--- loncom/homework/default_homework.lcpm 2004/05/27 04:25:13 1.84 +++ loncom/homework/default_homework.lcpm 2006/12/15 22:11:43 1.123 @@ -1,7 +1,7 @@ # The LearningOnline Network with CAPA # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run() # -# $Id: default_homework.lcpm,v 1.84 2004/05/27 04:25:13 albertel Exp $ +# $Id: default_homework.lcpm,v 1.123 2006/12/15 22:11:43 www Exp $ # # Copyright Michigan State University Board of Trustees # @@ -33,6 +33,99 @@ $pi=atan2(1,1)*4; $rad2deg=180.0/$pi; $deg2rad=$pi/180.0; $"=' '; +use strict; +{ + my $n = 0; + my $total = 0; + my $num_left = 0; + my @order; + my $type; + + sub init_permutation { + my ($size,$requested_type) = @_; + @order = (0..$size-1); + $n = $size; + $type = $requested_type; + if ($type eq 'ordered') { + $total = $num_left = 1; + } elsif ($type eq 'unordered') { + $total = $num_left = &factorial($size); + } else { + die("Unkown type: $type"); + } + } + + sub get_next_permutation { + if ($num_left == $total) { + $num_left--; + return \@order; + } + + # Find largest index j with a[j] < a[j+1] + + my $j = scalar(@order) - 2; + while ($order[$j] > $order[$j+1]) { + $j--; + } + + # Find index k such that a[k] is smallest integer + # greater than a[j] to the right of a[j] + + my $k = scalar(@order) - 1; + while ($order[$j] > $order[$k]) { + $k--; + } + + # Interchange a[j] and a[k] + + @order[($k,$j)] = @order[($j,$k)]; + + # Put tail end of permutation after jth position in increasing order + + my $r = scalar(@order) - 1; + my $s = $j + 1; + + while ($r > $s) { + @order[($s,$r)]=@order[($r,$s)]; + $r--; + $s++; + } + + $num_left--; + return(\@order); + } + + sub get_permutations_left { + return $num_left; + } +} + +sub check_commas { + my ($response)=@_; + #print("$response "); + my @numbers=split(',',$response); + #print(" numbers ".join('-',@numbers)." "); + if (scalar(@numbers) > 1) { + #print(" numbers[0] ".$numbers[0]." "); + if (length($numbers[0]) > 3 || length($numbers[0]) == 0) { return -1; } + shift(@numbers); + #print(" numbers ".scalar(@numbers)." "); + while (scalar(@numbers) > 1) { + #print(" numbers ".join('-',@numbers)." "); + if (length($numbers[0]) != 3) { return -2; } + shift(@numbers); + } + my ($number)=split('\.',$numbers[0]); + #print(" number ".$number." "); + #print(" numbers[0] ".$numbers[0]." "); + if (length($number) != 3) { return -3; } + } else { + my ($number)=split('\.',$numbers[0]); + if (length($number) > 3) { return -4; } + } + return 1; +} + sub caparesponse_check { my ($answer,$response)=@_; @@ -41,7 +134,7 @@ sub caparesponse_check { my $type=$LONCAPA::CAPAresponse_args{'type'}; my $tol=$LONCAPA::CAPAresponse_args{'tol'}; my $sig=$LONCAPA::CAPAresponse_args{'sig'}; - my $ans_fmt=$LONCAPA::CAPAresponse_args{'ans_fmt'}; + my $ans_fmt=$LONCAPA::CAPAresponse_args{'format'}; my $unit=$LONCAPA::CAPAresponse_args{'unit'}; my $calc=$LONCAPA::CAPAresponse_args{'calc'}; my $samples=$LONCAPA::CAPAresponse_args{'samples'}; @@ -52,39 +145,53 @@ sub caparesponse_check { #type's definitons come from capaParser.h - my $message=''; + #remove leading and trailing whitespace if (!defined($response)) { $response=''; } if ($response=~ /^\s|\s$/) { $response=~ s:^\s+|\s+$::g; - $message .="Removed ws now :$response:\n"; - } else { - $message .