Merge pull request aeron-io#278 from tfgm-bud/master

[python] Fixes and improvements to enum handling

Author: tmontgomery

main/java/uk/co/real_logic/sbe/generation/python/PythonGenerator.java

@@ -314,12 +314,12 @@ private CharSequence generateVarData(final List<Token> tokens)
  " def get%1$s(self):\n" +
  " sizeOfLengthField = %3$d\n" +
  " lengthPosition = self.getPosition()\n" +
- " dataLength = struct.unpack_from('%5$s', self.buffer_, lengthPosition[0])[0]\n" +
- " self.setPosition(lengthPosition[0] + sizeOfLengthField)\n" +
+ " dataLength = struct.unpack_from('%5$s', self.buffer_, lengthPosition)[0]\n" +
+ " self.setPosition(lengthPosition + sizeOfLengthField)\n" +
  " pos = self.getPosition()\n" +
- " fmt = '" + byteOrder + "'+str(dataLength)+'c'\n" +
- " data = struct.unpack_from(fmt, self.buffer_, lengthPosition[0])\n" +
- " self.setPosition(pos[0] + dataLength)\n" +
+ " fmt = '" + byteOrder + "' + str(dataLength) + 's'\n" +
+ " data = struct.unpack_from(fmt, self.buffer_, pos)[0]\n" +
+ " self.setPosition(pos + dataLength)\n" +
  " return data\n\n",
  propertyName,
  generateArrayFieldNotPresentCondition(token.version(), BASE_INDENT),
@@ -332,13 +332,12 @@ private CharSequence generateVarData(final List<Token> tokens)
  " def set%1$s(self, buffer):\n" +
  " sizeOfLengthField = %2$d\n" +
  " lengthPosition = self.getPosition()\n" +
- " struct.pack_into('%3$s', self.buffer_, lengthPosition[0], len(buffer))\n" +
- " self.setPosition(lengthPosition[0] + sizeOfLengthField)\n" +
+ " struct.pack_into('%3$s', self.buffer_, lengthPosition, len(buffer))\n" +
+ " self.setPosition(lengthPosition + sizeOfLengthField)\n" +
  " pos = self.getPosition()\n" +
- " fmt = '" + byteOrder + "c'\n" +
- " for i in range(0,len(buffer)):\n" +
- " struct.pack_into(fmt, self.buffer_, lengthPosition[0]+i, buffer[i])\n" +
- " self.setPosition(pos[0] + len(buffer))\n\n",
+ " fmt = '" + byteOrder + "' + str(len(buffer)) + 's'\n" +
+ " struct.pack_into(fmt, self.buffer_, pos, buffer)\n" +
+ " self.setPosition(pos + len(buffer))\n\n",
  propertyName,
  sizeOfLengthField,
  lengthPythonType,
@@ -394,7 +393,7 @@ private void generateVarDataDescriptors(
 
  sb.append(String.format(
  " def %1$sLength(self):\n" +
- " return struct.unpack_from('%4$s', self.buffer_, position())[0]\n\n",
+ " return struct.unpack_from('%4$s', self.buffer_, getPosition())[0]\n\n",
  formatPropertyName(propertyName),
  generateArrayFieldNotPresentCondition(token.version(), BASE_INDENT),
  formatByteOrderEncoding(lengthToken.encoding().byteOrder(), lengthToken.encoding().primitiveType()),
@@ -432,9 +431,9 @@ private void generateEnum(final List<Token> tokens) throws IOException
  try (final Writer out = outputManager.createOutput(enumName))
  {
  out.append(generateFileHeader(ir.applicableNamespace().replace('.', '_'), null));
- out.append(generateEnumDeclaration(enumName));
+ out.append(generateClassDeclaration(enumName));
  out.append(generateEnumValues(tokens.subList(1, tokens.size() - 1), enumToken));
- out.append(generateEnumLookupMethod(tokens.subList(1, tokens.size() - 1), enumToken));
+ out.append(generateEnumMethods(enumName));
  }
  }
 
@@ -514,55 +513,65 @@ private CharSequence generateEnumValues(final List<Token> tokens, final Token en
  final StringBuilder sb = new StringBuilder();
  final Encoding encoding = encodingToken.encoding();
 
- sb.append(" class Value:\n");
+ for (final Token token : tokens)
+ {
+ if (encoding.primitiveType() == PrimitiveType.CHAR)
+ {
+ final char constVal = (char) token.encoding().constValue().longValue();
+ sb.append(" ").append(token.name()).append(" = '").append(constVal).append("'\n");
+ }
+ else
+ {
+ final CharSequence constVal = generateLiteral(
+ token.encoding().primitiveType(), token.encoding().constValue().toString());
+ sb.append(" ").append(token.name()).append(" = ").append(constVal).append("\n");
+ }
+ }
+
+ // generate the null value
 
