Testing Technology Glossary-L

Length. Maurice Halstead defined the length of a program to be

• Line mask. An EXDIFF statement that permits masking a line or group of lines.
• Linear histogram. A dynamically updated linear-style histogram showing accumulating C1 or S1 coverage for a selected module.
• Log file. An established or default SMARTS file where all test information is automatically accumulated.
• Logical branch. The set of statements in a module which are executed as the result of the evaluation of some predicate (conditional) within the module. The logical branch should be thought of as including the outcome of a conditional operation and the subsequent statement execution up to and including the computation of the value of the next predicate, but not including its evaluation in determining program flow.
• Logical units. A logical unit is a concept used for synchronization when differencing two files with the EXDIFF system. A logical unit may be a line of text, a page of text, a CAPBAK screen dump, or the keys (or responses) between marker records in a keysave file.
• Loop. A sequence of logical branches in a program that repeats at least one node. See Cycle.

(M,N)-cycle. An M-entry, N-exit cycle in a flow graph. A program is perfectly structured ("pure-structured") if it is composed of loops that involve only (1,1)-cycles. Most real-world programs contain many multi-exit cycles, however. Some studies show that over 99% of programs are non-pure-structured