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1 : sh002i 2558 package Parser;
2 :     my $pkg = "Parser";
3 :     use strict;
4 :    
5 : dpvc 2678 #
6 :     # Map class names to packages (added to Context, and
7 :     # can be overriden to customize the parser)
8 :     #
9 :     our %class = {Formula => 'Parser::Formula'};
10 :    
11 : sh002i 2558 ##################################################
12 :     #
13 :     # Parse a string and create a new Parser object
14 :     # If the string is already a parsed object then copy the parse tree
15 :     # If it is a Value, make an appropriate tree for it.
16 :     #
17 :     sub new {
18 :     my $self = shift; my $class = ref($self) || $self;
19 :     my $string = shift;
20 : dpvc 2660 $string = Value::List->new($string,@_)
21 :     if scalar(@_) > 0 || ref($string) eq 'ARRAY';
22 : sh002i 2558 my $math = bless {
23 :     string => undef,
24 : dpvc 2576 tokens => [], tree => undef,
25 : sh002i 2558 variables => {}, values => {},
26 :     context => Parser::Context->current,
27 :     }, $class;
28 :     if (ref($string) =~ m/^(Parser|Value::Formula)/) {
29 :     my $tree = $string; $tree = $tree->{tree} if exists $tree->{tree};
30 :     $math->{tree} = $tree->copy($math);
31 : dpvc 2660 } elsif (Value::isValue($string)) {
32 : dpvc 2678 $math->{tree} = $math->{context}{parser}{Value}->new($math,$string);
33 : sh002i 2558 } else {
34 :     $math->{string} = $string;
35 :     $math->tokenize;
36 :     $math->parse;
37 :     }
38 :     return $math;
39 :     }
40 :    
41 :     sub copy {my $self = shift; $self->new($self)}
42 :    
43 :     ##################################################
44 :     #
45 :     # Break the string into tokens based on the patterns for the various
46 :     # types of objects.
47 :     #
48 :     sub tokenize {
49 :     my $self = shift; my $space;
50 :     my $tokens = $self->{tokens}; my $string = $self->{string};
51 :     my $tokenPattern = $self->{context}{pattern}{token};
52 :     @{$tokens} = (); $self->{error} = 0; $self->{message} = '';
53 :     $string =~ m/^\s*/gc; my $p0 = 0; my $p1;
54 :     while (pos($string) < length($string)) {
55 :     $p0 = pos($string);
56 :     if ($string =~ m/\G$tokenPattern/gc) {
57 :     $p1 = pos($string);
58 :     push(@{$tokens},['str',$1,$p0,$p1,$space]) if (defined($1));
59 :     push(@{$tokens},['fn',$2,$p0,$p1,$space]) if (defined($2));
60 :     push(@{$tokens},['const',$3,$p0,$p1,$space]) if (defined($3));
61 :     push(@{$tokens},['num',$4,$p0,$p1,$space]) if (defined($4));
62 :     push(@{$tokens},['op',$5,$p0,$p1,$space]) if (defined($5));
63 :     push(@{$tokens},['open',$6,$p0,$p1,$space]) if (defined($6));
64 :     push(@{$tokens},['close',$7,$p0,$p1,$space]) if (defined($7));
65 :     push(@{$tokens},['var',$8,$p0,$p1,$space]) if (defined($8));
66 :     } else {
67 : dpvc 2592 push(@{$tokens},['error',substr($string,$p0,1),$p0,$p0+1]);
68 : sh002i 2558 $self->{error} = 1;
69 :     last;
70 :     }
71 :     $space = ($string =~ m/\G\s+/gc);
72 :     }
73 :     }
74 :    
75 :     ##################################################
76 :     #
77 :     # Parse the token list to produce the expression tree. This does syntax checks
78 :     # and reports "compile-time" errors.
79 :     #
80 :     # Start with a stack that has a single entry (an OPEN object for the expression)
81 :     # For each token, try to add that token to the tree.
