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Working version of algebra filter for Unix and Windows

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commit 1a1de46ae2a6da30cfe9f3ec6c58b188a67071e8 1 parent 3ce906d
fiedorow authored
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649 filter/algebra/AlgParser.pm
@@ -0,0 +1,649 @@
+
+
+## Last modification: 8/3/00 by akp
+## Originally written by Daniel Martin, Dept of Math, John Hopkins
+## Additions and modifications were made by James Martino, Dept of Math, John Hopkins
+## Additions and modifications were made by Arnold Pizer, Dept of Math, Univ of Rochester
+
+#use Data::Dumper;
+
+package AlgParser;
+use HTML::Entities;
+
+%close = ();
+
+sub new {
+ my $package = shift;
+ my (%ret);
+ $ret{string} = "";
+ $ret{posarray} = [];
+ $ret{parseerror} = "";
+ $ret{parseresult} = [];
+ bless \%ret, $package;
+ return \%ret;
+}
+
+sub inittokenizer {
+ my($self, $string) = @_;
+ $self->{string} =~ m/\G.*$/g;
+ $self->{string} = undef;
+ $self->{string} = $string;
+ $self->{string} =~ m/\G.*$/g;
+ $self->{string} =~ m/^/g;
+}
+
+$close{'{'} = '}';
+$close{'['} = ']';
+$close{'('} = ')';
+
+$binoper3 = '(?:\\^|\\*\\*)';
+$binoper2 = '[/*_,]';
+$binoper1 = '[-+=><%!#]';
+$openparen = '[{(\\[]';
+$closeparen = '[})\\]]';
+$varname = '[A-Za-z](?:_[0-9]+)?';
+$specialvalue = '(?:e|pi|da|db|dc|de|df|dg|dh|di|dj|dk|dl|dm|dn|do|dp|dq|dr|ds|dt|du|dv|dw|dx|dy|dz|infty)';
+$numberplain = '(?:\d+(?:\.\d*)?|\.\d+)';
+$numberE = '(?:' . $numberplain . 'E[-+]?\d+)';
+$number = '(?:' . $numberE . '|' . $numberplain . ')';
+#
+# DPVC -- 2003/03/31
+# added missing trig and inverse functions
+#
+#$trigfname = '(?:cosh|sinh|tanh|cot|(?:a(?:rc)?)?cos|(?:a(?:rc)?)?sin|' .
+# '(?:a(?:rc)?)?tan|sech?)';
+$trigfname = '(?:(?:a(?:rc)?)?(?:sin|cos|tan|sec|csc|cot)h?)';
+#
+# End DPVC
+#
+$otherfunc = '(?:exp|abs|logten|log|ln|sqrt|sgn|step|fact|int|lim|fun[a-zA-Z])';
+$funcname = '(?:' . $otherfunc . '|' . $trigfname . ')';
+
+$tokenregexp = "(?:($binoper3)|($binoper2)|($binoper1)|($openparen)|" .
+ "($closeparen)|($funcname)|($specialvalue)|($varname)|" .
+ "($numberE)|($number))";
+
+sub nexttoken {
+ my($self) = shift;
+ $self->{string} =~ m/\G\s+/gc;
+ my($p1) = pos($self->{string}) || 0;
+ if(scalar($self->{string} =~ m/\G$tokenregexp/gc)) {
+ push @{$self->{posarray}}, [$p1, pos($self->{string})];
+ if (defined($1)) {return ['binop3', $1];}
+ if (defined($2)) {return ['binop2', $2];}
+ if (defined($3)) {return ['binop1', $3];}
+ if (defined($4)) {return ['openp', $4];}
+ if (defined($5)) {return ['closep', $5];}
+ if (defined($6)) {return ['func1', $6];}
+ if (defined($7)) {return ['special', $7];}
+ if (defined($8)) {return ['varname', $8];}
+ if (defined($9)) {return ['numberE', $9];}
+ if (defined($10)) {return ['number', $10];}
+ }
+ else {
+ push @{$self->{posarray}}, [$p1, undef];
+ return undef;
+ }
+}
+
+sub parse {
+ my $self = shift;
+ $self->{parseerror} = "";
+ $self->{posarray} = [];
+ $self->{parseresult} = ['top', undef];
+ my (@backtrace) = (\$self->{parseresult});
+ my (@pushback) = ();
+
+ my $currentref = \$self->{parseresult}->[1];
+ my $curenttok;
+
+ my $sstring = shift;
+ $self->inittokenizer($sstring);
+ $currenttok = $self->nexttoken;
+ if (!$currenttok) {
+ if ($self->{string} =~ m/\G$/g) {
+ return $self->error("empty");
+ } else {
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Illegal character at position $position", $mark);
+ }
+ }
+ # so I can assume we got a token
+ local $_;
+ while ($currenttok) {
+ $_ = $currenttok->[0];
+ /binop1/ && do {
+ # check if we have a binary or unary operation here.