="no ws in :$response:\n"; + &LONCAPA_INTERNAL_DEBUG("Removed ws now :$response:"); } - if ($type eq 'cs' || $type eq 'ci' || $type eq 'mc') { + + #&LONCAPA_INTERNAL_DEBUG(" type is $type "); + if ($type eq 'cs' || $type eq 'ci') { #for string answers make surec all places spaces occur, there is #really only 1 space, in both the answer and the response $answer=~s/ +/ /g; $response=~s/ +/ /g; + } elsif ($type eq 'mc') { + $answer=~s/[\s,]//g; + $response=~s/[\s,]//g; + } + if ($type eq 'float' && $unit=~/\$/) { + if ($response!~/^\$/) { return ('NO_UNIT', undef); } + $response=~s/\$//g; } + if ($type eq 'float' && $unit=~/\,/ && (&check_commas($response)<0)) { + return "COMMA_FAIL:"; + } + $ans_fmt=~s/\W//g; + $unit=~s/[\$,]//g; if ($type eq 'float') { $response=~s/,//g; } - if (length($response) > 500) { return "TOO_LONG: Answer too long"; } + + if (length($response) > 500) { return ('TOO_LONG',undef); } if ($type eq '' ) { - $message .= "Didn't find a type :$type: defaulting\n"; + &LONCAPA_INTERNAL_DEBUG("Didn't find a type :$type: defaulting"); if ( $answer eq ($answer *1.0)) { $type = 2; } else { $type = 3; } } else { - if ($type eq 'cs') { $type = 4; } + if ($type eq 'cs') { $type = 4; } elsif ($type eq 'ci') { $type = 3 } elsif ($type eq 'mc') { $type = 5; } elsif ($type eq 'fml') { $type = 8; } + elsif ($type eq 'math') { $type = 9; } elsif ($type eq 'subj') { $type = 7; } elsif ($type eq 'float') { $type = 2; } elsif ($type eq 'int') { $type = 1; } - else { return "ERROR: Unknown type of answer: $type" } + else { return ('ERROR', "Unknown type of answer: $type") } } my $points; @@ -92,7 +199,7 @@ sub caparesponse_check { #formula type setup the sample points if ($type eq '8') { ($id_list,$points)=split(/@/,$samples); - $message.="Found :$id_list:$points: points in $samples\n"; + &LONCAPA_INTERNAL_DEBUG("Found :$id_list:$points: points in $samples"); } if ($tol eq '') { $tol=0.0; @@ -106,25 +213,24 @@ sub caparesponse_check { } } - if ($sig eq '') { - $sig_lbound = 0; #SIG_LB_DEFAULT - $sig_ubound =15; #SIG_UB_DEFAULT - } else { - ($sig_lbound,$sig_ubound) = split /,/,$sig; - if (!defined($sig_lbound)) { - $sig_lbound = 0; #SIG_LB_DEFAULT - $sig_ubound =15; #SIG_UB_DEFAULT - } - if (!defined($sig_ubound)) { $sig_ubound=$sig_lbound; } - } + ($sig_ubound,$sig_lbound)=&LONCAPA_INTERNAL_get_sigrange($sig); + my $reterror=""; - my $result = &caparesponse_capa_check_answer($response,$answer,$type, + my $result; + if ($type eq '9') { + $result = &maxima_check(&maxima_cas_formula_fix($response),&maxima_cas_formula_fix($answer),\$reterror); + } else { + if ($type eq '8') { # fml type + $response = &capa_formula_fix($response); + $answer = &capa_formula_fix($answer); + } + $result = &caparesponse_capa_check_answer($response,$answer,$type, $tol_type,$tol, $sig_lbound,$sig_ubound, $ans_fmt,$unit,$calc,$id_list, $points,$external::randomseed, \$reterror); - + } if ($result == '1') { $result='EXACT_ANS'; } elsif ($result == '2') { $result='APPROX_ANS'; } elsif ($result == '3') { $result='SIG_FAIL'; } @@ -136,6 +242,8 @@ sub caparesponse_check { elsif ($result == '9') { $result='ANS_CNT_NOT_MATCH'; } elsif ($result =='10') { $result='SUB_RECORDED'; } elsif ($result =='11') { $result='BAD_FORMULA'; } + elsif ($result =='12' && !