FBASIC Library Decision Table Commands

[aafent]

the idea is to create a library with commands that are aiming to manipulate decision tables

FBASIC Decision Table Commands

This document defines the syntax and usage for manipulating decision tables in FBASIC using the custom command set.

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Commands

DTDIM

DTDIM name, otherwise_value, [factor1], [factor2], ..., [factorN]

Declares a decision table with one or more decision factors and a single result column.

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DTROW

DTROW name, resultValue, valueOfFactor1, valueOfFactor1, ..., valueOfFactorN

Adds a new row (rule) to an existing decision table, specifying factor values and the corresponding result.
number of factors should be the same as the DTDIM statement, otherwise an error will occured

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Search the decision table
There are two methods to extract result value from a decision table

1. Using the DTFIND statement (see below)
2. Using sequence of DTFACTOR to set the search factor values and then with DTGET statement (see below)

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DTFIND

DTFIND name, valueOfFactor1, ..., valueOfFactorN, resultVar

Queries the decision table with specified factor values. If a matching row is found, the result is stored in resultVar.

After each DTFIND command, the constant FOUND is automatically set:

• FOUND = -1 if a matching row was found (true).
• FOUND = 0 if no matching row was found (false).

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DTFACTOR name, valueOfFactor

DTFACTOR name, factorName, valueOfFactor

Set search value (valueOfFactor) for decision table name and factorName

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Utility Function

dtcount

dtcount(name)

Returns the number of rules (rows) currently defined in the decision table.

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Example Usage

REM Decision Table Example
REM
dtdim ScoreTable, 0, Salary, Score
dtrow ScoreTable, <100, 0
dtrow ScoreTable, <200, 1
dtrow ScoreTable, <699, 2
dtrow ScoreTable, 700:900, 10
' no for 901
dtrow ScoreTable, 902:2000, 20
dtrow ScoreTable, >=2001, 25

sdata Salary 1500, 300, 400, 210, 700, 950, 901

foreach Salary
    DTFIND ScoreTable, Score, score, [Salary.Item]
    print "For Salary " + Salary + " Score is " + score
EndForeach Salary

' Not found case
DTFIND ScoreTable, Score, score, 901
If FOUND Then
print "For Salary 901 Score is " + score
Else
print "For Salary 901 No matching rule found. Result:" + score

Halt

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Notes

• FOUND is a read-only constant representing the success of the last DTFIND.
• This command set follows FBASIC's conventions on Boolean values where -1 represents true and 0 represents false.
• Auxiliary commands for list, modify, and delete rows have been intentionally excluded for simplicity.

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[aafent]

Library is almost ready, soon will included in the upcoming Package.