+ if (defined(${$currentref})) {
+ # binary - walk up the tree until we hit an open paren or the top
+ while (${$currentref}->[0] !~ /^(openp|top)/) {
+ $currentref = pop @backtrace;
+ }
+ my $index = ((${$currentref}->[0] eq 'top')?1:3);
+ ${$currentref}->[$index] = ['binop1', $currenttok->[1],
+ ${$currentref}->[$index], undef];
+ push @backtrace, $currentref;
+ push @backtrace, \${$currentref}->[$index];
+ $currentref = \${$currentref}->[$index]->[3];
+ } else {
+ # unary
+ ${$currentref} = ['unop1', $currenttok->[1], undef];
+ push @backtrace, $currentref;
+ $currentref = \${$currentref}->[2];
+ }
+ };
+ /binop2/ && do {
+ if (defined(${$currentref})) {
+ # walk up the tree until an open paren, the top, binop1 or unop1
+ # I decide arbitrarily that -3*4 should be parsed as -(3*4)
+ # instead of as (-3)*4. Not that it makes a difference.
+
+ while (${$currentref}->[0] !~ /^(openp|top|binop1)/) {
+ $currentref = pop @backtrace;
+ }
+ my $a = ${$currentref}->[0];
+ my $index = (($a eq 'top')?1:3);
+ ${$currentref}->[$index] = ['binop2', $currenttok->[1],
+ ${$currentref}->[$index], undef];
+ push @backtrace, $currentref;
+ push @backtrace, \${$currentref}->[$index];
+ $currentref = \${$currentref}->[$index]->[3];
+ } else {
+ # Error
+ my($mark) = pop @{$self->{posarray}};
+ my $position =1+$mark->[0];
+ return $self->error("Didn't expect " . $currenttok->[1] .
+ " at position $position" , $mark);
+ }
+ };
+ /binop3/ && do {
+ if (defined(${$currentref})) {
+ # walk up the tree until we need to stop
+ # Note that the right-associated nature of ^ means we need to
+ # stop walking backwards when we hit a ^ as well.
+ while (${$currentref}->[0] !~ /^(openp|top|binop[123]|unop1)/) {
+ $currentref = pop @backtrace;
+ }
+ my $a = ${$currentref}->[0];
+ my $index = ($a eq 'top')?1:($a eq 'unop1')?2:3;
+ ${$currentref}->[$index] = ['binop3', $currenttok->[1],
+ ${$currentref}->[$index], undef];
+ push @backtrace, $currentref;
+ push @backtrace, \${$currentref}->[$index];
+ $currentref = \${$currentref}->[$index]->[3];
+ } else {
+ # Error
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Didn't expect " . $currenttok->[1] .
+ " at position $position", $mark);
+ }
+ };
+ /openp/ && do {
+ if (defined(${$currentref})) {
+ # we weren't expecting this - must be implicit
+ # multiplication.
+ push @pushback, $currenttok;
+ $currenttok = ['binop2', 'implicit'];
+ next;
+ } else {
+ my($me) = pop @{$self->{posarray}};
+ ${$currentref} = [$currenttok->[0], $currenttok->[1], $me, undef];
+ push @backtrace, $currentref;
+ $currentref = \${$currentref}->[3];
+ }
+ };
+ /func1/ && do {
+ if (defined(${$currentref})) {
+ # we weren't expecting this - must be implicit
+ # multiplication.
+ push @pushback, $currenttok;
+ $currenttok = ['binop2', 'implicit'];
+ next;
+ } else {
+ # just like a unary operator
+ ${$currentref} = [$currenttok->[0], $currenttok->[1], undef];
+ push @backtrace, $currentref;
+ $currentref = \${$currentref}->[2];
+ }
+ };
+ /closep/ && do {
+ if (defined(${$currentref})) {
+ # walk up the tree until we need to stop
+ while (${$currentref}->[0] !~ /^(openp|top)/) {
+ $currentref = pop @backtrace;
+ }
+ my $a = ${$currentref}->[0];
+ if ($a eq 'top') {
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Unmatched close " . $currenttok->[1] .
+ " at position $position", $mark);
+ } elsif ($close{${$currentref}->[1]} ne $currenttok->[1]) {
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Mismatched parens at position $position"
+ , ${$currentref}->[2], $mark);
+ } else {
+ ${$currentref}->[0] = 'closep';
+ ${$currentref}->[2] = pop @{${$currentref}};
+ }
+ } else {
+ # Error - something like (3+4*)
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Premature close " . $currenttok->[1] .
+ " at position $position", $mark);
+ }
+ };
+ /special|varname|numberE?/ && do {
+ if (defined(${$currentref})) {
+ # we weren't expecting this - must be implicit
+ # multiplication.