$response) { $result='MISSING_ANSWER'; } + elsif ($result =='12') { $result='WANTED_NUMERIC'; } elsif ($result =='13') { $result='UNIT_INVALID_INSTRUCTOR'; } elsif ($result =='141') { $result='UNIT_INVALID_STUDENT'; } elsif ($result =='142') { $result='UNIT_INVALID_STUDENT'; } @@ -143,60 +251,170 @@ sub caparesponse_check { elsif ($result =='15') { $result='UNIT_IRRECONCIBLE'; } else {$result = "ERROR: Unknown Result:$result:$@:";} - return ("$result:\nRetError $reterror:\nAnswer $answer:\nResponse $response:\n type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|\n$message",$reterror); + &LONCAPA_INTERNAL_DEBUG("RetError $reterror: Answer $answer: Response $response: type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|"); + &LONCAPA_INTERNAL_DEBUG(" $answer $response $result "); + return ($result,$reterror) } sub caparesponse_check_list { - my $response=$LONCAPA::CAPAresponse_args{'response'}; - my ($result,@list); - @list=@LONCAPA::CAPAresponse_answer; - my $aresult=''; - my $current_answer; - my $answers=join(':',@list); - $result.="Got response :$answers:\n"; - &LONCAPA_INTERNAL_DEBUG("Yo! got ".join(':',%LONCAPA::CAPAresponse_args)); - my @responselist; + my $responses=$LONCAPA::CAPAresponse_args{'response'}; +# &LONCAPA_INTERNAL_DEBUG(" answer is ". +# &LONCAPA_INTERNAL_Dumper($LONCAPA::CAPAresponse_answer).":\n"); +# &LONCAPA_INTERNAL_DEBUG(" respons is ". +# &LONCAPA_INTERNAL_Dumper($responses).":\n"); + &LONCAPA_INTERNAL_DEBUG("args ".join(':',%LONCAPA::CAPAresponse_args)); my $type = $LONCAPA::CAPAresponse_args{'type'}; - $result.="Got type :$type:\n"; - if ($type ne '' && $#list > 0) { - (@responselist)=split /,/,$response; - } else { - (@responselist)=($response); + &LONCAPA_INTERNAL_DEBUG("Got type :$type:\n"); + + my $num_input_lines = + scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}}); + + if ($type ne '' ) { + if (scalar(@$responses) < $num_input_lines) { + return 'MISSING_ANSWER'; + } + if (scalar(@$responses) > $num_input_lines) { + return 'EXTRA_ANSWER'; + } + } - my $unit=''; - $result.="Initial final response :$responselist['-1']:\n"; + + foreach my $which (0..($num_input_lines-1)) { + my $answer_size = + scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]}); + if ($type ne '' + && $answer_size > 1) { + $responses->[$which]=[split(/,/,$responses->[$which])]; + } else { + $responses->[$which]=[$responses->[$which]]; + } + } +# &LONCAPA_INTERNAL_DEBUG(" parsed response is ". +# &LONCAPA_INTERNAL_Dumper($responses).":\n"); + foreach my $which (0..($num_input_lines-1)) { + my $answer_size = + scalar(@{$LONCAPA::CAPAresponse_answer->{'answers'}[$which]}); + my $response_size = + scalar(@{$responses->[$which]}); + if ($answer_size > $response_size) { + return 'MISSING_ANSWER'; + } + if ($answer_size < $response_size) { + return 'EXTRA_ANSWER'; + } + } + + &LONCAPA_INTERNAL_DEBUG("Initial final response :$responses->[0][-1]:"); + my $unit; if ($type eq '' || $type eq 'float') { #for numerical problems split off the unit - if ( $responselist['-1']=~ /(.*[^\s])\s+([^\s]+)/ ) { - $responselist['-1']=$1; + if ( $responses->[0][-1]=~ /(.*[^\s])\s+([^\s]+)/ ) { + $responses->[0][-1]=$1; $unit=$2; } } - $result.="Final final response :$responselist['-1']:$unit:\n"; - $result.=":$#list: answers\n"; + &LONCAPA_INTERNAL_DEBUG("Final final response :$responses->[0][-1]:$unit:"); $unit=~s/\s//; - my $i=0; - my $awards=''; - my @msgs; - for ($i=0; $i<@list;$i++) { - my $msg; - $result.="trying answer :$list[$i]:\n"; - my $thisanswer=$list[$i]; - $result.