Concepts¶

How DPM-XL rules are evaluated. These pages explain the semantics; the language reference lists every construct.

• Records and keys: selections yield keyed records; operators join them.
• Null logic: defaults, null propagation, three-valued logic and errors confined to their record.
• Interval arithmetic: reported precision as intervals, and the gap in explanations.
• Preconditions and results: the five statuses and what a result holds.
• Statements and assignments: scripts with := and <-.
• Sets: set literals, parameters, operators and in.
• Aggregates and analytic functions: group by, rank and windows.
• Time: dates, time_shift and annualise.
• Parameters, operations and table groups: everything a rule reads besides cells.

Sources and choices¶

These semantics follow the EBA DPM-XL language specification v0.9 (operators and data model documents) and the Eurofiling interval arithmetic functions. Where the specification is ambiguous or contradicts itself (sum of no records, count over nulls, key-name aliases, the radius formulas for products and quotients), dpm-xl makes the choice that avoids false failures, and says so on the page concerned.