+ push @pushback, $currenttok;
+ $currenttok = ['binop2', 'implicit'];
+ next;
+ } else {
+ ${$currentref} = [$currenttok->[0], $currenttok->[1]];
+ }
+ };
+ if (@pushback) {
+ $currenttok = pop @pushback;
+ } else {
+ $currenttok = $self->nexttoken;
+ }
+ }
+ # ok, we stopped parsing. Now we need to see why.
+ if ($self->{parseresult}->[0] eq 'top') {
+ $self->{parseresult} = $self->arraytoexpr($self->{parseresult}->[1]);
+ } else {
+ return $self->error("Internal consistency error; not at top when done");
+ }
+ if ($self->{string} =~ m/\G\s*$/g) {
+ if (!defined(${$currentref})) {
+ $self->{string} .= " ";
+ return $self->error("I was expecting more at the end of the line",
+ [length($self->{string})-1, length($self->{string})]);
+ } else {
+ # check that all the parens were closed
+ while (@backtrace) {
+ $currentref = pop @backtrace;
+ if (${$currentref}->[0] eq 'openp') {
+ my($mark) = ${$currentref}->[2];
+ my $position = 1+$mark->[0];
+ return $self->error("Unclosed parentheses beginning at position $position"
+ , $mark);
+ }
+ }
+ # Ok, we must really have parsed something
+ return $self->{parseresult};
+ }
+ } else {
+ my($mark) = pop @{$self->{posarray}};
+ my $position = 1+$mark->[0];
+ return $self->error("Illegal character at position $position",$mark);
+ }
+}
+
+sub arraytoexpr {
+ my ($self) = shift;
+ return Expr->fromarray(@_);
+}
+
+sub error {
+ my($self, $errstr, @markers) = @_;
+# print STDERR Data::Dumper->Dump([\@markers],
+# ['$markers']);
+ $self->{parseerror} = $errstr;
+ my($htmledstring) = '<tt class="parseinput">';
+ my($str) = $self->{string};
+# print STDERR Data::Dumper->Dump([$str], ['$str']);
+ my($lastpos) = 0;
+ $str =~ s/ /\240/g;
+ while(@markers) {
+ my($ref) = shift @markers;
+ my($pos1) = $ref->[0];
+ my($pos2) = $ref->[1];
+ if (!defined($pos2)) {$pos2 = $pos1+1;}
+ $htmledstring .= encode_entities(substr($str,$lastpos,$pos1-$lastpos)) .
+ '<b class="parsehilight">' .
+ encode_entities(substr($str,$pos1,$pos2-$pos1)) .
+ '</b>';
+ $lastpos = $pos2;
+ }
+# print STDERR Data::Dumper->Dump([$str, $htmledstring, $lastpos],
+# ['$str', '$htmledstring', '$lastpos']);
+ $htmledstring .= encode_entities(substr($str,$lastpos));
+ $htmledstring .= '</tt>';
+# $self->{htmlerror} = '<p class="parseerr">' . "\n" .
+# '<span class="parsedesc">' .
+# encode_entities($errstr) . '</span><br>' . "\n" .
+# $htmledstring . "\n" . '</p>' . "\n";
+ $self->{htmlerror} = $htmledstring ;
+ $self->{htmlerror} = 'empty' if $errstr eq 'empty';
+ $self->{error_msg} = $errstr;
+
+# warn $errstr . "\n";
+ return undef;
+}
+
+sub tostring {
+ my ($self) = shift;
+ return $self->{parseresult}->tostring(@_);
+}
+
+sub tolatex {
+ my ($self) = shift;
+ return $self->{parseresult}->tolatex(@_);
+}
+
+sub tolatexstring { return tolatex(@_);}
+
+sub exprtolatexstr {
+ return exprtolatex(@_);
+}
+
+sub exprtolatex {
+ my($expr) = shift;
+ my($exprobj);
+ if ((ref $expr) eq 'ARRAY') {
+ $exprobj = Expr->new(@$expr);
+ } else {
+ $exprobj = $expr;
+ }
+ return $exprobj->tolatex();
+}
+
+sub exprtostr {
+ my($expr) = shift;
+ my($exprobj);
+ if ((ref $expr) eq 'ARRAY') {
+ $exprobj = Expr->new(@$expr);
+ } else {
+ $exprobj = $expr;
+ }
+ return $exprobj->tostring();
+}
+
+sub normalize {
+ my ($self, $degree) = @_;
+ $self->{parseresult} = $self->{parseresult}->normalize($degree);
+}
+
+sub normalize_expr {
+ my($expr, $degree) = @_;
+ my($exprobj);
+ if ((ref $expr) eq 'ARRAY') {
+ $exprobj = Expr->new(@$expr);
+ } else {
+ $exprobj = $expr;
+ }
