freemarker-core/src/main/java/freemarker/core/_MessageUtil.java - freemarker - Git at Google

 /*
  * 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 freemarker.core;

 import java.util.ArrayList;

 import freemarker.template.Template;
 import freemarker.template.TemplateException;
 import freemarker.template.TemplateHashModelEx;
 import freemarker.template.TemplateHashModelEx2;
 import freemarker.template.TemplateModel;
 import freemarker.template.TemplateModelException;
 import freemarker.template.utility.StringUtil;

 /**
  * Used internally only, might change without notice!
  * Utilities for creating error messages (and other messages).
  */
 public class _MessageUtil {

     static final String UNKNOWN_DATE_TO_STRING_ERROR_MESSAGE
             = "Can't convert the date-like value to string because it isn't "
               + "known if it's a date (no time part), time or date-time value.";

     static final String UNKNOWN_DATE_PARSING_ERROR_MESSAGE
             = "Can't parse the string to date-like value because it isn't "
               + "known if it's desired result should be a date (no time part), a time, or a date-time value.";

     static final String UNKNOWN_DATE_TYPE_ERROR_TIP =
             "Use ?date, ?time, or ?datetime to tell FreeMarker the exact type.";

     static final Object[] UNKNOWN_DATE_TO_STRING_TIPS = {
             UNKNOWN_DATE_TYPE_ERROR_TIP,
             "If you need a particular format only once, use ?string(pattern), like ?string('dd.MM.yyyy HH:mm:ss'), "
             + "to specify which fields to display. "
     };

     static final String EMBEDDED_MESSAGE_BEGIN = "---begin-message---\n";

     static final String EMBEDDED_MESSAGE_END = "\n---end-message---";

     // Can't be instantiated
     private _MessageUtil() { }

     static String formatLocationForSimpleParsingError(Template template, int line, int column) {
         return formatLocation("in", template, line, column);
     }

     static String formatLocationForSimpleParsingError(String templateSourceName, int line, int column) {
         return formatLocation("in", templateSourceName, line, column);
     }

     static String formatLocationForDependentParsingError(Template template, int line, int column) {
         return formatLocation("on", template, line, column);
     }

     static String formatLocationForDependentParsingError(String templateSourceName, int line, int column) {
         return formatLocation("on", templateSourceName, line, column);
     }

     static String formatLocationForEvaluationError(Template template, int line, int column) {
         return formatLocation("at", template, line, column);
     }

     static String formatLocationForEvaluationError(Macro macro, int line, int column) {
         Template t = macro.getTemplate();
         return formatLocation("at", t != null ? t.getSourceName() : null, macro.getName(), macro.isFunction(), line, column);
     }

     static String formatLocationForEvaluationError(String templateSourceName, int line, int column) {
         return formatLocation("at", templateSourceName, line, column);
     }

     private static String formatLocation(String preposition, Template template, int line, int column) {
         return formatLocation(preposition, template != null ? template.getSourceName() : null, line, column);
     }

     private static String formatLocation(String preposition, String templateSourceName, int line, int column) {
         return formatLocation(
                 preposition, templateSourceName,
                 null, false,
                 line, column);
     }

     private static String formatLocation(
             String preposition, String templateSourceName,
             String macroOrFuncName, boolean isFunction,
             int line, int column) {
         String templateDesc;
         if (line < 0) {
             templateDesc = "?eval-ed string";
             macroOrFuncName = null;
         } else {
             templateDesc = templateSourceName != null
                 ? "template " + StringUtil.jQuoteNoXSS(templateSourceName)
                 : "nameless template";
         }
         return "in " + templateDesc
               + (macroOrFuncName != null
                       ? " in " + (isFunction ? "function " : "macro ") + StringUtil.jQuote(macroOrFuncName)
                       : "")
               + " "
               + preposition + " " + formatPosition(line, column);
     }

     static String formatPosition(int line, int column) {
         return "line " + (line >= 0 ? line : line - (TemplateObject.RUNTIME_EVAL_LINE_DISPLACEMENT - 1))
                 + ", column " + column;
     }

