Guard

Guard or guards may refer to:

Professional occupations

Governmental and military

Sports

Hilt

The hilt (rarely called the haft) of a sword is its handle, consisting of a guard, grip and pommel. Also meaning To the limit; completely: played the role to the hilt. Idiom: to the hilt. The guard may contain a crossguard or quillons. A ricasso may also be present, but this is rarely the case. A tassel or sword knot may be attached to the guard or pommel.

Pommel

The pommel (Anglo-Norman pomel "little apple") is an enlarged fitting at the top of the handle. They were originally developed to prevent the sword slipping from the hand. From around the 11th century in Europe they became heavy enough to be a counterweight to the blade. This gave the sword a point of balance not too far from the hilt allowing a more fluid fighting style. Depending on sword design and swordsmanship style, the pommel may also be used to strike the opponent (e.g., using the Mordhau technique).

Pommels have appeared in a wide variety of shapes, including oblate spheroids, crescents, disks, wheels, and animal or bird heads. They are often engraved or inlayed with various designs and occasionally gilt and mounted with jewels. Ewart Oakeshott introduced a system of classification of medieval pommel forms in his The Sword in the Age of Chivalry (1964) to stand alongside his blade typology. Oakeshott pommel types are enumerated with capital letters A–Z, with subtypes indicated by numerals.

Guard (computer science)

In computer programming, a guard is a boolean expression that must evaluate to true if the program execution is to continue in the branch in question.

Regardless of which programming language is used, guard code is a check of integrity preconditions used to avoid errors during execution. A typical example is checking that a reference about to be processed be not null, which avoids null-pointer failures.

The term is used with specific meaning a.o. in Haskell, Clean, Erlang, occam, Promela, OCaml and Scala programming languages. In Mathematica, guards are called constraints. Guards are the fundamental concept in Guarded Command Language, a language in formal methods. Guards can be used to augment pattern matching with the possibility to skip a pattern even if the structure matches. Boolean expressions in conditional statements usually also fit this definition of a guard although they are called conditions.

In the following Haskell example, the guards occur between each pair of "|" and "=":