+ return $exprobj->normalize($degree);
+}
+
+package AlgParserWithImplicitExpand;
+@ISA=qw(AlgParser);
+
+sub arraytoexpr {
+ my ($self) = shift;
+ my ($foo) = ExprWithImplicitExpand->fromarray(@_);
+# print STDERR Data::Dumper->Dump([$foo],['retval']);
+ return $foo;
+}
+
+package Expr;
+
+sub new {
+ my($class) = shift;
+ my(@args) = @_;
+ my($ret) = [@args];
+ return (bless $ret, $class);
+}
+
+sub head {
+ my($self) = shift;
+ return ($self->[0]);
+}
+
+
+sub normalize {
+#print STDERR "normalize\n";
+#print STDERR Data::Dumper->Dump([@_]);
+
+ my($self, $degree) = @_;
+ my($class) = ref $self;
+ $degree = $degree || 0;
+ my($type, @args) = @$self;
+ local $_;
+ $_ = $type;
+ my ($ret) = [$type, @args];
+
+
+ if(/closep/) {
+ $ret = $args[1]->normalize($degree);
+ } elsif (/unop1/) {
+ $ret = $class->new($type, $args[0], $args[1]->normalize($degree));
+ } elsif (/binop/) {
+ $ret = $class->new($type, $args[0], $args[1]->normalize($degree),
+ $args[2]->normalize($degree));
+ } elsif (/func1/) {
+ $args[0] =~ s/^arc/a/;
+ $ret = $class->new($type, $args[0], $args[1]->normalize($degree));
+ }
+
+
+ if ($degree < 0) {return $ret;}
+
+
+ ($type, @args) = @$ret;
+ $ret = $class->new($type, @args);
+ $_ = $type;
+ if (/binop1/ && ($args[2]->[0] =~ 'unop1')) {
+ my($h1, $h2) = ($args[0], $args[2]->[1]);
+ my($s1, $s2) = ($h1 eq '-', $h2 eq '-');
+ my($eventual) = ($s1==$s2);
+ if ($eventual) {
+ $ret = $class->new('binop1', '+', $args[1], $args[2]->[2] );
+ } else {
+ $ret = $class->new('binop1', '-', $args[1], $args[2]->[2] );
+ }
+ } elsif (/binop2/ && ($args[1]->[0] =~ 'unop1')) {
+ $ret = $class->new('unop1', '-',
+ $class->new($type, $args[0], $args[1]->[2],
+ $args[2])->normalize($degree) );
+ } elsif (/binop[12]/ && ($args[2]->[0] eq $type) &&
+ ($args[0] =~ /[+*]/)) {
+# Remove frivolous right-association
+# For example, fix 3+(4-5) or 3*(4x)
+ $ret = $class->new($type, $args[2]->[1],
+ $class->new($type, $args[0], $args[1],
+ $args[2]->[2])->normalize($degree),
+ $args[2]->[3]);
+ } elsif (/unop1/ && ($args[0] eq '+')) {
+ $ret = $args[1];
+ } elsif (/unop1/ && ($args[1]->[0] =~ 'unop1')) {
+ $ret = $args[1]->[2];
+ }
+ if ($degree > 0) {
+ }
+ return $ret;
+}
+
+sub tostring {
+# print STDERR "Expr::tostring\n";
+# print STDERR Data::Dumper->Dump([@_]);
+ my($self) = shift;
+ my($type, @args) = @$self;
+ local $_;
+ $_ = $type;
+ /binop1/ && do {
+ my ($p1, $p2) = ('','');
+ if ($args[2]->[0] eq 'binop1') {($p1,$p2)=qw{ ( ) };}
+ return ($args[1]->tostring() . $args[0] . $p1 .
+ $args[2]->tostring() . $p2);
+ };
+ /unop1/ && do {
+ my ($p1, $p2) = ('','');
+ if ($args[1]->[0] =~ /binop1/) {($p1,$p2)=qw{ ( ) };}
+ return ($args[0] . $p1 . $args[1]->tostring() . $p2);
+ };
+ /binop2/ && do {
+ my ($p1, $p2, $p3, $p4)=('','','','');
+ if ($args[0] =~ /implicit/) {$args[0] = ' ';}
+ if ($args[1]->[0] =~ /binop1/) {($p1,$p2)=qw{ ( ) };}
+# if ($args[2]->[0] =~ /binop[12]/) {($p3,$p4)=qw{ ( ) };}
+ if ($args[2]->[0] =~ /binop[12]|unop1/) {($p3,$p4)=qw{ ( ) };}
+ return ($p1 . $args[1]->tostring() . $p2 . $args[0] . $p3 .
+ $args[2]->tostring() . $p4);
+ };
+ /binop3/ && do {
+ my ($p1, $p2, $p3, $p4)=('','','','');
+# if ($args[1]->[0] =~ /binop[123]|numberE/) {($p1,$p2)=qw{ ( ) };}
+ if ($args[1]->[0] =~ /binop[123]|unop1|numberE/) {($p1,$p2)=qw{ ( ) };}
+# if ($args[2]->[0] =~ /binop[12]|numberE/) {($p3,$p4)=qw{ ( ) };}
+ if ($args[2]->[0] =~ /binop[12]|unop1|numberE/) {($p3,$p4)=qw{ ( ) };}
+ return ($p1 . $args[1]->tostring() . $p2 . $args[0] . $p3 .
