Expressions

BaseExpression blocks are base-classes for a specific expression implementation. All four expression base-classes are derived from another base-class called ExpressionBlock E.g. ConstantDeclarationDefaultExpressionBlock is derived from ExpressionBlockEndedBySemicolon.

Generic BaseExpression Form

ExpressionBlock

Condensed definition of class ExpressionBlock:

@Export
class ExpressionBlock(Block):
  CHARACTER_TRANSLATION = {
    "=":    EqualOperator,
    "+":    PlusOperator,
    "-":    MinusOperator,
    "*":    MultiplyOperator,
    "/":    DivideOperator,
    "&":    ConcatOperator,
    "<":    LessThanOperator,
    ">":    GreaterThanOperator,
    ",":    DelimiterToken
    # ";":    EndToken
  }
  FUSED_CHARACTER_TRANSLATION = {
    "**":   PowerOperator,
    "/=":   UnequalOperator,
    "<=":   LessThanOrEqualOperator,
    ">=":   GreaterThanOrEqualOperator,
    "?=":   MatchingEqualOperator,
    "?/=":  MatchingUnequalOperator,
    "?<":   MatchingLessThanOperator,
    "?<=":  MatchingLessThanOrEqualOperator,
    "?>":   MatchingGreaterThanOperator,
    "?>=":  MatchingGreaterThanOrEqualOperator
    # "=>":   MapAssociationKeyword,
    # "<=>":  SignalAssociationKeyword
  }
  OPERATOR_TRANSLATIONS = {
    "or":    OrKeyword,
    "nor":   NorKeyword,
    "and":   AndKeyword,
    "nand":  NandKeyword,
    "xor":   XorKeyword,
    "xnor":  XnorKeyword,
    "sla":   SlaKeyword,
    "sll":   SllKeyword,
    "sra":   SraKeyword,
    "srl":   SrlKeyword,
    "not":   NotKeyword,
    "abs":   AbsKeyword
  }

Specific BaseExpression Forms

Expressions can be ended by:

) or a user-defined character

See ExpressionBlockEndedByCharORClosingRoundBracket

• ) or a user-defined keyword See ExpressionBlockEndedByKeywordORClosingRoundBracket

• to or downto keyword See ExpressionBlockEndedByKeywordOrToOrDownto

• ; See ExpressionBlockEndedBySemicolon

ExpressionBlockEndedByCharORClosingRoundBracket

This block is derived from ExpressionBlock. It implements an expression that is either ended by a closing round bracket (``)``) or a user-defined character. When this base-class is inherited, the user needs to overwrite:

EXIT_CHAR

The character causing this parser to exit and close this expression block.

EXIT_TOKEN

The token that is emitted as a replacement for the CharacterToken.

EXIT_BLOCK

The block that is generated when exiting the block.

Condensed definition of class ExpressionBlockEndedByCharORClosingRoundBracket:

@Export
class ExpressionBlockEndedByCharORClosingRoundBracket(ExpressionBlock):
  EXIT_CHAR  : str =   None
  EXIT_TOKEN : Token = None
  EXIT_BLOCK : Block = None

  @classmethod
  def stateBeforeExpression(cls, parserState: ParserState):

  @classmethod
  def stateExpression(cls, parserState: ParserState):

  @classmethod
  def stateWhitespace1(cls, parserState: ParserState):

ExpressionBlockEndedByKeywordORClosingRoundBracket

This block is derived from ExpressionBlock.

ExpressionBlockEndedByKeywordOrToOrDownto

This block is derived from ExpressionBlock.

ExpressionBlockEndedBySemicolon

This block is derived from ExpressionBlock.