Remote agent/Agent logic

From Rosetta Code
Remote agent/Agent logic is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

In Remote agent, a game is described where an agent interacts with a simple world of walls, balls and squares, and a component is described that marshals commands between the simulation environment and the logic code behind the agent.

The goal conditions for the game are to get all balls in squares of matching colors, in as few turns as possible.

Using an interface for your language write a program that attempts to reach these goals. The exact agent behavior within the simulated environment is unspecified.

C

See Remote agent/Simulation/C

Go

<lang go>package agent

import ( 

   "log"
   "math/rand"
   "time"

   "ra/ifc"

)

// The agent's awareness is quite limited. It has no representation of the // maze, which direction it is facing, or what it did last. It notices and // remembers just three things: The color of the sector just entered, the // presense and color of any ball there, and the presense and color of any // ball it is holding. var sectorColor, sectorBall, agentBall byte

// Package level variable to simplify function calls. var stream ifc.Streamer

func Agent(s ifc.Streamer) { 

   stream = s
   // randomness used for movement
   rand.Seed(time.Now().Unix())
   // handshake
   hs := stream.Rec()
   if hs != ifc.Handshake {
       log.Fatal("agent: thats no handshake")
   }
   stream.Send(ifc.Handshake)
   // agent behavior main loop
   for gameOver := false; !gameOver; {
       findMisplaced()
       get()
       findMatching()
       gameOver = drop()
   }

}

// noColor is not part of the interface or the world's representation. // It is used by the agent as a test for receipt of a color-based event. const noColor byte = '-'

// Move moves one sector in a random direction. // It retries on bumps and doesn't return until a forward command succeeds. // It expects a color event on a successful move and terminates if it doesn't // get one. func move() { 

   for {
       // Randomness:  50/50 chance of turning or attempting move.
       // For turns, equal chance of turning right or left.
       switch rand.Intn(4) {
       case 0:
           stream.Send(ifc.CmdLeft)
           for stream.Rec() != ifc.EvStop {
           }
           continue
       case 1:
           stream.Send(ifc.CmdRight)
           for stream.Rec() != ifc.EvStop {
           }
           continue
       }
       stream.Send(ifc.CmdForward)
       bump := false
       sectorColor = noColor
       sectorBall = noColor
   events:
       for {
           switch ev := stream.Rec(); ev {
           case ifc.EvBump:
               bump = true
           case ifc.EvColorRed, ifc.EvColorGreen,
               ifc.EvColorYellow, ifc.EvColorBlue:
               sectorColor = ev
           case ifc.EvBallRed, ifc.EvBallGreen,
               ifc.EvBallYellow, ifc.EvBallBlue:
               sectorBall = ev
           case ifc.EvStop:
               break events
           }
       }
       if bump {
           continue
       }
       if sectorColor == noColor {
           log.Fatal("agent: expected color event after move")
       }
       return
   }

}

// FindMisplaced wanders the maze looking for a ball on the wrong sector. func findMisplaced() { 

   for {
       move()
       // get ball from current sector if meaningful
       switch sectorBall {
       case ifc.EvBallRed, ifc.EvBallGreen,
           ifc.EvBallYellow, ifc.EvBallBlue:
           if sectorBall != sectorColor+32 {
               return
           }
       }
   }

}

// Get is only called when get is possible. func get() { 

   stream.Send(ifc.CmdGet)
   for {
       switch stream.Rec() {
       case ifc.EvStop:
           // agent notes ball color, and that sector is now empty
           agentBall = sectorBall
           sectorBall = noColor
           return
       case ifc.EvNoBallInSector, ifc.EvAgentFull:
           log.Fatal("agent: expected get to succeed")
       }
   }

}

// There's a little heuristic built in to findMatching and drop. // Ideally, findMatching finds an empty sector matching the ball that the // agent is holding and then drop drops it there. FindMatching returns // with partial success however, if it finds a sector matching the ball // where the sector is not empty, but contains a ball of the wrong color. // In this case, drop will drop the ball on the nearest empty sector, // in hopes that it has at least moved the ball near a sector where it // might ultimately go.