82 :     # After all tokens have been finished, add a CLOSE object for the initial OPEN
83 :     # and save the complete tree
84 :     #
85 :     sub parse {
86 :     my $self = shift;
87 :     $self->{tree} = undef; $self->{error} = 0;
88 :     $self->{stack} = [{type => 'open', value => 'start'}];
89 :     foreach my $ref (@{$self->{tokens}}) {
90 :     $self->{ref} = $ref; $self->{space} = $ref->[4];
91 :     for ($ref->[0]) {
92 :     /open/ and do {$self->Open($ref->[1]); last};
93 :     /close/ and do {$self->Close($ref->[1],$ref); last};
94 :     /op/ and do {$self->Op($ref->[1],$ref); last};
95 :     /num/ and do {$self->Num($ref->[1]); last};
96 :     /const/ and do {$self->Const($ref->[1]); last};
97 :     /var/ and do {$self->Var($ref->[1]); last};
98 :     /fn/ and do {$self->Fn($ref->[1]); last};
99 :     /str/ and do {$self->Str($ref->[1]); last};
100 : dpvc 2592 /error/ and do {$self->Error("Unexpected character '$ref->[1]'",$ref); last};
101 : sh002i 2558 }
102 :     return if ($self->{error});
103 :     }
104 :     $self->Close('start'); return if ($self->{error});
105 :     $self->{tree} = $self->{stack}->[0]->{value};
106 :     }
107 :    
108 :    
109 :     # Get the top or previous item of the stack
110 :     #
111 :     sub top {
112 :     my $self = shift; my $i = shift || 0;
113 :     return $self->{stack}->[$i-1];
114 :     }
115 :     sub prev {(shift)->top(-1)}
116 :    
117 :     #
118 :     # Push or pop the top of the stack
119 :     #
120 :     sub pop {pop(@{(shift)->{stack}})}
121 :     sub push {push(@{(shift)->{stack}},@_)}
122 :    
123 :     #
124 :     # Return the type of the top item
125 :     #
126 :     sub state {(shift)->top->{type}}
127 :    
128 :     #
129 :     # Report an error at a given possition (if possible)
130 :     #
131 :     sub Error {
132 :     my $self = shift; my $context = $self->{context};
133 :     my $message = shift; my $ref = shift; my $string;
134 :     if ($ref) {
135 :     $message .= "; see position ".($ref->[2]+1)." of formula";
136 :     $string = $self->{string};
137 :     $ref = [$ref->[2],$ref->[3]];
138 :     }
139 :     $context->setError($message,$string,$ref);
140 :     die $message . Value::getCaller();
141 :     }
142 :    
143 :     #
144 :     # Insert an implicit multiplication
145 : dpvc 2676 # (fix up the reference for spaces or juxtaposition)
146 : sh002i 2558 #
147 :     sub ImplicitMult {
148 :     my $self = shift;
149 : dpvc 2676 my $ref = $self->{ref}; my $iref = [@{$ref}];
150 :     $iref->[2]--; $iref->[3] = $iref->[2]+1;
151 :     $iref->[3]++ unless substr($self->{string},$iref->[2],1) eq ' ';
152 :     $self->Error("Can't perform implied multiplication in this context",$iref)
153 : dpvc 2657 unless $self->{context}{operators}{' '}{class};
154 : dpvc 2676 $self->Op(' ',$iref);
155 : sh002i 2558 $self->{ref} = $ref;
156 :     }
157 :    
158 :     #
159 :     # Push an operator onto the expression stack.
160 :     # We save the operator symbol, the precedence, etc.
161 :     #
162 :     sub pushOperator {
163 :     my $self = shift;
164 :     my ($op,$precedence,$reverse) = @_;
165 :     $self->push({
166 :     type => 'operator', ref => $self->{ref},
167 :     name => $op, precedence => $precedence, reverse => $reverse
168 :     });
169 :     }
170 :    
171 :     #
172 :     # Push an operand onto the expression stack.
