Package adams.flow.condition.bool

Class Expression

  • All Implemented Interfaces:
    Destroyable, GlobalInfoSupporter, LoggingLevelHandler, LoggingSupporter, OptionHandler, QuickInfoSupporter, ShallowCopySupporter<BooleanCondition>, SizeOfHandler, Stoppable, BooleanCondition, GrammarSupplier, Serializable
    public class Expression
extends AbstractExpression
    Evaluates to 'true' if the expression evaluates to 'true'.
    In case of java.lang.Number tokens that arrive at the input, these can be accessed in the expression via 'X'; string tokens can be accessed via expression '"X"' (surrounding double quotes are required).
    If the incoming token is either a Report or a ReportHandler, the contents of the report get added as values as well (boolean, numeric or string) and you can access them via their name instead of 'X'.

    The following grammar is used for evaluating the boolean expressions:

    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) )
    | isNaN ( expr )

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

    # numeric functions
    | abs ( expr )
    | sqrt ( expr )
    | cbrt ( expr )
    | log ( expr )
    | log10 ( expr )
    | exp ( expr )
    | sin ( expr )
    | sinh ( expr )
    | cos ( expr )
    | cosh ( expr )
    | tan ( expr )
    | tanh ( expr )
    | atan ( expr )
    | atan2 ( exprY , exprX )
    | hypot ( exprX , exprY )
    | signum ( expr )
    | rint ( expr )
    | floor ( expr )
    | pow[er] ( expr , expr )
    | ceil ( expr )
    | min ( expr1 , expr2 )
    | max ( expr1 , expr2 )
    | 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] )

    # array functions
    | len[gth] ( array )
    | get ( array , index )
    ;

    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' for function 'get' starts 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

    Additional functions:
    - env(String): String
       First argument is the name of the environment variable to retrieve.
       The result is the value of the environment variable.

    Additional procedures:
    - println(...)
       One or more arguments are printed as comma-separated list to stdout.
       If no argument is provided, a simple line feed is output.


    -logging-level <OFF|SEVERE|WARNING|INFO|CONFIG|FINE|FINER|FINEST> (property: loggingLevel)
    The logging level for outputting errors and debugging output.
    default: WARNING
 
    -expression <adams.parser.BooleanExpressionText> (property: expression)
    The expression to evaluate; expressions that consists solely of a variable 
    (eg '@{blah}') get automatically wrapped in parentheses, since the expression 
    string gets interpreted as attached variable instead.
    default: true
    Author:
    fracpete (fracpete at waikato dot ac dot nz)
    See Also:
    Serialized Form

    • Constructor Detail

      • Expression

        public Expression()
        Default constructor.

      • Expression

        public Expression​(BooleanExpressionText expression)
        Initializes with the specified expression.
        Parameters:
        expression - the expression to use

      • Expression

        public Expression​(String expression)
        Initializes with the specified expression.
        Parameters:
        expression - the expression to use