
+        result = tryConsumeTrueFalseNull();
+        if (result != null) return result;
+
+        // Better error message for a frequent mistake:
+        if (p < ln && src.charAt(p) == '\'') {
+            throw newParseException("Unexpected apostrophe-quote character. "
+                    + "JSON strings must be quoted with quotation mark.");
+        }
+
+        throw newParseException(
+                "Expected either the beginning of a (negative) number or the beginning of one of these: "
+                        + "{...}, [...], \"...\", true, false, null. Found character "
+                        + _StringUtils.jQuote(src.charAt(p)) + " instead.");
+    }
+
+    private TemplateModel tryConsumeTrueFalseNull() throws JSONParseException {
+        int startP = p;
+        if (p < ln && isIdentifierStart(src.charAt(p))) {
+            p++;
+            while (p < ln && isIdentifierPart(src.charAt(p))) {
+                p++;
+            }
+        }
+
+        if (startP == p) return null;
+
+        String keyword = src.substring(startP, p);
+        if (keyword.equals("true")) {
+            return TemplateBooleanModel.TRUE;
+        } else if (keyword.equals("false")) {
+            return TemplateBooleanModel.FALSE;
+        } else if (keyword.equals("null")) {
+            return TemplateNullModel.INSTANCE;
+        }
+
+        throw newParseException(
+                "Invalid JSON keyword: " + _StringUtils.jQuote(keyword)
+                        + ". Should be one of: true, false, null. "
+                        + "If it meant to be a string then it must be quoted.", startP);
+    }
+
+    private TemplateNumberModel tryConsumeNumber() throws JSONParseException {
+        if (p >= ln) {
+            return null;
+        }
+        char c = src.charAt(p);
+        boolean negative = c == '-';
+        if (!(negative || isDigit(c) || c == '.')) {
+            return null;
+        }
+
+        int startP = p;
+
+        if (negative) {
+            if (p + 1 >= ln) {
+                throw newParseException("Expected a digit after \"-\", but reached end-of-file.");
+            }
+            char lookAheadC = src.charAt(p + 1);
+            if (!(isDigit(lookAheadC) || lookAheadC == '.')) {
+                return null;
+            }
+            p++; // Consume "-" only, not the digit
+        }
+
+        long longSum = 0;
+        boolean firstDigit = true;
+        consumeLongFittingHead: do {
+            c = src.charAt(p);
+
+            if (!isDigit(c)) {
+                if (c == '.' && firstDigit) {
+                    throw newParseException("JSON doesn't allow numbers starting with \".\".");
+                }
+                break consumeLongFittingHead;
+            }
+
+            int digit = c - '0';
+            if (longSum == 0) {
+                if (!firstDigit) {
+                    throw newParseException("JSON doesn't allow superfluous leading 0-s.", p - 1);
+                }
+
+                longSum = !negative ? digit : -digit;
+                p++;
+            } else {
+                long prevLongSum = longSum;
+                longSum = longSum * 10 + (!negative ? digit : -digit);
+                if (!negative && prevLongSum > longSum || negative && prevLongSum < longSum) {
+                    // We had an overflow => Can't consume this digit as long-fitting
+                    break consumeLongFittingHead;
+                }
+                p++;
+            }
+            firstDigit = false;
+        } while (p < ln);
+
+        if (p < ln && isBigDecimalFittingTailCharacter(c)) {
+            char lastC = c;
+            p++;
+
+            consumeBigDecimalFittingTail: while (p < ln) {
+                c = src.charAt(p);
+                if (isBigDecimalFittingTailCharacter(c)) {
+                    p++;
+                } else if ((c == '+' || c == '-') && isE(lastC)) {
+                    p++;
+                } else {
+                    break consumeBigDecimalFittingTail;
+                }
+                lastC = c;
+            }
+
+            String numStr = src.substring(startP, p);
+            BigDecimal bd;
+            try {
+                bd = new BigDecimal(numStr);
+            } catch (NumberFormatException e) {
+                throw new JSONParseException("Malformed number: " + numStr, src, startP, e);
+            }
+
+            if (bd.compareTo(MIN_INT_AS_BIGDECIMAL) >= 0 && bd.compareTo(MAX_INT_AS_BIGDECIMAL) <= 0) {
+                if (_NumberUtils.isIntegerBigDecimal(bd)) {
+                    return new SimpleNumber(bd.intValue());
+                }
+            } else if (bd.compareTo(MIN_LONG_AS_BIGDECIMAL) >= 0 && bd.compareTo(MAX_LONG_AS_BIGDECIMAL) <= 0) {
+                if (_NumberUtils.isIntegerBigDecimal(bd)) {
+                    return new SimpleNumber(bd.longValue());
+                }
+            }
+            return new SimpleNumber(bd);
+        } else {
+            return new SimpleNumber(
+                    longSum <= Integer.MAX_VALUE && longSum >= Integer.MIN_VALUE
+                            ? (Number) (int) longSum
+                            : longSum);
+        }
+    }
+
+    private TemplateStringModel tryConsumeString() throws JSONParseException {
+        int startP = p;
+        if (!tryConsumeChar('"')) return null;
+
+        StringBuilder sb = new StringBuilder();
+        char c = 0;
+        while (p < ln) {
+            c = src.charAt(p);
+
+            if (c == '"') {
+                p++;
+                return new SimpleString(sb.toString());  // Call normally returns here!