173 :     #
174 :     sub pushOperand {
175 :     my $self = shift; my $value = shift;
176 :     $self->push({type => 'operand', ref => $self->{ref}, value => $value});
177 :     }
178 :    
179 :     ##################################################
180 :     #
181 :     # Handle an operator token
182 :     #
183 :     # Get the operator data from the context
184 :     # If the top of the stack is an operand
185 :     # If the operator is a left-associative unary operator
186 :     # Insert an implicit multiplication and save the operator
187 :     # Otherwise
188 :     # Complete any pending operations of higher precedence
189 :     # If the top item is still an operand
190 :     # If we have a (right associative) unary operator
191 :     # Apply it to the top operand
192 :     # Otherwise (binary operator)
193 :     # Convert the space operator to explicit multiplication
194 :     # Save the opertor on the stack
195 :     # Otherwise, (top is not an operand)
196 :     # If the operator is an explicit on or the top is a function
197 :     # Call Op again to report the error, or to apply
198 :     # the operator to the function (this happens when
199 :     # there is a function to a power, for example)
200 :     # Otherwise (top is not an operand)
201 :     # If this is a left-associative unary operator, save it on the stack
202 :     # Otherwise, if it is a left-associative operator that CAN be unary
203 :     # Save the unary version of the operator on the stack
204 :     # Otherwise, if the top item is a function
205 :     # If the operator can be applied to functions, save it on the stack
206 :     # Otherwise, report that the function is missing its inputs
207 :     # Otherwise, report the missing operand for this operator
208 :     #
209 :     sub Op {
210 :     my $self = shift; my $name = shift;
211 :     my $ref = $self->{ref} = shift;
212 :     my $context = $self->{context}; my $op = $context->{operators}{$name};
213 :     $op = $context->{operators}{$op->{space}} if $self->{space} && defined($op->{space});
214 :     if ($self->state eq 'operand') {
215 :     if ($op->{type} eq 'unary' && $op->{associativity} eq 'left') {
216 :     $self->ImplicitMult();
217 :     $self->pushOperator($name,$op->{precedence});
218 :     } else {
219 :     $self->Precedence($op->{precedence});
220 :     if ($self->state eq 'operand') {
221 :     if ($op->{type} eq 'unary') {
222 :     my $top = $self->pop;
223 : dpvc 2678 $self->pushOperand($context->{parser}{UOP}->new($self,$name,$top->{value},$ref));
224 : sh002i 2558 } else {
225 :     $name = $context->{operators}{' '}{string}
226 :     if $name eq ' ' or $name eq $context->{operators}{' '}{space};
227 :     $self->pushOperator($name,$op->{precedence});
228 :     }
229 :     } elsif ($ref || $self->state ne 'fn') {$self->Op($name,$ref)}
230 :     }
231 :     } else {
232 :     $name = 'u'.$name, $op = $context->{operators}{$name}
233 :     if ($op->{type} eq 'both' && defined $context->{operators}{'u'.$name});
234 :     if ($op->{type} eq 'unary' && $op->{associativity} eq 'left') {
235 :     $self->pushOperator($name,$op->{precedence});
236 :     } elsif ($self->state eq 'fn') {
237 :     if ($op->{leftf}) {
238 :     $self->pushOperator($name,$op->{precedence},1);
239 :     } else {
240 :     my $top = $self->top;
241 :     $self->Error("Function '$top->{name}' is missing its input(s)",$top->{ref});
242 :     }
243 :     } else {$self->Error("Missing operand before '$name'",$ref)}
244 :     }
245 :     }
246 :    
247 :     ##################################################
248 :     #
249 :     # Handle an open parenthesis
250 :     #
251 :     # If the top of the stack is an operand
252 :     # Check if the open paren is really a close paren (for when the open
253 :     # and close symbol are the same)
254 :     # Otherwise insert an implicit multiplication
255 :     # Save the open object on the stack
256 :     #
257 :     sub Open {
258 :     my $self = shift; my $type = shift;
259 :     my $paren = $self->{context}{parens}{$type};
260 :     if ($self->state eq 'operand') {
261 :     if ($type eq $paren->{close})
262 :     {$self->Close($type,$self->{ref}); return} else {$self->ImplicitMult()}
263 :     }
264 :     $self->push({type => 'open', value => $type, ref => $self->{ref}});
265 :     }
266 :    
267 :     ##################################################
268 :     #
269 :     # Handle a close parenthesis
270 :     #