// FindMatching is only called when agent has a ball. // FindMatching finds a sector where the color matches the ball the agent // is holding and which does not already contain a matching ball. // It does not necessarily find an empty matching sector. func findMatching() { 

   for sectorColor+32 != agentBall || agentBall == sectorBall {
       move()
   }

}

// Drop is only called when the agent has a ball. Unlike get() however, // drop() can be called whether the sector is empty or not. drop() means // drop as soon as possible, so if the sector is full, drop() will wander // at random looking for an empty sector. func drop() (gameOver bool) { 

   for sectorBall != noColor {
       move()
   }
   // expected to work
   stream.Send(ifc.CmdDrop)

ev: 

   for {
       switch stream.Rec() {
       case ifc.EvGameOver:
           gameOver = true
       case ifc.EvStop:
           break ev
       case ifc.EvNoBallInAgent, ifc.EvSectorFull:
           log.Fatal("expected drop to succeed")
       }
   }
   sectorBall = agentBall
   agentBall = noColor
   return

}</lang>


Julia

See Remote agent/Agent_logic/Julia


Perl

This is the agent. It talks over tcp. Start it with an argument of "host:port". With no argument it will default to "localhost:3141". It should be run in a terminal that understand ANSI escape sequences, because it shows the world it has found as it looks for all sectors first and then goes around cleaning up the mismatches second. Empty sectors are shown in blue, sectors with a matching ball are shown in green, and sectors with a mismatching ball are shown in red. <lang perl>#!/usr/bin/perl

use strict; # https://rosettacode.org/wiki/Remote_agent use warnings; use IO::Socket; use List::Util qw( shuffle first ); use Time::HiRes qw( sleep time ); $SIG{__WARN__} = sub { die @_ }; $/ = '.'; $| = 1; my $delay = 0; my $show = 1;

my $server = shift // 'localhost:3141'; my $socket = IO::Socket::INET->new($server) or die $@; getc $socket eq 'A' ? print $socket 'A' : die "no handshake"; my $start = time;

my ($wide, $high) = (3, 3); my $grid = (' ' x $wide . " \n") x $high; my $gap = $wide * 2 + 2; my %gap = ( N => -$gap, E => 2, S => $gap, W => -2 ); my $dir = 'N'; my $agent = $gap * ($high >> 1) + 2 * ($wide >> 1); my @wrong = map { my $f = $_; 

 map { $f eq $_ ? () : "$f\l$_" } qw(R G B Y) } qw(R G B Y);

my $wrong = qr/(?:@{[ join '|', @wrong ]})/; my $success = ; my $turns = 0; $show and print "\e[H\e[J";

sub show 

 {
 $show and print "\e[H$grid\n" =~ s/([RGBY])([rgby])/ $1 eq uc $2 ?
   "\e[92m$1$2\e[m" : "\e[91m$1$2\e[m" /ger =~ s/[RGBY] /\e[94m$&\e[m/gr;
 }

sub out { substr $grid, $agent, 2, shift }

sub at { substr $grid, shift, 2 }

sub command 

 {
 $turns += print $socket @_;
 local $_ = <$socket>;
 /\|/ or $turns++;
 $_;
 }

sub set # sends command to rotate from current dir to requested dir 

 {
 my $want = shift;
 $want =~ /^[NESW]$/ or die "bad dir $want";
 $want eq $dir and return;
 command $_ for split //,
   'NESWN' =~ /$dir$want/ ? '>' : 'NWSEN' =~ /$dir$want/ ? '<' : '>>';
 $dir = $want;
 }