+ $args[2]->tostring() . $p4);
+ };
+ /func1/ && do {
+ return ($args[0] . '(' . $args[1]->tostring() . ')');
+ };
+ /special|varname|numberE?/ && return $args[0];
+ /closep/ && do {
+ my(%close) = %AlgParser::close;
+
+
+
+ return ($args[0] . $args[1]->tostring() . $close{$args[0]});
+ };
+}
+
+sub tolatex {
+ my($self) = shift;
+ my($type, @args) = @$self;
+ local $_;
+ $_ = $type;
+ /binop1/ && do {
+ my ($p1, $p2) = ('','');
+ if ($args[2]->[0] eq 'binop1') {($p1,$p2)=qw{ \left( \right) };}
+ return ($args[1]->tolatex() . $args[0] . $p1 .
+ $args[2]->tolatex() . $p2);
+ };
+ /unop1/ && do {
+ my ($p1, $p2) = ('','');
+ if ($args[1]->[0] =~ /binop1/) {($p1,$p2)=qw{ \left( \right) };}
+ return ($args[0] . $p1 . $args[1]->tolatex() . $p2);
+ };
+ /binop2/ && do {
+ my ($p1, $p2, $p3, $p4) = ('','','','');
+ if ($args[0] =~ /implicit/) {
+ if ( (($args[1]->head eq qq(number)) &&
+ ($args[2]->head eq qq(number))) ||
+ (($args[1]->head eq qq(binop2)) &&
+ ($args[1]->[2]->head eq qq(number))) ) {
+ $args[0] = '\\,';
+ } else {
+ $args[0] = ' ';
+ }
+ }
+ if ($args[1]->[0] =~ /binop1|numberE/)
+ {($p1,$p2)=qw{ \left( \right) };}
+ # if ($args[2]->[0] =~ /binop[12]|numberE/)
+ if ($args[2]->[0] =~ /binop[12]|numberE|unop1/)
+ {($p3,$p4)=qw{ \left( \right) };}
+ if ($args[0] eq '/'){
+ return('\frac{' . $p1 . $args[1]->tolatex() . $p2 . '}'.
+ '{' . $p3 . $args[2]->tolatex() . $p4 . '}' );
+ }
+ else{
+ return ($p1 . $args[1]->tolatex() . $p2 . $args[0] . $p3 .
+ $args[2]->tolatex() . $p4);
+ }
+ };
+ /binop3/ && do {
+ my ($p1, $p2, $p3, $p4)=('','','','');
+# if ($args[1]->[0] =~ /binop[123]|numberE/) {($p1,$p2)=qw{ \left( \right) };}
+ if ($args[1]->[0] =~ /binop[123]|unop1|numberE/) {($p1,$p2)=qw{ \left( \right) };}
+# Not necessary in latex
+# if ($args[2]->[0] =~ /binop[12]/) {($p3,$p4)=qw{ \left( \right) };}
+ return ($p1 . $args[1]->tolatex() . $p2 . "^{" . $p3 .
+ $args[2]->tolatex() . $p4 . "}");
+ };
+ /func1/ && do {
+ my($p1,$p2);
+ if($args[0] eq "sqrt"){($p1,$p2)=qw{ \left{ \right} };}
+ else {($p1,$p2)=qw{ \left( \right) };}
+
+ #
+ # DPVC -- 2003/03/31
+ # added missing trig functions
+ #
+ #$specialfunc = '(?:abs|logten|asin|acos|atan|sech|sgn|step|fact)';
+ $specialfunc = '(?:abs|logten|a(?:sin|cos|tan|sec|csc|cot)h?|sgn|step|fact)';
+ #
+ # End DPVC
+ #
+
+ if ($args[0] =~ /$specialfunc/) {
+ return ('\mbox{' . $args[0] .'}'. $p1 . $args[1]->tolatex() . $p2);
+ }
+ else {
+ return ('\\' . $args[0] . $p1 . $args[1]->tolatex() . $p2);
+ }
+ };
+ /special/ && do {
+ if ($args[0] eq 'pi') {return '\pi';} else {return $args[0];}
+ };
+ /varname|(:?number$)/ && return $args[0];
+ /numberE/ && do {
+ $args[0] =~ m/($AlgParser::numberplain)E([-+]?\d+)/;
+ return ($1 . '\times 10^{' . $2 . '}');
+ };
+ /closep/ && do {
+ my($backslash) = '';
+ my(%close) = %AlgParser::close;
+ if ($args[0] eq '{') {$backslash = '\\';}
+#This is for editors to match: }
+ return ('\left' . $backslash . $args[0] . $args[1]->tolatex() .