+            } else if (c == '\\') {
+                p++;
+                sb.append(consumeAfterBackslash());
+            } else if (c <= 0x1F) {
+                throw newParseException("JSON doesn't allow unescaped control characters in string literals, "
+                        + "but found character with code (decimal): " + (int) c);
+            } else {
+                p++;
+                sb.append(c);
+            }
+        }
+
+        throw newParseException("String literal was still unclosed when the end of the file was reached. "
+                + "(Look for missing or accidentally escaped closing quotation mark.)", startP);
+    }
+
+    private TemplateSequenceModel tryConsumeArray() throws JSONParseException {
+        int startP = p;
+        if (!tryConsumeChar('[')) return null;
+
+        skipWS();
+        if (tryConsumeChar(']')) return TemplateSequenceModel.EMPTY_SEQUENCE;
+
+        boolean afterComma = false;
+        NativeSequence elements = new NativeSequence();
+        do {
+            skipWS();
+            elements.add(consumeValue(afterComma ? null : UNCLOSED_ARRAY_MESSAGE, afterComma ? -1 : startP));
+
+            skipWS();
+            afterComma = true;
+        } while (consumeChar(',', ']', UNCLOSED_ARRAY_MESSAGE, startP) == ',');
+        return elements;
+    }
+
+    private TemplateHashModelEx tryConsumeObject() throws JSONParseException {
+        int startP = p;
+        if (!tryConsumeChar('{')) return null;
+
+        skipWS();
+        if (tryConsumeChar('}')) return TemplateHashModelEx.EMPTY_HASH;
+
+        boolean afterComma = false;
+        NativeHashEx hash = new NativeHashEx();
+        do {
+            skipWS();
+            int keyStartP = p;
+            Object key = consumeValue(afterComma ? null : UNCLOSED_OBJECT_MESSAGE, afterComma ? -1 : startP);
+            if (!(key instanceof TemplateStringModel)) {
+                throw newParseException("Wrong key type. JSON only allows string keys inside {...}.", keyStartP);
+            }
+            String strKey = null;
+            try {
+                strKey = ((TemplateStringModel) key).getAsString();
+            } catch (TemplateException e) {
+                throw new BugException(e);
+            }
+
+            skipWS();
+            consumeChar(':');
+
+            skipWS();
+            hash.put(strKey, consumeValue(null, -1));
+
+            skipWS();
+            afterComma = true;
+        } while (consumeChar(',', '}', UNCLOSED_OBJECT_MESSAGE, startP) == ',');
+        return hash;
+    }
+
+    private boolean isE(char c) {
+        return c == 'e' || c == 'E';
+    }
+
+    private boolean isBigDecimalFittingTailCharacter(char c) {
+        return c == '.' || isE(c) || isDigit(c);
+    }
+
+    private char consumeAfterBackslash() throws JSONParseException {
+        if (p == ln) {
+            throw newParseException("Reached the end of the file, but the escape is unclosed.");
+        }
+
+        final char c = src.charAt(p);
+        switch (c) {
+            case '"':
+            case '\\':
+            case '/':
+                p++;
+                return c;
+            case 'b':
+                p++;
+                return '\b';
+            case 'f':
+                p++;
+                return '\f';
+            case 'n':
+                p++;
+                return '\n';
