Package adams.flow.control

Class Block

  • All Implemented Interfaces:
    AdditionalInformationHandler, CleanUpHandler, Destroyable, GlobalInfoSupporter, LoggingLevelHandler, LoggingSupporter, OptionHandler, QuickInfoSupporter, ShallowCopySupporter<Actor>, SizeOfHandler, Stoppable, StoppableWithFeedback, VariablesInspectionHandler, VariableChangeListener, BooleanConditionSupporter, Actor, ControlActor, ErrorHandler, InputConsumer, OutputProducer, GrammarSupplier, Serializable, Comparable
    public class Block
extends AbstractTransformer
implements ControlActor, GrammarSupplier, BooleanConditionSupporter
    Blocks the propagation of tokens if the condition evaluates to 'true', therefore acts like the 'continue' control statement.
    In case of integer or double tokens that arrive at the input, these can be accessed in the expression via 'X'.

    The following grammar is used for evaluating the boolean expressions (depends on the selected condition):

    expr_list ::= '=' expr_list expr_part | expr_part ;
    expr_part ::= expr ;

    expr ::= ( expr )

    # data types
    | number
    | string
    | boolean
    | date

    # constants
    | true
    | false
    | pi
    | e
    | now()
    | today()

    # negating numeric value
    | -expr

    # comparisons
    | expr < expr
    | expr <= expr
    | expr > expr
    | expr >= expr
    | expr = expr
    | expr != expr (or: expr <> expr)

    # boolean operations
    | ! expr (or: not expr)
    | expr & expr (or: expr and expr)
    | expr | expr (or: expr or expr)
    | if[else] ( expr , expr (if true) , expr (if false) )
    | ifmissing ( variable , expr (default value if variable is missing) )

    # arithmetics
    | expr + expr
    | expr - expr
    | expr * expr
    | expr / expr
    | expr ^ expr (power of)
    | expr % expr (modulo)
    ;

    # numeric functions
    | abs ( expr )
    | sqrt ( expr )
    | log ( expr )
    | exp ( expr )
    | sin ( expr )
    | cos ( expr )
    | tan ( expr )
    | rint ( expr )
    | floor ( expr )
    | pow[er] ( expr , expr )
    | ceil ( expr )
    | year ( expr )
    | month ( expr )
    | day ( expr )
    | hour ( expr )
    | minute ( expr )
    | second ( expr )
    | weekday ( expr )
    | weeknum ( expr )

    # string functions
    | substr ( expr , start [, end] )
    | left ( expr , len )
    | mid ( expr , start , len )
    | right ( expr , len )
    | rept ( expr , count )
    | concatenate ( expr1 , expr2 [, expr3-5] )
    | lower[case] ( expr )
    | upper[case] ( expr )
    | trim ( expr )
    | matches ( expr , regexp )
    | trim ( expr )
    | len[gth] ( str )
    | find ( search , expr [, pos] )
    | replace ( str , pos , len , newstr )
    | substitute ( str , find , replace [, occurrences] )
    ;

    Notes:
    - Variables are either all upper case letters (e.g., "ABC") or any character apart from "]" enclosed by "[" and "]" (e.g., "[Hello World]").
    - 'start' and 'end' for function 'substr' are indices that start at 1.
    - Index 'end' for function 'substr' is excluded (like Java's 'String.substring(int,int)' method)
    - Line comments start with '#'
    - Semi-colons (';') or commas (',') can be used as separator in the formulas,
    e.g., 'pow(2,2)' is equivalent to 'pow(2;2)'
    - dates have to be of format 'yyyy-MM-dd' or 'yyyy-MM-dd HH:mm:ss'
    - times have to be of format 'HH:mm:ss' or 'yyyy-MM-dd HH:mm:ss'
    - the characters in square brackets in function names are optional:
    e.g. 'len("abc")' is the same as 'length("abc")'

    A lot of the functions have been modeled after LibreOffice:
    https://help.libreoffice.org/Calc/Functions_by_Category


    Input/output:
    - accepts:
       adams.flow.core.Unknown
    - generates:
       adams.flow.core.Unknown


    -logging-level <OFF|SEVERE|WARNING|INFO|CONFIG|FINE|FINER|FINEST> (property: loggingLevel)
    The logging level for outputting errors and debugging output.
    default: WARNING
 
    -name <java.lang.String> (property: name)
    The name of the actor.
    default: Continue
 
    -annotation <adams.core.base.BaseText> (property: annotations)
    The annotations to attach to this actor.
    default: 
 
    -skip <boolean> (property: skip)
    If set to true, transformation is skipped and the input token is just forwarded 
    as it is.
    default: false
 
    -stop-flow-on-error <boolean> (property: stopFlowOnError)
    If set to true, the flow gets stopped in case this actor encounters an error;
     useful for critical actors.
    default: false
 
    -condition <adams.flow.condition.bool.BooleanCondition> (property: condition)
    The condition that determines whether to drop the token (ie continue) (evaluates 
    to 'true') or not (evaluates to 'false').
    default: adams.flow.condition.bool.Expression -expression false
    Author:
    fracpete (fracpete at waikato dot ac dot nz)
    See Also:
    Serialized Form