     /**
      * Returns a single line string that is no longer than {@code maxLength}.
      * If will truncate the string at line-breaks too.
      * The truncation is always signaled with a a {@code "..."} at the end of the result string.
      */
     public static String shorten(String s, int maxLength) {
         if (maxLength < 5) maxLength = 5;

         boolean isTruncated = false;

         int brIdx = s.indexOf('\n');
         if (brIdx != -1) {
             s = s.substring(0, brIdx);
             isTruncated = true;
         };
         brIdx = s.indexOf('\r');
         if (brIdx != -1) {
             s = s.substring(0, brIdx);
             isTruncated = true;
         }

         if (s.length() > maxLength) {
             s = s.substring(0, maxLength - 3);
             isTruncated = true;
         }

         if (!isTruncated) {
             return s;
         } else {
             if (s.endsWith(".")) {
                 if (s.endsWith("..")) {
                     if (s.endsWith("...")) {
                         return s;
                     } else {
                         return s + ".";
                     }
                 } else {
                     return s + "..";
                 }
             } else {
                 return s + "...";
             }
         }
     }

     public static StringBuilder appendExpressionAsUntearable(StringBuilder sb, Expression argExp) {
         boolean needParen =
                 !(argExp instanceof NumberLiteral)
                 && !(argExp instanceof StringLiteral)
                 && !(argExp instanceof BooleanLiteral)
                 && !(argExp instanceof ListLiteral)
                 && !(argExp instanceof HashLiteral)
                 && !(argExp instanceof Identifier)
                 && !(argExp instanceof Dot)
                 && !(argExp instanceof DynamicKeyName)
                 && !(argExp instanceof MethodCall)
                 && !(argExp instanceof BuiltIn)
                 && !(argExp instanceof ExistsExpression)
                 && !(argExp instanceof ParentheticalExpression);
         if (needParen) sb.append('(');
         sb.append(argExp.getCanonicalForm());
         if (needParen) sb.append(')');
         return sb;
     }

     public static TemplateModelException newArgCntError(String methodName, int argCnt, int expectedCnt) {
         return newArgCntError(methodName, argCnt, expectedCnt, expectedCnt);
     }

     public static TemplateModelException newArgCntError(String methodName, int argCnt, int minCnt, int maxCnt) {
         ArrayList/*<Object>*/ desc = new ArrayList(20);

         desc.add(methodName);

         desc.add("(");
         if (maxCnt != 0) desc.add("...");
         desc.add(") expects ");

         if (minCnt == maxCnt) {
             if (maxCnt == 0) {
                 desc.add("no");
             } else {
                 desc.add(Integer.valueOf(maxCnt));
             }
         } else if (maxCnt - minCnt == 1) {
             desc.add(Integer.valueOf(minCnt));
             desc.add(" or ");
             desc.add(Integer.valueOf(maxCnt));
         } else {
             desc.add(Integer.valueOf(minCnt));
             if (maxCnt != Integer.MAX_VALUE) {
                 desc.add(" to ");
                 desc.add(Integer.valueOf(maxCnt));
             } else {
                 desc.add(" or more (unlimited)");
             }
         }
         desc.add(" argument");
         if (maxCnt > 1) desc.add("s");

         desc.add(" but has received ");
         if (argCnt == 0) {
             desc.add("none");
         } else {
             desc.add(Integer.valueOf(argCnt));
         }
         desc.add(".");

         return new _TemplateModelException(desc.toArray());
     }

     public static TemplateModelException newMethodArgMustBeStringException(String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "string", arg);
     }

     public static TemplateModelException newMethodArgMustBeNumberException(String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "number", arg);
     }

     public static TemplateModelException newMethodArgMustBeBooleanException(String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "boolean", arg);
     }

     public static TemplateModelException newMethodArgMustBeExtendedHashException(
             String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "extended hash", arg);
     }

     public static TemplateModelException newMethodArgMustBeExtendedHashOrSequnceException(
             String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "extended hash or sequence", arg);
     }

