Change IllegalArgumentException to ArgumentError.

lib/utf/utf32.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Decodes the UTF-32 bytes as an iterable. Thus, the consumer can only convert
  * as much of the input as needed. Determines the byte order from the BOM,
  * or uses big-endian as a default. This method always strips a leading BOM.
- * Set the replacementCharacter to null to throw an IllegalArgumentException
+ * Set the replacementCharacter to null to throw an ArgumentError
  * rather than replace the bad value.
  */
 IterableUtf32Decoder decodeUtf32AsIterable(List<int> bytes, [
     int offset = 0, int length,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
   return new IterableUtf32Decoder._(
       () => new Utf32BytesDecoder(bytes, offset, length, replacementCodepoint));
 }
 
 /**
  * Decodes the UTF-32BE bytes as an iterable. Thus, the consumer can only convert
  * as much of the input as needed. This method strips a leading BOM by default,
  * but can be overridden by setting the optional parameter [stripBom] to false.
- * Set the replacementCharacter to null to throw an IllegalArgumentException
+ * Set the replacementCharacter to null to throw an ArgumentError
  * rather than replace the bad value.
  */
 IterableUtf32Decoder decodeUtf32beAsIterable(List<int> bytes, [
     int offset = 0, int length, bool stripBom = true,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
   return new IterableUtf32Decoder._(
       () => new Utf32beBytesDecoder(bytes, offset, length, stripBom,
           replacementCodepoint));
 }
 
 /**
  * Decodes the UTF-32LE bytes as an iterable. Thus, the consumer can only convert
  * as much of the input as needed. This method strips a leading BOM by default,
  * but can be overridden by setting the optional parameter [stripBom] to false.
- * Set the replacementCharacter to null to throw an IllegalArgumentException
+ * Set the replacementCharacter to null to throw an ArgumentError
  * rather than replace the bad value.
  */
 IterableUtf32Decoder decodeUtf32leAsIterable(List<int> bytes, [
     int offset = 0, int length, bool stripBom = true,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
   return new IterableUtf32Decoder._(
       () => new Utf32leBytesDecoder(bytes, offset, length, stripBom,
           replacementCodepoint));
 }
 
 /**
  * Produce a String from a sequence of UTF-32 encoded bytes. The parameters
  * allow an offset into a list of bytes (as int), limiting the length of the
  * values be decoded and the ability of override the default Unicode
  * replacement character. Set the replacementCharacter to null to throw an
- * IllegalArgumentException rather than replace the bad value.
+ * ArgumentError rather than replace the bad value.
  */
 String decodeUtf32(List<int> bytes, [int offset = 0, int length,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) {
   return codepointsToString((new Utf32BytesDecoder(bytes, offset, length,
       replacementCodepoint)).decodeRest());
 }
 /**
  * Produce a String from a sequence of UTF-32BE encoded bytes. The parameters
  * allow an offset into a list of bytes (as int), limiting the length of the
  * values be decoded and the ability of override the default Unicode
  * replacement character. Set the replacementCharacter to null to throw an
- * IllegalArgumentException rather than replace the bad value.
+ * ArgumentError rather than replace the bad value.
  */
 String decodeUtf32be(
     List<int> bytes, [int offset = 0, int length, bool stripBom = true,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) =>
   codepointsToString((new Utf32beBytesDecoder(bytes, offset, length, stripBom,
       replacementCodepoint)).decodeRest());
 
 /**
  * Produce a String from a sequence of UTF-32LE encoded bytes. The parameters
  * allow an offset into a list of bytes (as int), limiting the length of the
  * values be decoded and the ability of override the default Unicode
  * replacement character. Set the replacementCharacter to null to throw an
- * IllegalArgumentException rather than replace the bad value.
+ * ArgumentError rather than replace the bad value.
  */
 String decodeUtf32le(
     List<int> bytes, [int offset = 0, int length, bool stripBom = true,
     int replacementCodepoint = UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) =>
     codepointsToString((new Utf32leBytesDecoder(bytes, offset, length, stripBom,
         replacementCodepoint)).decodeRest());
 
 /**
  * Produce a list of UTF-32 encoded bytes. This method prefixes the resulting
  * bytes with a big-endian byte-order-marker.
@@ skipping 135 matching lines @@
   }
 
   bool hasNext() => utf32EncodedBytesIterator.hasNext();
 
   int next() {
     if (utf32EncodedBytesIterator.remaining < 4) {
       utf32EncodedBytesIterator.skip(utf32EncodedBytesIterator.remaining);
       if (replacementCodepoint != null) {
           return replacementCodepoint;
       } else {
-        throw new IllegalArgumentException(
+        throw new ArgumentError(
             "Invalid UTF32 at ${utf32EncodedBytesIterator.position}");
       }
     } else {
       int codepoint = decode();
       if (_validCodepoint(codepoint)) {
         return codepoint;
       } else if (replacementCodepoint != null) {
           return replacementCodepoint;
       } else {
-        throw new IllegalArgumentException(
+        throw new ArgumentError(
             "Invalid UTF32 at ${utf32EncodedBytesIterator.position}");
       }
     }
   }
 
   int get position => utf32EncodedBytesIterator.position ~/ 4;
 
   void backup([int by = 1]) {
     utf32EncodedBytesIterator.backup(4 * by);
   }
@@ skipping 53 matching lines @@
     value += (utf32EncodedBytesIterator.next() << 24);
     return value;
   }
 }
 
 bool _validCodepoint(int codepoint) {
   return (codepoint >= 0 && codepoint < UNICODE_UTF16_RESERVED_LO) ||
       (codepoint > UNICODE_UTF16_RESERVED_HI &&
       codepoint < UNICODE_VALID_RANGE_MAX);
 }