usr/man/cat1/fp.0



FP(1)               UNIX Programmer's Manual                FP(1)


N\bNA\bAM\bME\bE
     fp -  Functional Programming language compiler/interpreter

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
     f\bfp\bp

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
     _\bF_\bp is an interpreter/compiler that implements the applica-
     tive language proposed by John Backus.  It is written in
     F\bFR\bRA\bAN\bNZ\bZ L\bLI\bIS\bSP\bP.

     In a  functional programming language intent is expressed in
     a mathematical style devoid of assignment statements and
     variables.  Functions compute by value only; there are no
     side-effects since  the result of a computation depends
     solely on the inputs.

     _\bF_\bp "programs" consist of _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\ba_\bl _\be_\bx_\bp_\br_\be_\bs_\bs_\bi_\bo_\bn_\bs - primitive
     and user-defined _\bf_\bp functions combined by _\bf_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\ba_\bl _\bf_\bo_\br_\bm_\bs.
     These forms take functional arguments and return functional
     results.  For example, the composition operator '@' takes
     two functional arguments and returns a function which
     represents their composition.

     There exists a single operation in _\bf_\bp - _\ba_\bp_\bp_\bl_\bi_\bc_\ba_\bt_\bi_\bo_\bn. This
     operation causes the system to evaluate the indicated func-
     tion using the single argument as input (all functions are
     monadic).

G\bGE\bET\bTT\bTI\bIN\bNG\bG S\bST\bTA\bAR\bRT\bTE\bED\bD
     _\bF_\bp invokes the system. _\bF_\bp compiles functions into _\bl_\bi_\bs_\bp(1)
     source code; _\bl_\bi_\bs_\bp(1) interprets this code (the user may com-
     pile this code using the liszt (1) compiler to gain a factor
     of 10 in performance).  _\bC_\bo_\bn_\bt_\br_\bo_\bl _\bD exits back to the shell.
     _\bB_\br_\be_\ba_\bk terminates any computation in progress  and resets any
     open file units.  )_\bh_\be_\bl_\bp provides a short summary of all user
     commands.

F\bFI\bIL\bLE\bES\bS
     /usr/ucb/lisp  the FRANZ LISP interpreter
     /usr/ucb/liszt the liszt compiler
     /usr/doc/fp    the User's Guide

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
     lisp(1), liszt(1).

     _\bT_\bh_\be _\bB_\be_\br_\bk_\be_\bl_\be_\by _\bF_\bP _\bu_\bs_\be_\br'_\bs _\bm_\ba_\bn_\bu_\ba_\bl, available on-line.  The
     language is described  in  the August 1978 issue of _\bC_\bA_\bC_\bM
     (Turing award lecture by John Backus).

B\bBU\bUG\bGS\bS


Printed 7/9/88           April 29, 1985                         1


FP(1)               UNIX Programmer's Manual                FP(1)


     If a non-terminating function is applied as the result of
     loading a file, then control is returned to the user immedi-
     ately, everything after that position in the file is
     ignored.

     FP incorrectly marks the location of a syntax error on
     large, multi-line function definitions or applications.

A\bAU\bUT\bTH\bHO\bOR\bR
     Scott B. Baden


Printed 7/9/88           April 29, 1985                         2