     public static TemplateModelException newMethodArgMustBeSequenceException(
             String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "sequence", arg);
     }

     public static TemplateModelException newMethodArgMustBeSequenceOrCollectionException(
             String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "sequence or collection", arg);
     }

     public static TemplateModelException newMethodArgMustBeStringOrMarkupOutputException(
             String methodName, int argIdx, TemplateModel arg) {
         return newMethodArgUnexpectedTypeException(methodName, argIdx, "string or markup output", arg);
     }

     public static TemplateModelException newMethodArgUnexpectedTypeException(
             String methodName, int argIdx, String expectedType, TemplateModel arg) {
         return new _TemplateModelException(
                 methodName, "(...) expects ", new _DelayedAOrAn(expectedType), " as argument #", Integer.valueOf(argIdx + 1),
                 ", but received ", new _DelayedAOrAn(new _DelayedFTLTypeDescription(arg)), ".");
     }

     /**
      * The type of the argument was good, but it's value wasn't.
      */
     public static TemplateModelException newMethodArgInvalidValueException(
             String methodName, int argIdx, Object... details) {
         return new _TemplateModelException(
                 methodName, "(...) argument #", Integer.valueOf(argIdx + 1),
                 " had invalid value: ", details);
     }

     /**
      * The type of the argument was good, but the values of two or more arguments are inconsistent with each other.
      */
     public static TemplateModelException newMethodArgsInvalidValueException(
             String methodName, Object... details) {
         return new _TemplateModelException(methodName, "(...) arguments have invalid value: ", details);
     }

     public static TemplateException newInstantiatingClassNotAllowedException(String className, Environment env) {
         return new _MiscTemplateException(env,
                 "Instantiating ", className, " is not allowed in the template for security reasons.");
     }

     public static _TemplateModelException newCantFormatUnknownTypeDateException(
             Expression dateSourceExpr, UnknownDateTypeFormattingUnsupportedException cause) {
         return new _TemplateModelException(cause, null, new _ErrorDescriptionBuilder(
                 _MessageUtil.UNKNOWN_DATE_TO_STRING_ERROR_MESSAGE)
                 .blame(dateSourceExpr)
                 .tips(_MessageUtil.UNKNOWN_DATE_TO_STRING_TIPS));
     }

     public static TemplateException newCantFormatDateException(TemplateDateFormat format, Expression dataSrcExp,
             TemplateValueFormatException e, boolean useTempModelExc) {
         _ErrorDescriptionBuilder desc = new _ErrorDescriptionBuilder(
                 "Failed to format date/time/datetime with format ", new _DelayedJQuote(format.getDescription()), ": ",
                 e.getMessage())
                 .blame(dataSrcExp);
         return useTempModelExc
                 ? new _TemplateModelException(e, null, desc)
                 : new _MiscTemplateException(e, null, desc);
     }

     public static TemplateException newCantFormatNumberException(TemplateNumberFormat format, Expression dataSrcExp,
             TemplateValueFormatException e, boolean useTempModelExc) {
         _ErrorDescriptionBuilder desc = new _ErrorDescriptionBuilder(
                 "Failed to format number with format ", new _DelayedJQuote(format.getDescription()), ": ",
                 e.getMessage())
                 .blame(dataSrcExp);
         return useTempModelExc
                 ? new _TemplateModelException(e, null, desc)
                 : new _MiscTemplateException(e, null, desc);
     }

     public static TemplateModelException newKeyValuePairListingNonStringKeyExceptionMessage(
             TemplateModel key, TemplateHashModelEx listedHashEx) {
         return new _TemplateModelException(new _ErrorDescriptionBuilder(
                 "When listing key-value pairs of traditional hash "
                 + "implementations, all keys must be strings, but one of them "
                 + "was ",
                 new _DelayedAOrAn(new _DelayedFTLTypeDescription(key)), "."
                 ).tip("The listed value's TemplateModel class was ",
                         new _DelayedShortClassName(listedHashEx.getClass()),
                         ", which doesn't implement ",
                         new _DelayedShortClassName(TemplateHashModelEx2.class),
                         ", which leads to this restriction."));
     }