="trying answer :$thisanswer:\n"; - if ($unit eq '') { - ($aresult,$msg)=&caparesponse_check($thisanswer,$responselist[$i]); - } else { - ($aresult,$msg)=&caparesponse_check($thisanswer, - $responselist[$i]." $unit"); + if ($unit ne '') { + foreach my $response (@$responses) { + foreach my $element (@$response) { + $element .= " $unit"; + } + } + } + + foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) { + if (!defined($thisanswer)) { + return ('ERROR','answer was undefined'); + } + } + + +# &LONCAPA_INTERNAL_DEBUG(&LONCAPA_INTERNAL_Dumper($responses)); + my %memoized; + if ($LONCAPA::CAPAresponse_answer->{'type'} eq 'ordered') { + for (my $i=0; $i{'answers'}[$i]; + my $response = $responses->[$i]; + my $key = "$answer\0$response"; + my (@awards,@msgs); + for (my $j=0; $j[$j], + $response->[$j]); + push(@awards,$award); + push(@msgs, $msg); + } + my ($award,$msg) = + &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs); + $memoized{$key} = [$award,$msg]; + } + } else { + #FIXME broken with unorder responses where one is a + # and the other is a (need to delay parse til + # inside the loop?) + foreach my $response (@$responses) { + my $response_size = scalar(@{$response}); + foreach my $answer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) { + my $key = "$answer\0$response"; + my $answer_size = scalar(@{$answer}); + my ($award,$msg); + if ($answer_size > $response_size) { + $award = 'MISSING_ANSWER'; + } elsif ($answer_size < $response_size) { + $award = 'EXTRA_ANSWER'; + } else { + my (@awards,@msgs); + for (my $j=0; $j[$j], + $response->[$j]); + push(@awards,$award); + push(@msgs, $msg); + } + ($award,$msg) = + &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs); + } + $memoized{$key} = [$award,$msg]; + } } - my ($temp)=split /:/, $aresult; - $awards.="$temp,"; - $result.=$aresult; - push(@msgs,$msg); } - chop $awards; - return ("$awards:\n$result",@msgs); + + my ($final_award,$final_msg); + &init_permutation(scalar(@$responses), + $LONCAPA::CAPAresponse_answer->{'type'}); + + # possible FIXMEs + # - significant time is spent calling non-safe space routine + # from safe space + # - early outs could be possible with classifying awards is to stratas + # and stopping as so as hitting the top strata + # - some early outs also might be possible with check ing the + # memoized hash of results (is correct even possible? etc.) + + my (@final_awards,@final_msg); + while( &get_permutations_left() ) { + my $order = &get_next_permutation(); + my (@awards, @msgs, $i); + foreach my $thisanswer (@{ $LONCAPA::CAPAresponse_answer->{'answers'} }) { + my $key = "$thisanswer\0".$responses->[$order->[$i]]; + push(@awards,$memoized{$key}[0]); + push(@msgs,$memoized{$key}[1]); + $i++; + + } + &LONCAPA_INTERNAL_DEBUG(" all awards ".join(':',@awards)); + + my ($possible_award,$possible_msg) = + &LONCAPA_INTERNAL_FINALIZEAWARDS(\@awards,\@msgs); + &LONCAPA_INTERNAL_DEBUG(" pos awards ".$possible_award); + push(@final_awards,$possible_award); + push(@final_msg,$possible_msg); + } + + &LONCAPA_INTERNAL_DEBUG(" all final_awards ".join(':',@final_awards)); + my ($final_award,$final_msg) = + &LONCAPA_INTERNAL_FINALIZEAWARDS(\@final_awards,\@final_msg,undef,1); + return ($final_award,$final_msg); } sub tex { @@ -353,7 +571,7 @@ sub random_multivariate_normal { my ($item_cnt,$seed,$mean,$covar) = @_; my @oldseed=&random_get_seed(); &random_set_seed_from_phrase($seed); - @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar); + my @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar); &random_set_seed(@oldseed); return @retArray; } @@ -363,7 +581,7 @@ sub random_multinomial { my @oldseed=&random_get_seed(); my @retArray; &random_set_seed_from_phrase($seed); - @retArray=&math_random_multinomial($item_cnt,@p); + my @retArray=&math_random_multinomial($item_cnt,@p); &random_set_seed(@oldseed); return @retArray; } @@ -418,14 +636,14 @@ sub random_negative_binomial { return @retArray; } -sub abs { abs(shift) } -sub sin { sin(shift) } -sub cos { cos(shift) } -sub exp { exp(shift) } -sub int { int(shift) } -sub log { log(shift) } -sub atan2 { atan2($_[0],$_[1]) } -sub sqrt { sqrt(shift) } +sub abs { CORE::abs(shift) } +sub sin { CORE::sin(shift) } +sub cos { CORE::cos(shift) } +sub exp { CORE::exp(shift) } +sub int { CORE::int(shift) } +sub log { CORE::log(shift) } +sub atan2 { CORE::atan2($_[0],$_[1]) } +sub sqrt { CORE::sqrt(shift) } sub tan { CORE::sin($_[0]) / CORE::cos($_[0]) } #sub atan { atan2($_[0], 1); } @@ -489,10 +707,15 @@ sub format { #if ($options =~ /\$/) { $dollamode=1; } #if ($options =~ /,/) { $commamode=1; } if ($options =~ /\./) { $alwaysperiod=1; } - $fmt=~s/e/E/g; - my $result=sprintf('%.'.$fmt,$value); - if ($alwaysperiod && $fmt eq '0f') { $result .='.'; } - $result=~s/(E[+-]*)0/$1/; + my $result; + if ($fmt=~/s$/i) { + $result=&format_significant_figures($value,$fmt); + } else { + $fmt=~s/e/E/g; + $result=sprintf('%.'.$fmt,$value); + if ($alwaysperiod && $fmt eq '0f') { $result .='.'; } + $result=~s/(E[+-]*)0/$1/; + } #if ($dollarmode) {$result=&dollarformat($result);} #if ($commamode) {$result=&commaformat($result);} return $result; @@ -500,25 +723,34 @@ sub format { sub chemparse { my ($reaction) = @_; - my @tokens = split(/(\s\+|\->|<=>)/,$reaction); + my @tokens = split(/(\s\+|\->|<=>|<\-|\.)/,$reaction); my $formula = ''; foreach my $token (@tokens) { if ($token eq '->' ) { $formula .= '\ensuremath{\rightarrow} '; next; } + if ($token eq '<-' ) { + $formula .= '\ensuremath{\leftarrow} '; + next; + } if ($token eq '<=>') { if ($external::target eq 'web' && &EXT('request.browser.unicode')) { $formula .= '⇌ '; } else { $formula .= &web('<=> ','\ensuremath{\rightleftharpoons} ', - '<=$gt; '); + '<=> '); } next; } - $token =~ /^\s*(\d*)(.*)/; - $formula .= $1 if ($1 > 1); # stoichiometric coefficient + if ($token eq '.') { + $formula =~ s/(\ \;| )$//; + $formula .= '·'; + next; + } + $token =~ /^\s*([\d|\/]*(?:&frac\d\d)?)(.*)/; + $formula .= $1 if ($1 ne '1'); # stoichiometric coefficient my $molecule = $2; # subscripts @@ -529,11 +761,11 @@ sub chemparse { $molecule =~ s/\s*//g; # forced space $molecule =~ s/_/ /g; + $molecule =~ s/-/−/g; $formula .= $molecule.' '; } # get rid of trailing space - $formula =~ s/(\Q${nbsp}\E| )$//; - + $formula =~ s/(\ \;| )$//; return &xmlparse($formula); } @@ -544,10 +776,14 @@ sub prettyprint { if ($fmt =~ /chem/i) { return(&chemparse($value)); } my ($dollarmode,$commamode,$alwaysperiod,$options); if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; } - if ($options =~ /\$/) { $dollamode=1; } + if ($options =~ /\$/) { $dollarmode=1; } if ($options =~ /,/) { $commamode=1; } if ($options =~ /\./) { $alwaysperiod=1; } - if ($fmt) { $value=sprintf('%.'.$fmt,$value); } + if ($fmt=~/s$/i) { + $value=&format_significant_figures($value,$fmt); + } elsif ($fmt) { + $value=sprintf('%.'.$fmt,$value); + } if ($alwaysperiod && $fmt eq '0f') { if ($target eq 'tex') { $value .