Eager evaluation
Any evaluation strategy where evaluation of some or all function arguments is started before their value is required. A typical example is call-by-value, where all arguments are passed evaluated. The opposite of eager evaluation is call-by-need where evaluation of an argument is only started when it is required.
The term “speculative evaluation” is very close in meaning to eager evaluation but is applied mostly to parallel architectures whereas eager evaluation is used of both sequential and parallel evaluators.
Eager evaluation does not specify exactly when argument evaluation takes place – it might be done fully speculatively (all redexes in the program reduced in parallel) or may be done by the caller just before the function is entered.
The term “eager evaluation” was invented by Carl Hewitt and Henry Baker and used in their paper [“The Incremental Garbage Collection of Processes”, Sigplan Notices, Aug 1977. (ftp://ftp.netcom.com/pub/hb/hbaker/Futures.html)]. It was named after their “eager beaver” evaluator.
See also conservative evaluation, lenient evaluation, strict evaluation.
(1994-12-22)
Read Also:
- Eagerness
[ee-ger] /ˈi gər/ adjective 1. keen or ardent in desire or feeling; impatiently longing: I am eager for news about them. He is eager to sing. 2. characterized by or revealing great earnestness: an eager look. 3. Obsolete. keen; sharp; biting. /ˈiːɡə/ adjective 1. (postpositive; often foll by to or for) impatiently desirous (of); anxious […]
- Eagerly
[ee-ger] /ˈi gər/ adjective 1. keen or ardent in desire or feeling; impatiently longing: I am eager for news about them. He is eager to sing. 2. characterized by or revealing great earnestness: an eager look. 3. Obsolete. keen; sharp; biting. /ˈiːɡə/ adjective 1. (postpositive; often foll by to or for) impatiently desirous (of); anxious […]
- Eagle
[ee-guh l] /ˈi gəl/ noun 1. any of several large, soaring birds of prey belonging to the hawk family Accipitridae, noted for their size, strength, and powers of flight and vision: formerly widespread in North America, eagles are mostly confined to Alaska and a few isolated populations. Compare , . 2. a figure or representation […]
- Eagle-eye
noun 1. unusually sharp visual powers; keen ability to watch or observe. 2. a person who has sharp vision or who maintains a keen watchfulness. 3. alert watchfulness. noun Unusually keen sight; also, keen intellectual vision. For example, Antiques dealers have an eagle eye for valuable objects, or A good manager has an eagle eye […]
- Eagle-eyed
[ee-guh l-ahyd] /ˈi gəlˌaɪd/ adjective 1. having keen vision. adjective 1. having keen or piercing eyesight adjective