     /**
      * Because of the limitations of FTL lambdas (called "local lambdas"), sometimes we must condense the lazy result
      * down into a sequence. However, doing that automatically is only allowed if the input was a sequence as well. If
      * it wasn't a sequence, we don't dare to collect the result into a sequence automatically (because it's possibly
      * too long), and that's when this error message comes.
      */
     public static TemplateException newLazilyGeneratedCollectionMustBeSequenceException(Expression blamed) {
         return new _MiscTemplateException(blamed,
                 "The result is a listable value with lazy transformation(s) applied on it, but it's not " +
                 "an FTL sequence (it's not a List-like value, but an Iterator-like value). The place doesn't " +
                 "support such values due to technical limitations. So either pass it to a construct that supports " +
                 "such values (like ", "<#list transformedListable as x>", "), or, if you know that you don't have " +
                 "too many elements, use transformedListable?sequence to allow it to be treated as an FTL sequence.");
     }

     /**
      * @return "a" or "an" or "a(n)" (or "" for empty string) for an FTL type name
      */
     static public String getAOrAn(String s) {
         if (s == null) return null;
         if (s.length() == 0) return "";

         char fc = Character.toLowerCase(s.charAt(0));
         if (fc == 'a' || fc == 'e' || fc == 'i') {
             return "an";
         } else if (fc == 'h') {
             String ls = s.toLowerCase();
             if (ls.startsWith("has") || ls.startsWith("hi")) {
                 return "a";
             } else if (ls.startsWith("ht")) {
                 return "an";
             } else {
                 return "a(n)";
             }
         } else if (fc == 'u' || fc == 'o') {
             return "a(n)";
         } else {
             char sc = (s.length() > 1) ? s.charAt(1) : '\0';
             if (fc == 'x' && !(sc == 'a' || sc == 'e' || sc == 'i' || sc == 'a' || sc == 'o' || sc == 'u')) {
                 return "an";
             } else {
                 return "a";
             }
         }
     }
 }
	/*
	* 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 freemarker.core;

	import java.util.ArrayList;

	import freemarker.template.Template;
	import freemarker.template.TemplateException;
	import freemarker.template.TemplateHashModelEx;
	import freemarker.template.TemplateHashModelEx2;
	import freemarker.template.TemplateModel;
	import freemarker.template.TemplateModelException;
	import freemarker.template.utility.StringUtil;

	/**
	* Used internally only, might change without notice!
	* Utilities for creating error messages (and other messages).
	*/
	public class _MessageUtil {

	static final String UNKNOWN_DATE_TO_STRING_ERROR_MESSAGE
	= "Can't convert the date-like value to string because it isn't "
	+ "known if it's a date (no time part), time or date-time value.";

	static final String UNKNOWN_DATE_PARSING_ERROR_MESSAGE
	= "Can't parse the string to date-like value because it isn't "
	+ "known if it's desired result should be a date (no time part), a time, or a date-time value.";

	static final String UNKNOWN_DATE_TYPE_ERROR_TIP =
	"Use ?date, ?time, or ?datetime to tell FreeMarker the exact type.";

	static final Object[] UNKNOWN_DATE_TO_STRING_TIPS = {
	UNKNOWN_DATE_TYPE_ERROR_TIP,
	"If you need a particular format only once, use ?string(pattern), like ?string('dd.MM.yyyy HH:mm:ss'), "
	+ "to specify which fields to display. "
	};

	static final String EMBEDDED_MESSAGE_BEGIN = "---begin-message---\n";

	static final String EMBEDDED_MESSAGE_END = "\n---end-message---";