sub expand # the grid if color sector on edge 

 {
 if( $grid =~ /\w.*$/ )
   {
   $grid .= '  ' x $wide . " \n";
   $high += 1;
   }
 elsif( $grid =~ /^.*\w/ )
   {
   $grid = '  ' x $wide . " \n" . $grid;
   $agent += 2 * ($wide + 1);
   $high += 1;
   }
 elsif( $grid =~ /^\w/m )
   {
   my $lines = $` =~ tr/\n//;
   $grid =~ s/^/  /gm;
   $agent += 2 * (1 + $lines);
   $wide++;
   }
 elsif( $grid =~ /\w. \n/ )
   {
   my $lines = $` =~ tr/\n//;
   $grid =~ s/\n/  \n/g;
   $agent += 2 * $lines;
   $wide++;
   }
 $gap = 2 * ($wide + 1); # if changed vertical step
 %gap = ( N => -$gap, E => 2, S => $gap, W => -2 );
 }

sub moveto 

 {
 my ($to) = @_;
 $agent == $to and return;
 my $bloc = $agent >> 1;
 local $_ = $grid =~ s/(.).| (\n)/$+/gr;
 tr/RGBY |/    -/;
 substr $_, $to >> 1, 1, 'd';
 my $gap = /\n/ && $-[0];
 substr $_, $bloc, 1, ' ';
 while( ' ' eq substr $_, $bloc, 1 )
   {
   my $west = ((tr/-/ /r =~ s/(.*)./ $1/gr | $_) &
     tr/dnesw /     \xff/r) =~ tr/a-\x7f/w/r;
   my $east = ((tr/-/ /r =~ s/.(.*)/$1 /gr | $_) &
     tr/dnesw /     \xff/r) =~ tr/a-\x7f/ e/r;
   my $south = ((substr($_, $gap + 1) =~ tr/-/ /r | $_) &
     tr/dnesw /     \xff/r) =~ tr/a-\x7f/ s/r;
   my $north = (((' ' x $gap . "\n" . substr($_, 0, -$gap - 1)) =~
     tr/-/ /r | $_) & tr/dnesw /     \xff/r) =~ tr/a-\x7f/ n/r;
   $_ = ($_ & $south =~ tr/ w/\xff\0/r) | $south;
   $_ = ($_ & $north =~ tr/ w/\xff\0/r) | $north;
   $_ = ($_ & $west =~ tr/ w/\xff\0/r) | $west;
   $_ = ($_ & $east =~ tr/ w/\xff\0/r) | $east;
   "$east$west$north$south" =~ /\w/ or die "d not found";
   }
 my $path = ;
 my %gap = (N => -$gap - 1, S => $gap + 1, E => 1, W => -1);
 while( 1 )
   {
   my $dir = uc substr $_, $bloc, 1;
   $dir =~ /[NESW]/ or last;
   $path .= $dir;
   $bloc += $gap{$dir};
   }
 set($_), $_ = command( '^' ), /[|]/ && die "wall during moveto"
   for split //, $path; # walk agent along path
 $agent = $to; # arrived
 }

while( $grid =~ / / ) ############################################ main 

 {
 show;
 $delay and sleep $delay;
 $agent % 2 and die "$agent is odd";
 my $v = qr/(?:..){$wide}/s;
 if( $grid =~ /[RGBY]/ )
   {
   my ($in, $face) =
     at( $agent - 2 ) eq '  ' ? ($agent, 'W') :
     at( $agent + $gap{'N'} ) eq '  ' ? ($agent, 'N') :
     at( $agent + $gap{'S'} ) eq '  ' ? ($agent, 'S') :
     at( $agent + 2 ) eq '  ' ? ($agent, 'E') :
     $grid =~ /  ([RGBY].)/ ? ($-[1], 'W') :
     $grid =~ /([RGBY].)  / ? ($-[1], 'E') :
     $grid =~ /  $v([RGBY].)/ ? ($-[1], 'N') :
     $grid =~ /([RGBY].)$v  / ? ($-[1], 'S') : last;
   moveto($in);
   set($face);
   $_ = command '^';
   if( /\|/ ) { substr $grid, $agent + $gap{$dir}, 2, '||'; }
   else
     {
     $agent += $gap{$dir};
     out tr/RGBY//cdr . (tr/rgby//cdr || ' ');
     expand();
     }
   }
 else
   {
   substr($grid, $agent + $gap{$dir}, 2, '||'),
     set('NESWN' =~ /$dir(.)/ ? $1 : die "bad dir")
     while $_ = command('^'), /\|/;
   $agent += $gap{$dir};
   out tr/RGBY//cdr . (tr/rgby//cdr || ' ');
   expand();
   }
 }