+ '\right' . $backslash . $close{$args[0]});
+ };
+}
+
+sub fromarray {
+ my($class) = shift;
+ my($expr) = shift;
+ if ((ref $expr) ne qq{ARRAY}) {
+ die "Program error; fromarray not passed an array ref.";
+ }
+ my($type, @args) = @$expr;
+ foreach my $i (@args) {
+ if (ref $i) {
+ $i = $class->fromarray($i);
+ }
+ }
+ return $class->new($type, @args);
+}
+
+package ExprWithImplicitExpand;
+@ISA=qw(Expr);
+
+
+sub tostring {
+# print STDERR "ExprWIE::tostring\n";
+# print STDERR Data::Dumper->Dump([@_]);
+ my ($self) = shift;
+
+ my($type, @args) = @$self;
+
+ if (($type eq qq(binop2)) && ($args[0] eq qq(implicit))) {
+ my ($p1, $p2, $p3, $p4)=('','','','');
+ if ($args[1]->head =~ /binop1/) {($p1,$p2)=qw{ ( ) };}
+# if ($args[2]->head =~ /binop[12]/) {($p3,$p4)=qw{ ( ) };}
+ if ($args[2]->head =~ /binop[12]|unop1/) {($p3,$p4)=qw{ ( ) };}
+ return ($p1 . $args[1]->tostring() . $p2 . '*' . $p3 .
+ $args[2]->tostring() . $p4);
+ } else {
+ return $self->SUPER::tostring(@_);
+ }
+}
View
17 filter/algebra/algebra2tex.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/perl
+
+use lib '.';
+use AlgParser;
+
+my $parser = new AlgParserWithImplicitExpand;
+my $ret;
+
+$ret = $parser -> parse($ARGV[0]);
+if ( ref($ret) ) {
+ $parser -> tostring();
+ $parser -> normalize();
+ print $parser -> tolatex();
+} else {
+ print $parser->{htmlerror};
+}
+
View
194 filter/algebra/algebra_filter.php
@@ -0,0 +1,194 @@
+<?PHP
+/////////////////////////////////////////////////////////////////////////////
+// //
+// NOTICE OF COPYRIGHT //
+// //
+// Moodle - Filter for converting simple caclculator-type algebraic //
+// expressions to cached gif images //
+// //
+// Copyright (C) 2004 Zbigniew Fiedorowicz fiedorow@math.ohio-state.edu //
+// Originally based on code provided by Bruno Vernier bruno@vsbeducation.ca//
+// This program is free software; you can redistribute it and/or modify //
+// it under the terms of the GNU General Public License as published by //
+// the Free Software Foundation; either version 2 of the License, or //
+// (at your option) any later version. //
+// //
+// This program is distributed in the hope that it will be useful, //
+// but WITHOUT ANY WARRANTY; without even the implied warranty of //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
+// GNU General Public License for more details: //
+// //
+// http://www.gnu.org/copyleft/gpl.html //
+// //
+/////////////////////////////////////////////////////////////////////////////
+//-------------------------------------------------------------------------
+// NOTE: This Moodle text filter converts algebraic expressions delimited
+// by either @@...@@ or by <algebra...>...</algebra> tags
+// first converts it to TeX using WeBWorK algebra parser Perl library
+// AlgParser.pm, part of the WeBWorK distribution obtained from
+// http://webhost.math.rochester.edu/downloadwebwork/
+// then converts the TeX to gif images using
+// mimetex.cgi obtained from http://www.forkosh.com/mimetex.html authored by
+// John Forkosh john@forkosh.com. The mimetex.cgi ELF binary compiled for Linux i386
+// as well as AlgParser.pm are included with this distribution.
+// Note that there may be patent restrictions on the production of gif images
+// in Canada and some parts of Western Europe and Japan until July 2004.
+//-------------------------------------------------------------------------
+// You will then need to edit your moodle/config.php to invoke mathml_filter.php
+//-------------------------------------------------------------------------
+
+
+/// Edit these lines to correspond to your installation
+// File path to the directory where mathml_filter.php resides
+ $CFG->algebrafilterdir = "filter/algebra";
+
+
+/// These lines are important - the variable must match the name
+/// of the actual function below
+ $textfilter_function='algebra_filter';
+
+ if (function_exists($textfilter_function)) {
+ return;
+ }
+
+
+function string_file_picture_algebra($imagefile, $tex= "", $height="", $width="") {
+ // Given the path to a picture file in a course, or a URL,
+ // this function includes the picture in the page.
