Oninit® BLT — printers

A complete Informix 4GL CRUD application driven through BLT: 4GL source (printers.4gl), screen-form spec (printers.per), and DDL (printers.sql) on the input side; the generated functional specification on the output side. The application maintains a printers table with id, name, description, command, destination, and active columns. BLT recovers what each user-facing function does to that table and emits the result as evidence-cited findings with explicit confidence levels.

Source — printers.4gl (excerpt)

DATABASE fms

DEFINE m_current  RECORD
    id      INTEGER,
    name    CHAR(20),
    desc    CHAR(60),
    cmd     CHAR(20),
    dest    CHAR(1),
    active  CHAR(1)
END RECORD

MAIN
    DEFER INTERRUPT
    DEFER QUIT
    OPTIONS
        INPUT WRAP,
        PROMPT LINE LAST,
        MESSAGE LINE LAST,
        NEXT KEY CONTROL-F,
        PREVIOUS KEY CONTROL-B
    LET int_flag = 0
    CALL main_code()
    EXIT PROGRAM
END MAIN

FUNCTION main_code()
    OPEN FORM autoform FROM "printers"
    DISPLAY FORM autoform
    MENU "Action"
        COMMAND "Query"  "Find a record"     CALL query_det()
        COMMAND "Add"    "Add a record"      CALL add_det()
        COMMAND "Update" "Update a record"   CALL update_det()
        COMMAND "Delete" "Delete a record"   CALL delete_det()
        COMMAND KEY ("E") "Exit" "Exit this program" EXIT MENU
    END MENU
END FUNCTION

FUNCTION add_det()
    CALL init_buf()
    INPUT BY NAME
        m_current.id, m_current.name, m_current.desc,
        m_current.cmd, m_current.dest, m_current.active
        AFTER INPUT
            INSERT INTO printers (
                id, name, desc, cmd, dest, active
            ) VALUES (
                m_current.id, m_current.name, m_current.desc,
                m_current.cmd, m_current.dest, m_current.active
            )
            IF SQLCA.SQLCODE != 0 THEN
                ERROR "ERROR: Row not added: ", SQLCA.SQLCODE
            ELSE
                MESSAGE "Row added"
            END IF
    END INPUT
END FUNCTION

Form spec — printers.per

database fms@dmi_on
screen size 24 by 80
{
id                  [f000       ]
name                [f001                ]
desc                [f002                          ]
                    [f003                          ]
cmd                 [f004                ]
dest                [a]
active              [b]
}
end
tables
printers
attributes
f000 = formonly.id type int;
f001 = printers.name;
f002 = printers.desc[1,30];
f003 = printers.desc[31,60];
f004 = printers.cmd;
a = printers.dest;
b = printers.active;
end

DDL — printers.sql

create table "informix".printers (
    id      serial      not null,
    name    char(20)    not null,
    desc    char(60)    not null,
    cmd     char(20)    not null,
    dest    char(1),
    active  char(1),
    check (active IN ('Y', 'N')),
    check (dest IN ('E', 'S', 'P', 'D', 'T'))
        constraint "informix".printers_dest
);

create unique index "informix".iu_printers
    on "informix".printers (id) using btree;

What BLT recovers

Run against the three inputs above, BLT produces a deterministic behavioural specification covering the printers application's user-facing behaviour. Every finding is cited to the underlying source artefact and carries an explicit confidence level so a reviewer can trust the spec or drill into the citation.

The same source produces a byte-identical specification on every run — determinism is a hard property of the output, not a best-effort one.