show; tr/R// >= tr/r// && tr/G// >= tr/g// && tr/B// >= tr/b// && tr/Y// >= tr/y// 

 && tr/RGBY// > tr/rgby// or die "invalid ball counts" for $grid;
  1. $grid =~ /$wrong/ ? print "swapping\n" : print "no swapping needed";

sub any 

 {
 my ($qr) = @_;
 my @any;
 push @any, $-[0] while $grid =~ /$qr/g;
 $any[rand @any];
 }

sub dist 

 {
 my ($x, $y) = map $_ >> 1, @_;
 my $w = $wide + 1;
 abs($x % $w - $y % $w) + abs(int($x / $w) - int($y / $w));
 }

sub nearest 

 {
 my ($qr, $from) = @_;
 my @dist;
 $dist[dist( $from, $-[0] )] = $-[0] while $grid =~ /$qr/g;
 first {defined} @dist;
 }

while( 1 ) 

 {
 show;
 my $from = nearest( qr/$wrong/, $agent ) or last;
 my $ball = substr $grid, $from + 1, 1;
 $grid =~ /\u$ball / or $from = any( qr/$wrong/ ),
   $ball = substr $grid, $from + 1, 1;
 my $to = nearest( qr/\u$ball /, $from ) || any( qr/[RGBY] / );
  1. my $to = ( $grid =~ /\u$ball / && $-[0] ) || any( qr/[RGBY] / );
 moveto($from);
 $_ = command '@';
 /[as]/i and die "ERROR $_ on get";
 substr $grid, $from + 1, 1, ' ';
 moveto($to);
 $_ = command '!';
 /[as]/i and die "ERROR $_ on drop";
 substr $grid, $to + 1, 1, $ball;
 /\+/ and $success = "\e[JSUCCESS          ", last;
 $delay and sleep $delay;
 }

show;

print $success, "\n"; printf "\n$turns turns took %.3f seconds %d usec/turn\n", time - $start, 

 (time - $start) / $turns * 1e6;

</lang>

PicoLisp

Implementation in PicoLisp.

Tcl

Sample agent (not a good or smart player of the game; just to show how to program to the interface).

Works with: Tcl version 8.6

<lang tcl>package require Tcl 8.6 package require RC::RemoteAgent

oo::class create Agent { 

   superclass AgentAPI
   variable sectorColor ballColor
   forward Behavior my MoveBehavior

   # How to move around
   method MoveBehavior {} {

set ball "" while 1 { try { while {rand() < 0.5} { my ForwardStep my BallBehavior } } trap bumpedWall {} {} if {rand() < 0.5} { my TurnLeft } else { my TurnRight } } set ::wonGame ok 

   }

   # How to handle the ball once we've arrived in a square
   method BallBehavior {} {

upvar 1 ball ball anywhere anywhere if { $ball eq "" && $ballColor ne "" && $ballColor ne $sectorColor } then { set ball [set ballTarget $ballColor] set anywhere 0 my GetBall } elseif { $ball ne "" && ($ball eq $sectorColor || $anywhere) } { try { if {[my DropBall]} { return -code break } set ball "" } trap sectorFull {} { # Target square full; drop this ball anywhere set anywhere 1 } } 

   }

}

Agent new "localhost" 12345 vwait wonGame</lang>

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