+            case 'r':
+                p++;
+                return '\r';
+            case 't':
+                p++;
+                return '\t';
+            case 'u':
+                p++;
+                return consumeAfterBackslashU();
+        }
+        throw newParseException("Unsupported escape: \\" + c);
+    }
+
+    private char consumeAfterBackslashU() throws JSONParseException {
+        if (p + 3 >= ln) {
+            throw newParseException("\\u must be followed by exactly 4 hexadecimal digits");
+        }
+        final String hex = src.substring(p, p + 4);
+        try {
+            char r = (char) Integer.parseInt(hex, 16);
+            p += 4;
+            return r;
+        } catch (NumberFormatException e) {
+            throw newParseException("\\u must be followed by exactly 4 hexadecimal digits, but was followed by "
+                    + _StringUtils.jQuote(hex) + ".");
+        }
+    }
+
+    private boolean tryConsumeChar(char c) {
+        if (p < ln && src.charAt(p) == c) {
+            p++;
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    private void consumeChar(char expected) throws JSONParseException {
+        consumeChar(expected, (char) 0, null, -1);
+    }
+
+    private char consumeChar(char expected1, char expected2, String eofErrorHint, int eofErrorP) throws JSONParseException {
+        if (p >= ln) {
+            throw newParseException(eofErrorHint == null
+                            ? "Expected " + _StringUtils.jQuote(expected1)
+                            + ( expected2 != 0 ? " or " + _StringUtils.jQuote(expected2) : "")
+                            + " character, but reached end-of-file. "
+                            : eofErrorHint,
+                    eofErrorP == -1 ? p : eofErrorP);
+        }
+        char c = src.charAt(p);
+        if (c == expected1 || (expected2 != 0 && c == expected2)) {
+            p++;
+            return c;
+        }
+        throw newParseException("Expected " + _StringUtils.jQuote(expected1)
+                + ( expected2 != 0 ? " or " + _StringUtils.jQuote(expected2) : "")
+                + " character, but found " + _StringUtils.jQuote(c) + " instead.");
+    }
+
+    private void skipWS() throws JSONParseException {
+        do {
+            while (p < ln && isWS(src.charAt(p))) {
+                p++;
+            }
+        } while (skipComment());
+    }
+
+    private boolean skipComment() throws JSONParseException {
+        if (p + 1 < ln) {
+            if (src.charAt(p) == '/') {
+                char c2 = src.charAt(p + 1);
+                if (c2 == '/') {
+                    int eolP = p + 2;
+                    while (eolP < ln && !isLineBreak(src.charAt(eolP))) {
+                        eolP++;
+                    }
+                    p = eolP;
+                    return true;
+                } else if (c2 == '*') {
+                    int closerP = p + 3;
+                    while (closerP < ln && !(src.charAt(closerP - 1) == '*' && src.charAt(closerP) == '/')) {
+                        closerP++;
+                    }
+                    if (closerP >= ln) {
+                        throw newParseException("Unclosed comment");
+                    }
+                    p = closerP + 1;
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Whitespace as specified by JSON, plus non-breaking space (nbsp), and BOM.