	// Can't be instantiated
	private _MessageUtil() { }

	static String formatLocationForSimpleParsingError(Template template, int line, int column) {
	return formatLocation("in", template, line, column);
	}

	static String formatLocationForSimpleParsingError(String templateSourceName, int line, int column) {
	return formatLocation("in", templateSourceName, line, column);
	}

	static String formatLocationForDependentParsingError(Template template, int line, int column) {
	return formatLocation("on", template, line, column);
	}

	static String formatLocationForDependentParsingError(String templateSourceName, int line, int column) {
	return formatLocation("on", templateSourceName, line, column);
	}

	static String formatLocationForEvaluationError(Template template, int line, int column) {
	return formatLocation("at", template, line, column);
	}

	static String formatLocationForEvaluationError(Macro macro, int line, int column) {
	Template t = macro.getTemplate();
	return formatLocation("at", t != null ? t.getSourceName() : null, macro.getName(), macro.isFunction(), line, column);
	}

	static String formatLocationForEvaluationError(String templateSourceName, int line, int column) {
	return formatLocation("at", templateSourceName, line, column);
	}

	private static String formatLocation(String preposition, Template template, int line, int column) {
	return formatLocation(preposition, template != null ? template.getSourceName() : null, line, column);
	}

	private static String formatLocation(String preposition, String templateSourceName, int line, int column) {
	return formatLocation(
	preposition, templateSourceName,
	null, false,
	line, column);
	}

	private static String formatLocation(
	String preposition, String templateSourceName,
	String macroOrFuncName, boolean isFunction,
	int line, int column) {
	String templateDesc;
	if (line < 0) {
	templateDesc = "?eval-ed string";
	macroOrFuncName = null;
	} else {
	templateDesc = templateSourceName != null
	? "template " + StringUtil.jQuoteNoXSS(templateSourceName)
	: "nameless template";
	}
	return "in " + templateDesc
	+ (macroOrFuncName != null
	? " in " + (isFunction ? "function " : "macro ") + StringUtil.jQuote(macroOrFuncName)
	: "")
	+ " "
	+ preposition + " " + formatPosition(line, column);
	}

	static String formatPosition(int line, int column) {
	return "line " + (line >= 0 ? line : line - (TemplateObject.RUNTIME_EVAL_LINE_DISPLACEMENT - 1))
	+ ", column " + column;
	}

	/**
	* Returns a single line string that is no longer than {@code maxLength}.
	* If will truncate the string at line-breaks too.
	* The truncation is always signaled with a a {@code "..."} at the end of the result string.
	*/
	public static String shorten(String s, int maxLength) {
	if (maxLength < 5) maxLength = 5;

	boolean isTruncated = false;

	int brIdx = s.indexOf('\n');
	if (brIdx != -1) {
	s = s.substring(0, brIdx);
	isTruncated = true;
	};
	brIdx = s.indexOf('\r');
	if (brIdx != -1) {
	s = s.substring(0, brIdx);
	isTruncated = true;
	}

	if (s.length() > maxLength) {
	s = s.substring(0, maxLength - 3);
	isTruncated = true;
	}

	if (!isTruncated) {
	return s;
	} else {
	if (s.endsWith(".")) {
	if (s.endsWith("..")) {
	if (s.endsWith("...")) {
	return s;
	} else {
	return s + ".";
	}
	} else {
	return s + "..";
	}
	} else {
	return s + "...";
	}
	}
	}

	public static StringBuilder appendExpressionAsUntearable(StringBuilder sb, Expression argExp) {
	boolean needParen =
	!(argExp instanceof NumberLiteral)
	&& !(argExp instanceof StringLiteral)
	&& !(argExp instanceof BooleanLiteral)
	&& !(argExp instanceof ListLiteral)
	&& !(argExp instanceof HashLiteral)
	&& !(argExp instanceof Identifier)
	&& !(argExp instanceof Dot)
	&& !(argExp instanceof DynamicKeyName)
	&& !(argExp instanceof MethodCall)
	&& !(argExp instanceof BuiltIn)
	&& !(argExp instanceof ExistsExpression)
	&& !(argExp instanceof ParentheticalExpression);
	if (needParen) sb.append('(');
	sb.append(argExp.getCanonicalForm());
	if (needParen) sb.append(')');
	return sb;
	}