='\\ensuremath{.}'; @@ -577,8 +813,8 @@ sub prettyprint { } } else { $result=$value; - if ($dollarmode) { $result=&dollarformat($result,$target); } - if ($commamode) { $result=&commaformat($result,$target); } + if ($dollarmode) { $result=&dollarformat($result,$target); } + elsif ($commamode) { $result=&commaformat($result,$target); } } return $result; } @@ -586,12 +822,12 @@ sub prettyprint { sub commaformat { my ($number,$target) = @_; if ($number =~ /\./) { - while ($number =~ /([^\.,]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) { - $number = $1.','.$2.$3; + while ($number =~ /([^0-9]*)([0-9]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) { + $number = $1.$2.','.$3.$4; } } else { - while ($number =~ /([^,]+)([^,][^,][^,])([,0-9]*)$/) { - $number = $1.','.$2.$3; + while ($number =~ /^([^0-9]*)([0-9]+)([^,][^,][^,])([,0-9]*)$/) { + $number = $1.$2.','.$3.$4; } } return $number; @@ -609,6 +845,41 @@ sub dollarformat { return $number; } +# format of form ns or nS where n is an integer +sub format_significant_figures { + my ($number,$format) = @_; + return '0' if ($number == 0); + # extract number of significant figures needed + my ($sig) = ($format =~ /(\d+)s/i); + # arbitrary choice - suggestions ?? or throw error message? + $sig = 3 if ($sig eq ''); + # save the minus sign + my $sign = ($number < 0) ? '-' : ''; + $number = abs($number); + # needed to correct for a number greater than 1 (or + my $power = ($number < 1) ? 0 : 1; + # could round up. Take the integer part of log10. + my $x10 = int(log($number)/log(10)); + # find number with values left of decimal pt = # of sign figs. + my $xsig = $number*10**($sig-$x10-$power); + # get just digits left of decimal pt - also rounds off correctly + my $xint = sprintf('%.0f',$xsig); + # save any trailing zero's + my ($zeros) = ($xint =~ /(0+)$/); + # return number to original magnitude + my $numSig = $xint*10**($x10-$sig+$power); + # insert trailing zero's if have decimal point + $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/; + # put a decimal pt for number ending with 0 and length = # of sig fig + $numSig.='.' if (length($numSig) == $sig && $numSig =~ /0$/); + if (length($numSig) < $sig) { + $numSig.='.'.substr($zeros,0,($sig-length($numSig))); + } + # return number with sign + return $sign.$numSig; + +} + sub map { my ($phrase,$dest,$source)=@_; my @oldseed=&random_get_seed(); @@ -720,6 +991,18 @@ sub class { return $course; } +sub firstname { + my $firstname = &EXT('environment.firstname'); + $firstname = '' if $firstname eq ""; + return $firstname; +} + +sub lastname { + my $lastname = &EXT('environment.lastname'); + $lastname = '' if $lastname eq ""; + return $lastname; +} + sub sec { my $sec = &EXT('request.course.sec'); $sec = '' if $sec eq ""; @@ -804,6 +1087,30 @@ sub choose { return $_[$num]; } +#&sum1(1,$x,sub { &sum1($_[0],2*$_[0], sub { fact($_[0])**2 })}); +#sub sum1 { +# my ($start,$end,$sub)=@_; +# my $sum=0; +# for (my $i=$start;$i<=$end;$i++) { +# $sum+=&$sub($i); +# } +# return $sum +#} + +#&sum2('a',1,$x,'&sum2(\'b\',$a,2*$a, \'&factorial($b)**2\')'); +#sub sum2 { +# my ($varname,$start,$end,$line)=@_; +# my $sum=0; +# for (my $i=$start;$i<=$end;$i++) { +# my $func=sub { +# eval("\$".$varname."=$i"); +# eval($line); +# }; +# $sum+=&$func($i); +# } +# return $sum +#} + # expiremental idea sub proper_path { my ($path)=@_;