+ global $CFG;
+
+ $output = "";
+ if ($tex) {
+ $tex = str_replace('&','&amp;',$tex);
+ $tex = str_replace('<','&lt;',$tex);
+ $tex = str_replace('>','&gt;',$tex);
+ $tex = str_replace('"','&quot;',$tex);
+ $tex = str_replace("\'",'&#39;',$tex);
+ $title = "title=\"$tex\"";
+ }
+ if ($height) {
+ $height = "height=\"$height\"";
+ }
+ if ($width) {
+ $width = "width=\"$width\"";
+ }
+ if ($imagefile) {
+ $output .= "<img border=\"0\" $title $height $width src=\"";
+ if ($CFG->slasharguments) { // Use this method if possible for better caching
+ $output .= "$CFG->wwwroot/$CFG->algebrafilterdir/pix.php/$imagefile";
+ } else {
+ $output .= "$CFG->wwwroot/$CFG->algebrafilterdir/pix.php?file=$imagefile";
+ }
+ $output .= "\" />";
+ } else {
+ $output .= "Error: must pass URL or course";
+ }
+ return $output;
+}
+
+
+function algebra_filter ($courseid, $text) {
+
+ global $CFG;
+
+ /// Do a quick check using stripos to avoid unnecessary wor
+ if (!preg_match('/<algebra/i',$text) && !strstr($text,'@@')) {
+ return $text;
+ }
+
+# //restrict filtering to forum 130 (Maths Tools on moodle.org)
+# $scriptname = $_SERVER['SCRIPT_NAME'];
+# if (!strstr($scriptname,'/forum/')) {
+# return $text;
+# }
+# if (strstr($scriptname,'post.php')) {
+# $parent = forum_get_post_full($_GET['reply']);
+# $discussion = get_record("forum_discussions","id",$parent->discussion);
+# } else if (strstr($scriptname,'discuss.php')) {
+# $discussion = get_record("forum_discussions","id",$_GET['d'] );
+# } else {
+# return $text;
+# }
+# if ($discussion->forum != 130) {
+# return $text;
+# }
+
+
+ $text .= ' ';
+
+ preg_match_all('/@(@@+)([^@])/',$text,$matches);
+ for ($i=0;$i<count($matches[0]);$i++) {
+ $replacement = str_replace('@','&#x00040;',$matches[1][$i]).$matches[2][$i];
+ $text = str_replace($matches[0][$i],$replacement,$text);
+ }
+
+ if (isadmin()) { error_reporting (E_ALL); }; //for debugging
+
+ // <algebra> some algebraic input expression </algebra>
+ // or @@ some algebraic input expression @@
+
+ preg_match_all('/<algebra>(.+?)<\/algebra>|@@(.+?)@@/is', $text, $matches);
+ for ($i=0; $i<count($matches[0]); $i++) {
+ $algebra = $matches[1][$i] . $matches[2][$i];
+ $md5 = md5($algebra);
+ $filename = $md5 . ".gif";
+ if (! $texcache = get_record("cache_filters","filter","algebra", "md5key", $md5)) {
+ $algebra = str_replace('&lt;','<',$algebra);
+ $algebra = str_replace('&gt;','>',$algebra);
+ $algebra = str_replace('<>','#',$algebra);
+ $algebra = str_replace('<=','%',$algebra);
+ $algebra = str_replace('>=','!',$algebra);
+ $algebra = preg_replace('!\r\n?!',' ',$algebra);
+ if ( (PHP_OS == "WINNT") || (PHP_OS == "WIN32") || (PHP_OS == "Windows") ) {
+ $algebra = "\"". str_replace('"','\"',$algebra) . "\"";
+ $cmd = "cd $CFG->dirroot/$CFG->algebrafilterdir & algebra2tex.pl $algebra";
+ } else {
+ $algebra = escapeshellarg($algebra);
+ $cmd = "cd $CFG->dirroot/$CFG->algebrafilterdir; ./algebra2tex.pl $algebra";
+ }
+ $texexp = `$cmd`;
+ if (preg_match('/parsehilight/',$texexp)) {
+ $text = str_replace( $matches[0][$i],"<b>Syntax error:</b> " . $texexp,$text);
+ } else {
+ $texexp = str_replace('#','\not= ',$texexp);
+ $texexp = str_replace('%','\leq ',$texexp);
+ $texexp = str_replace('!','\geq ',$texexp);
+ $texexp = str_replace('\left{','{',$texexp);
+ $texexp = str_replace('\right}','}',$texexp);
+ $texexp = str_replace('\fun',' ',$texexp);
+ $texexp = str_replace('infty','\infty',$texexp);
+ $texexp = str_replace('\mbox{logten}','\mbox{log}_{10}',$texexp);
+ $texexp = str_replace('\mbox{acos}','\mbox{cos}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{asin}','\mbox{sin}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{atan}','\mbox{tan}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{asec}','\mbox{sec}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{acsc}','\mbox{csc}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{acot}','\mbox{cot}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{acosh}','\mbox{cosh}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{asinh}','\mbox{sinh}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{atanh}','\mbox{tanh}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{asech}','\mbox{sech}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{acsch}','\mbox{csch}^{-1}',$texexp);