+     */
+    private static boolean isWS(char c) {
+        return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == 0xA0 || c == '\uFEFF';
+    }
+
+    private static boolean isLineBreak(char c) {
+        return c == '\r' || c == '\n';
+    }
+
+    private static boolean isIdentifierStart(char c) {
+        return Character.isLetter(c) || c == '_' || c == '$';
+    }
+
+    private static boolean isDigit(char c) {
+        return c >= '0' && c <= '9';
+    }
+
+    private static boolean isIdentifierPart(char c) {
+        return isIdentifierStart(c) || isDigit(c);
+    }
+
+    private JSONParseException newParseException(String message) {
+        return newParseException(message, p);
+    }
+
+    private JSONParseException newParseException(String message, int p) {
+        return new JSONParseException(message, src, p);
+    }
+
+    static class JSONParseException extends Exception {
+        public JSONParseException(String message, String src, int position) {
+            super(createSourceCodeErrorMessage(message, src, position));
+        }
+
+        public JSONParseException(String message, String src, int position,
+                Throwable cause) {
+            super(createSourceCodeErrorMessage(message, src, position), cause);
+        }
+
+    }
+
+    private static int MAX_QUOTATION_LENGTH = 50;
+
+    private static String createSourceCodeErrorMessage(String message, String srcCode, int position) {
+        int ln = srcCode.length();
+        if (position < 0) {
+            position = 0;
+        }
+        if (position >= ln) {
+            return message + "\n"
+                    + "Error location: At the end of text.";
+        }
+
+        int i;
+        char c;
+        int rowBegin = 0;
+        int rowEnd;
+        int row = 1;
+        char lastChar = 0;
+        for (i = 0; i <= position; i++) {
+            c = srcCode.charAt(i);
+            if (lastChar == 0xA) {
+                rowBegin = i;
+                row++;
+            } else if (lastChar == 0xD && c != 0xA) {
+                rowBegin = i;
+                row++;
+            }
+            lastChar = c;
+        }
+        for (i = position; i < ln; i++) {
+            c = srcCode.charAt(i);
+            if (c == 0xA || c == 0xD) {
+                if (c == 0xA && i > 0 && srcCode.charAt(i - 1) == 0xD) {
+                    i--;
+                }
+                break;
+            }
+        }
+        rowEnd = i - 1;
+        if (position > rowEnd + 1) {
+            position = rowEnd + 1;
+        }
+        int col = position - rowBegin + 1;
+        if (rowBegin > rowEnd) {
+            return message + "\n"
+                    + "Error location: line "
+                    + row + ", column " + col + ":\n"
+                    + "(Can't show the line because it is empty.)";
+        }
+        String s1 = srcCode.substring(rowBegin, position);
+        String s2 = srcCode.substring(position, rowEnd + 1);
+        s1 = expandTabs(s1, 8);
+        int ln1 = s1.length();
+        s2 = expandTabs(s2, 8, ln1);
+        int ln2 = s2.length();
+        if (ln1 + ln2 > MAX_QUOTATION_LENGTH) {
+            int newLn2 = ln2 - ((ln1 + ln2) - MAX_QUOTATION_LENGTH);
+            if (newLn2 < 6) {
+                newLn2 = 6;
+            }
+            if (newLn2 < ln2) {
+                s2 = s2.substring(0, newLn2 - 3) + "...";
+                ln2 = newLn2;
+            }
+            if (ln1 + ln2 > MAX_QUOTATION_LENGTH) {
+                s1 = "..." + s1.substring((ln1 + ln2) - MAX_QUOTATION_LENGTH + 3);
+            }
+        }
+        StringBuilder res = new StringBuilder(message.length() + 80);
+        res.append(message);
+        res.append("\nError location: line ").append(row).append(", column ").append(col).append(":\n");
+        res.append(s1).append(s2).append("\n");
+        int x = s1.length();
+        while (x != 0) {
+            res.append(' ');
+            x--;
+        }
+        res.append('^');
+
+        return res.toString();
+    }
+
+    private static String expandTabs(String s, int tabWidth) {
+        return expandTabs(s, tabWidth, 0);
+    }
+
+    /**
+     * Replaces all tab-s with spaces in a single line.
+     */
+    private static String expandTabs(String s, int tabWidth, int startCol) {
+        int e = s.indexOf('\t');
+        if (e == -1) {
+            return s;
+        }
+        int b = 0;
+        StringBuilder buf = new StringBuilder(s.length() + Math.max(16, tabWidth * 2));
+        do {
+            buf.append(s, b, e);
+            int col = buf.length() + startCol;
+            for (int i = tabWidth * (1 + col / tabWidth) - col; i > 0; i--) {
+                buf.append(' ');
+            }
+            b = e + 1;
+            e = s.indexOf('\t', b);
+        } while (e != -1);
+        buf.append(s, b, s.length());
+        return buf.toString();
+    }
+
+}