	public static TemplateModelException newArgCntError(String methodName, int argCnt, int expectedCnt) {
	return newArgCntError(methodName, argCnt, expectedCnt, expectedCnt);
	}

	public static TemplateModelException newArgCntError(String methodName, int argCnt, int minCnt, int maxCnt) {
	ArrayList/<Object>/ desc = new ArrayList(20);

	desc.add(methodName);

	desc.add("(");
	if (maxCnt != 0) desc.add("...");
	desc.add(") expects ");

	if (minCnt == maxCnt) {
	if (maxCnt == 0) {
	desc.add("no");
	} else {
	desc.add(Integer.valueOf(maxCnt));
	}
	} else if (maxCnt - minCnt == 1) {
	desc.add(Integer.valueOf(minCnt));
	desc.add(" or ");
	desc.add(Integer.valueOf(maxCnt));
	} else {
	desc.add(Integer.valueOf(minCnt));
	if (maxCnt != Integer.MAX_VALUE) {
	desc.add(" to ");
	desc.add(Integer.valueOf(maxCnt));
	} else {
	desc.add(" or more (unlimited)");
	}
	}
	desc.add(" argument");
	if (maxCnt > 1) desc.add("s");

	desc.add(" but has received ");
	if (argCnt == 0) {
	desc.add("none");
	} else {
	desc.add(Integer.valueOf(argCnt));
	}
	desc.add(".");

	return new _TemplateModelException(desc.toArray());
	}

	public static TemplateModelException newMethodArgMustBeStringException(String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "string", arg);
	}

	public static TemplateModelException newMethodArgMustBeNumberException(String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "number", arg);
	}

	public static TemplateModelException newMethodArgMustBeBooleanException(String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "boolean", arg);
	}

	public static TemplateModelException newMethodArgMustBeExtendedHashException(
	String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "extended hash", arg);
	}

	public static TemplateModelException newMethodArgMustBeExtendedHashOrSequnceException(
	String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "extended hash or sequence", arg);
	}

	public static TemplateModelException newMethodArgMustBeSequenceException(
	String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "sequence", arg);
	}

	public static TemplateModelException newMethodArgMustBeSequenceOrCollectionException(
	String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "sequence or collection", arg);
	}

	public static TemplateModelException newMethodArgMustBeStringOrMarkupOutputException(
	String methodName, int argIdx, TemplateModel arg) {
	return newMethodArgUnexpectedTypeException(methodName, argIdx, "string or markup output", arg);
	}

	public static TemplateModelException newMethodArgUnexpectedTypeException(
	String methodName, int argIdx, String expectedType, TemplateModel arg) {
	return new _TemplateModelException(
	methodName, "(...) expects ", new _DelayedAOrAn(expectedType), " as argument #", Integer.valueOf(argIdx + 1),
	", but received ", new _DelayedAOrAn(new _DelayedFTLTypeDescription(arg)), ".");
	}

	/**
	* The type of the argument was good, but it's value wasn't.
	*/
	public static TemplateModelException newMethodArgInvalidValueException(
	String methodName, int argIdx, Object... details) {
	return new _TemplateModelException(
	methodName, "(...) argument #", Integer.valueOf(argIdx + 1),
	" had invalid value: ", details);
	}

	/**
	* The type of the argument was good, but the values of two or more arguments are inconsistent with each other.
	*/
	public static TemplateModelException newMethodArgsInvalidValueException(
	String methodName, Object... details) {
	return new _TemplateModelException(methodName, "(...) arguments have invalid value: ", details);
	}

	public static TemplateException newInstantiatingClassNotAllowedException(String className, Environment env) {
	return new _MiscTemplateException(env,
	"Instantiating ", className, " is not allowed in the template for security reasons.");
	}

	public static _TemplateModelException newCantFormatUnknownTypeDateException(
	Expression dateSourceExpr, UnknownDateTypeFormattingUnsupportedException cause) {
	return new _TemplateModelException(cause, null, new _ErrorDescriptionBuilder(
	_MessageUtil.UNKNOWN_DATE_TO_STRING_ERROR_MESSAGE)
	.blame(dateSourceExpr)
	.tips(_MessageUtil.UNKNOWN_DATE_TO_STRING_TIPS));
	}