+ $texexp = str_replace('\mbox{acoth}','\mbox{coth}^{-1}',$texexp);
+ $texexp = preg_replace('/\\\sqrt{(.+?),(.+?)}/s','\sqrt['. "\$2]{\$1}",$texexp);
+ $texexp = preg_replace('/\\\log\\\left\((.+?),(.+?)\\\right\)/s','\log_{'. "\$2}\\left(\$1\\right)",$texexp);
+ $texexp = preg_replace('/(\\\cos|\\\sin|\\\tan|\\\sec|\\\csc|\\\cot)([h]*)\\\left\((.+?),(.+?)\\\right\)/s',"\$1\$2^{". "\$4}\\left(\$3\\right)",$texexp);
+ $texexp = preg_replace('/\\\int\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\int_'. "{\$2}^{\$3}\$1 ",$texexp);
+ $texexp = preg_replace('/\\\int\\\left\((.+?d[a-z])\\\right\)/s','\int '. "\$1 ",$texexp);
+ $texexp = preg_replace('/\\\lim\\\left\((.+?),(.+?),(.+?)\\\right\)/s','\lim_'. "{\$2\\to \$3}\$1 ",$texexp);
+ $texcache->filter = 'algebra';
+ $texcache->version = 1;
+ $texcache->md5key = $md5;
+ $texcache->rawtext = addslashes($texexp);
+ $texcache->timemodified = time();
+ insert_record("cache_filters",$texcache);
+ $text = str_replace( $matches[0][$i], string_file_picture_algebra($filename, $texexp), $text);
+ }
+ } else {
+ $text = str_replace( $matches[0][$i], string_file_picture_algebra($filename, $texcache->rawtext), $text);
+ }
+ }
+ return $text;
+}
+
+?>
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BIN  filter/algebra/mimetex.darwin
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BIN  filter/algebra/mimetex.linux
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81 filter/algebra/pix.php
@@ -0,0 +1,81 @@
+<?PHP // $Id$
+ // This function fetches math. images from the data directory
+ // If not, it obtains the corresponding TeX expression from the cache_tex db table
+ // and uses mimeTeX to create the image file
+
+ $nomoodlecookie = true; // Because it interferes with caching
+
+ require_once("../../config.php");
+
+ $CFG->algebrafilterdir = "filter/algebra";
+ $CFG->algebraimagedir = "filter/algebra";
+
+ error_reporting(E_ALL);
+
+ $lifetime = 86400;
+ if (isset($file)) { // workaround for situations where / syntax doesn't work
+ $pathinfo = '/' . $file;
+ } else {
+ $pathinfo = get_slash_arguments("pix.php");
+ }
+
+ if (! $args = parse_slash_arguments($pathinfo)) {
+ error("No valid arguments supplied");
+ }
+
+ $numargs = count($args);
+
+ if ($numargs == 1) {
+ $image = $args[0];
+ $pathname = "$CFG->dataroot/$CFG->algebraimagedir/$image";
+ $filetype = "image/gif";
+ } else {
+ error("No valid arguments supplied");
+ }
+
+
+ if (!file_exists($pathname)) {
+ $md5 = str_replace('.gif','',$image);
+ if ($texcache = get_record("cache_filters", "filter", "algebra", "md5key", $md5)) {
+ if (!file_exists("$CFG->dataroot/$CFG->algebraimagedir")) {
+ make_upload_directory($CFG->algebraimagedir);
+ }
+
+ $texexp = $texcache->rawtext;
+ $texexp = str_replace('&lt;','<',$texexp);
+ $texexp = str_replace('&gt;','>',$texexp);
+ $texexp = preg_replace('!\r\n?!',' ',$texexp);
+ $texexp = '\Large ' . $texexp;
+ switch (PHP_OS) {
+ case "Linux":
+ system("$CFG->dirroot/$CFG->algebrafilterdir/mimetex.linux -e $pathname ". escapeshellarg($texexp) );
+ break;
+ case "WINNT":
+ case "WIN32":
+ case "Windows":
+ $texexp = str_replace('"','\"',$texexp);
+ system("$CFG->dirroot/$CFG->algebrafilterdir/mimetex.exe -e $pathname \"$texexp\"");
+ break;
+ case "Darwin":
+ system("$CFG->dirroot/$CFG->algebrafilterdir/mimetex.darwin -e $pathname ". escapeshellarg($texexp) );
+ break;
+ }
+ }
+ }
+
+ if (file_exists($pathname)) {
+ $lastmodified = filemtime($pathname);
+ header("Last-Modified: " . gmdate("D, d M Y H:i:s", $lastmodified) . " GMT");
+ header("Expires: " . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT");
+ header("Cache-control: max_age = $lifetime"); // a day
+ header("Pragma: ");
+ header("Content-disposition: inline; filename=$image");
+ header("Content-length: ".filesize($pathname));
+ header("Content-type: $filetype");
+ readfile("$pathname");
+ } else {
+ echo "Image not found!";
+ }
+
+ exit;
+?>
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