Overview
The RHS Expressions are expressions on the Right-Hand Side of the assignment symbol or assignment operator which are used to specify, retrieve and/or calculate values. Following rules apply:
- Constant values like numbers (for numeral values) and text (for string and boolean values)
- Sets,
- Variables,
- For variables, individual Member variables using array subscripts and member names may be referenced:
- Table references,
- For tables, either single cells or a combination of mulitple cells (including whole rows and columns) may be specified:
- Function calls to functions which return values of any type,
- Any calcualations:
- With unary operators, binary operators and/or parentheses:
- Parentheses are useful to overrule operator precedence.
- Ad-hoc operations are allowed on specified variables and table entries. Example: a[]++ = 5;. The 5 will be incremented by 1 to 6 after the assignment.
RHS Expressions are applicable in following cases:
- On the right-hand-side of all Assignments,
- Input Parameters in procedure and function calls
- Variable names, example: ('Category '+name[])[]
- Parentheses are mandatory if the variable specified as a LHS expression, e.g. (name[])[] = Hello;
- Otherwise, parentheses are mandatory if any calculations are applied in order to encompass the whole result, e.g. ('My '+name[])[] = Nick; where it is ensured that 'My ' is part of the variable name to use.
The following are not allowed in RHS expressions:
- Applying ad-hoc operations on calculated expressions and function calls, e.g. (a[]+4)++.
- Applying them on the left-hand-side of assignment symbols, as I/O parameters in function and procedure calls, and transactions
Note: Whenever the term Expression is referred without indications on left/right-hand sides, then the right-hand-side is assumed.
Examples
echo(RHS Examples with variables);
a[] = 10;
a[name] = 'My Name';
a[four] = (a[] - 2)/2;
a[colors] = { red, yellow, green, blue };
a[nine] = sqrt(81);
see(a[]);
echo(RHS Examples with a table);
table initialize ( List, {{Name, Score}, { Amy, 10}, { Bea, 20}, {Claus, 30}} );
echo( [List: Name, 2] ); // Bea
echo( [List: Name, Amy, Score] ); // Amy's Score: 10
echo( [List: Name, ..] ); // All names in a set
RHS Examples with variables
a[] 10 "10" (numeral,full access)
colors 4 elements: (set,full access)
red (softquoted string)
yellow (softquoted string)
green (softquoted string)
blue (softquoted string)
four 4 (plain numeral,full access)
name My Name (softquoted string,full access)
nine 9 (plain numeral,full access)
RHS Examples with a table
Bea
10
{'Amy','Bea','Claus'}