	public static TemplateException newCantFormatDateException(TemplateDateFormat format, Expression dataSrcExp,
	TemplateValueFormatException e, boolean useTempModelExc) {
	_ErrorDescriptionBuilder desc = new _ErrorDescriptionBuilder(
	"Failed to format date/time/datetime with format ", new _DelayedJQuote(format.getDescription()), ": ",
	e.getMessage())
	.blame(dataSrcExp);
	return useTempModelExc
	? new _TemplateModelException(e, null, desc)
	: new _MiscTemplateException(e, null, desc);
	}

	public static TemplateException newCantFormatNumberException(TemplateNumberFormat format, Expression dataSrcExp,
	TemplateValueFormatException e, boolean useTempModelExc) {
	_ErrorDescriptionBuilder desc = new _ErrorDescriptionBuilder(
	"Failed to format number with format ", new _DelayedJQuote(format.getDescription()), ": ",
	e.getMessage())
	.blame(dataSrcExp);
	return useTempModelExc
	? new _TemplateModelException(e, null, desc)
	: new _MiscTemplateException(e, null, desc);
	}

	public static TemplateModelException newKeyValuePairListingNonStringKeyExceptionMessage(
	TemplateModel key, TemplateHashModelEx listedHashEx) {
	return new _TemplateModelException(new _ErrorDescriptionBuilder(
	"When listing key-value pairs of traditional hash "
	+ "implementations, all keys must be strings, but one of them "
	+ "was ",
	new _DelayedAOrAn(new _DelayedFTLTypeDescription(key)), "."
	).tip("The listed value's TemplateModel class was ",
	new _DelayedShortClassName(listedHashEx.getClass()),
	", which doesn't implement ",
	new _DelayedShortClassName(TemplateHashModelEx2.class),
	", which leads to this restriction."));
	}

	/**
	* Because of the limitations of FTL lambdas (called "local lambdas"), sometimes we must condense the lazy result
	* down into a sequence. However, doing that automatically is only allowed if the input was a sequence as well. If
	* it wasn't a sequence, we don't dare to collect the result into a sequence automatically (because it's possibly
	* too long), and that's when this error message comes.
	*/
	public static TemplateException newLazilyGeneratedCollectionMustBeSequenceException(Expression blamed) {
	return new _MiscTemplateException(blamed,
	"The result is a listable value with lazy transformation(s) applied on it, but it's not " +
	"an FTL sequence (it's not a List-like value, but an Iterator-like value). The place doesn't " +
	"support such values due to technical limitations. So either pass it to a construct that supports " +
	"such values (like ", "<#list transformedListable as x>", "), or, if you know that you don't have " +
	"too many elements, use transformedListable?sequence to allow it to be treated as an FTL sequence.");
	}

	/**
	* @return "a" or "an" or "a(n)" (or "" for empty string) for an FTL type name
	*/
	static public String getAOrAn(String s) {
	if (s == null) return null;
	if (s.length() == 0) return "";

	char fc = Character.toLowerCase(s.charAt(0));
	if (fc == 'a' \|\| fc == 'e' \|\| fc == 'i') {
	return "an";
	} else if (fc == 'h') {
	String ls = s.toLowerCase();
	if (ls.startsWith("has") \|\| ls.startsWith("hi")) {
	return "a";
	} else if (ls.startsWith("ht")) {
	return "an";
	} else {
	return "a(n)";
	}
	} else if (fc == 'u' \|\| fc == 'o') {
	return "a(n)";
	} else {
	char sc = (s.length() > 1) ? s.charAt(1) : '\0';
	if (fc == 'x' && !(sc == 'a' \|\| sc == 'e' \|\| sc == 'i' \|\| sc == 'a' \|\| sc == 'o' \|\| sc == 'u')) {
	return "an";
	} else {
	return "a";
	}
	}
	}
	}