interpreter

[in-tur-pri-ter] /ɪnˈtɜr prɪ tər/
noun
1.
a person who interprets.
2.
a person who provides an oral translation between speakers who speak different languages.
3.
Computers.
  1. hardware or software that transforms one statement at a time of a program written in a high-level language into a sequence of machine actions and executes the statement immediately before going on to transform the next statement.
    Compare compiler (def 2).
  2. an electromechanical device that reads the patterns of holes in punched cards and prints the same data on the cards, so that they can be read more conveniently by people.
Origin
1350-1400; Middle English interpretour < Anglo-French; see interpret, -er2
Examples from the web for interpreter
  • Officers in the case could not be reached today to ask whether an interpreter had been requested.
  • For instance someone told me to talk to the student not the interpreter.
  • There was always a need for an interpreter of his findings.
  • He and my interpreter pick up telephones on either side of the window.
  • Jimenez, three more soldiers and the interpreter were not.
  • Many other firms are also jostling to become the main interpreter of corporate data.
  • Lewis gave a speech, but they had no interpreter and it had to be curtailed.
  • By the way, words are only as meaningful as the interpreter desires them to be.
British Dictionary definitions for interpreter

interpreter

/ɪnˈtɜːprɪtə/
noun
1.
a person who translates orally from one language into another
2.
a person who interprets the work of others
3.
(computing)
  1. a program that translates a second program to machine code one statement at a time and causes the execution of the resulting code as soon as the translation is completed
  2. a machine that interprets the holes in a punched card and prints the corresponding characters on that card
Derived Forms
interpretership, noun
interpretress, noun:feminine
Word Origin and History for interpreter
n.

"one who translates spoken languages; a translator of written texts," late 14c., from Old French interpreteor, from Late Latin interpretatorem, agent noun from interpretari (see interpret).

interpreter in Technology
programming
A program which executes other programs. This is in contrast to a compiler which does not execute its input program (the "source code") but translates it into executable "machine code" (also called "object code") which is output to a file for later execution. It may be possible to execute the same source code either directly by an interpreter or by compiling it and then executing the machine code produced.
It takes longer to run a program under an interpreter than to run the compiled code but it can take less time to interpret it than the total required to compile and run it. This is especially important when prototyping and testing code when an edit-interpret-debug cycle can often be much shorter than an edit-compile-run-debug cycle.
Interpreting code is slower than running the compiled code because the interpreter must analyse each statement in the program each time it is executed and then perform the desired action whereas the compiled code just performs the action. This run-time analysis is known as "interpretive overhead". Access to variables is also slower in an interpreter because the mapping of identifiers to storage locations must be done repeatedly at run time rather than at compile time.
There are various compromises between the development speed when using an interpreter and the execution speed when using a compiler. Some systems (e.g. some Lisps) allow interpreted and compiled code to call each other and to share variables. This means that once a routine has been tested and debugged under the interpreter it can be compiled and thus benefit from faster execution while other routines are being developed. Many interpreters do not execute the source code as it stands but convert it into some more compact internal form. For example, some BASIC interpreters replace keywords with single byte tokens which can be used to index into a jump table. An interpreter might well use the same lexical analyser and parser as the compiler and then interpret the resulting abstract syntax tree.
There is thus a spectrum of possibilities between interpreting and compiling, depending on the amount of analysis performed before the program is executed. For example Emacs Lisp is compiled to "byte-code" which is a highly compressed and optimised representation of the Lisp source but is not machine code (and therefore not tied to any particular hardware). This "compiled" code is then executed (interpreted) by a byte code interpreter (itself written in C). The compiled code in this case is machine code for a virtual machine which is implemented not in hardware but in the byte-code interpreter.
See also partial evaluation.
(1995-01-30)