+ if (encoding.primitiveType() == PrimitiveType.CHAR)
+ {
+ sb.append(" NULL_VALUE = '\\0'");
+ }
+ else
+ {
+ sb.append(String.format(
+ " NULL_VALUE = %1$s",
+ generateLiteral(encoding.primitiveType(), encoding.applicableNullValue().toString())
+ ));
+ }
+ sb.append("\n\n");
+
+ sb.append(" VALID_VALUES = {\n");
  for (final Token token : tokens)
  {
- final CharSequence constVal = generateLiteral(
- token.encoding().primitiveType(), token.encoding().constValue().toString());
- sb.append(" ").append(token.name()).append(" = ").append(constVal).append("\n");
+ sb.append(" ").append(token.name()).append(",\n");
  }
+ sb.append(" NULL_VALUE,\n }\n\n");
 
- sb.append(String.format(
- " NULL_VALUE = %1$s",
- generateLiteral(encoding.primitiveType(), encoding.applicableNullValue().toString())
- ));
+ sb.append(" AS_TEXT = {\n");
 
- sb.append("\n\n");
+ for (final Token token : tokens)
+ {
+ sb.append(" ").append(token.name()).append(" : '").append(token.name()).append("',\n");
+ }
+ sb.append(" NULL_VALUE : 'NULL_VALUE',\n }\n\n");
 
  return sb;
  }
 
- private CharSequence generateEnumLookupMethod(final List<Token> tokens, final Token encodingToken)
+ private CharSequence generateEnumMethods(final String name)
  {
- final String enumName = formatClassName(encodingToken.name());
  final StringBuilder sb = new StringBuilder();
 
- sb.append(
- " @staticmethod\n" +
- " def get(value):\n" +
- " values = {\n");
-
- for (final Token token : tokens)
- {
- sb.append(String.format(
- " %1$s : %3$s.Value.%2$s,\n",
- token.encoding().constValue().toString(),
- token.name(),
- enumName)
- );
- }
-
- sb.append(String.format(
- " %1$s : %2$s.Value.NULL_VALUE\n" +
- " }\n" +
- " if type(value) is int:\n" +
- " return values[value]\n" +
- " else:\n" +
- " return values[ord(value)]\n",
- encodingToken.encoding().applicableNullValue().toString(),
- enumName
- ));
+ sb.append(" def __init__(self, value):\n");
+ sb.append(" self.value = value\n");
+ sb.append(" if self.value not in ").append(name).append(".VALID_VALUES:\n");
+ sb.append(" raise ValueError('Invalid value for ").append(name).append(": {}'.format(value))\n");
+ sb.append("\n");
+ sb.append(" def __str__(self):\n");
+ sb.append(" return ").append(name).append(".AS_TEXT[self.value]\n");
 
  return sb;
  }
@@ -624,11 +633,6 @@ private CharSequence generateClassDeclaration(final String name)
  return "class " + name + ":\n";
  }
 
- private CharSequence generateEnumDeclaration(final String name)
- {
- return "class " + name + ":\n";
- }
-
  private CharSequence generatePrimitivePropertyEncodings(
  final String containingClassName, final List<Token> tokens, final String indent)
  {
@@ -784,12 +788,12 @@ private CharSequence generateArrayProperty(
  ));
 
  sb.append(String.format(
- indent + " def set%1$s(self, index, value):\n" +
+ indent + " def set%2$s(self, index, value):\n" +
  indent + " if index < 0 or index >= %3$d:\n" +
- indent + " raise Exception('index out of range for %1$s')\n" +
- indent + " struct.pack_into('%2$s', self.buffer_, self.offset_ + %4$d + (index * %5$d), value)\n",
- propertyName,
- toUpperFirstChar(pythonTypeName),
+ indent + " raise Exception('index out of range for %2$s')\n" +
+ indent + " struct.pack_into('%1$s', self.buffer_, self.offset_ + %4$d + (index * %5$d), value)\n",
+ pythonTypeName,
+ toUpperFirstChar(propertyName),
  token.arrayLength(),
  offset,
  token.encoding().primitiveType().size(),
@@ -928,15 +932,15 @@ private CharSequence generateMessageFlyweightCode(final Token token)
  " return self\n\n" +
 
  " def getPosition(self):\n" +
- " return self.position_\n\n" +
+ " return self.position_[0]\n\n" +
 
  " def setPosition(self, position):\n" +
  " if position > self.bufferLength_:\n" +
  " raise Exception('buffer too short')\n" +
  " self.position_[0] = position\n\n" +
 
  " def encodedLength(self):\n" +
- " return self.position() - self.offset_\n\n" +
+ " return self.getPosition() - self.offset_\n\n" +
 
  " def buffer(self):\n" +
  " return self.buffer_\n\n" +
@@ -1054,7 +1058,7 @@ private CharSequence generateEnumProperty(
  sb.append(String.format(
  "\n" +
  indent + " def get%2$s(self):\n" +
- indent + " return %1$s.%1$s.get(struct.unpack_from( '%5$s', self.buffer_, self.offset_ + %6$d)[0])\n\n",
+ indent + " return %1$s.%1$s(struct.unpack_from( '%5$s', self.buffer_, self.offset_ + %6$d)[0])\n\n",
  enumName,
  toUpperFirstChar(propertyName),
  generateEnumFieldNotPresentCondition(token.version(), enumName, indent),