271 :     # When the top stack object is
272 :     # An open parenthesis (that is empty):
273 :     # Get the data for the type of parentheses
274 :     # If the parentheses can be empty and the parentheses match
275 :     # Save the empty list
276 :     # Otherwise report a message appropriate to the type of parentheses
277 :     #
278 :     # An operand:
279 :     # Complete any pending operations, and stop if there was an error
280 :     # If the top is no longer an operand
281 :     # Call Close to report the error and return
282 :     # Get the item before the operand (an OPEN object), and its parenthesis type
283 :     # If the parens match
284 :     # Pop the operand off the stack
285 :     # If the parens can't be removed, or if the operand is a list
286 :     # Make the operand into a list object
287 :     # Replace the paren object with the operand
288 :     # If the parentheses are used for function calls and the
289 :     # previous stack object is a function call, do the function apply
290 :     # Otherwise report an appropriate error message
291 :     #
292 :     # A function:
293 :     # Report an error message about missing inputs
294 :     #
295 :     # An operator:
296 :     # Report the missing operation
297 :     #
298 :     sub Close {
299 :     my $self = shift; my $type = shift;
300 :     my $ref = $self->{ref} = shift;
301 : dpvc 2678 my $parser = $self->{context}{parser};
302 : sh002i 2558 my $parens = $self->{context}{parens};
303 :    
304 :     for ($self->state) {
305 :     /open/ and do {
306 :     my $top = $self->pop; my $paren = $parens->{$top->{value}};
307 :     if ($paren->{emptyOK} && $paren->{close} eq $type) {
308 : dpvc 2678 $self->pushOperand($parser->{List}->new($self,[],1,$paren))
309 : sh002i 2558 }
310 :     elsif ($type eq 'start') {$self->Error("Missing close parenthesis for '$top->{value}'",$top->{ref})}
311 :     elsif ($top->{value} eq 'start') {$self->Error("Extra close parenthesis '$type'",$ref)}
312 : dpvc 2660 else {$top->{ref}[3]=$ref->[3]; $self->Error("Empty parentheses",$top->{ref})}
313 : sh002i 2558 last;
314 :     };
315 :    
316 :     /operand/ and do {
317 :     $self->Precedence(0); return if ($self->{error});
318 :     if ($self->state ne 'operand') {$self->Close($type,$ref); return}
319 :     my $paren = $parens->{$self->prev->{value}};
320 :     if ($paren->{close} eq $type) {
321 :     my $top = $self->pop;
322 :     if (!$paren->{removable} || ($top->{value}->type eq "Comma")) {
323 :     $top = $top->{value};
324 :     $top = {type => 'operand', value =>
325 : dpvc 2678 $parser->{List}->new($self,[$top->makeList],$top->{isConstant},$paren,
326 : sh002i 2558 ($top->type eq 'Comma') ? $top->entryType : $top->typeRef,
327 :     ($type ne 'start') ? ($self->top->{value},$type) : () )};
328 :     }
329 :     $self->pop; $self->push($top);
330 :     $self->CloseFn() if ($paren->{function} && $self->prev->{type} eq 'fn');
331 :     } elsif ($paren->{formInterval} eq $type && $self->top->{value}->length == 2) {
332 :     my $top = $self->pop->{value}; my $open = $self->pop->{value};
333 :     $self->pushOperand(
334 : dpvc 2678 $parser->{List}->new($self,[$top->makeList],$top->{isConstant},
335 :     $paren,$top->entryType,$open,$type));
336 : sh002i 2558 } else {
337 :     my $prev = $self->prev;
338 :     if ($type eq "start") {$self->Error("Missing close parenthesis for '$prev->{value}'",$prev->{ref})}
339 :     elsif ($prev->{value} eq "start") {$self->Error("Extra close parenthesis '$type'",$ref)}
340 :     else {$self->Error("Mismatched parentheses: '$prev->{value}' and '$type'",$ref)}
341 :     return;
342 :     }
343 :     last;
344 :     };
345 :    
346 :     /fn/ and do {
347 :     my $top = $self->top;
348 :     $self->Error("Function '$top->{name}' is missing its input(s)",$top->{ref});
349 :     return;
350 :     };
351 :    
352 :     /operator/ and do {
353 :     my $top = $self->top(); my $name = $top->{name}; $name =~ s/^u//;
354 :     $self->Error("Missing operand after '$name'",$top->{ref});
355 :     return;
356 :     };
357 :     }
358 :     }
359 :    
360 :     ##################################################
361 :     #
362 :     # Handle any pending operations of higher precedence
363 :     #
364 :     # While the top stack item is an operand:
365 :     # When the preceding item is:
366 :     # An pending operator:
367 :     # Get the precedence of the operator (use the special right-hand prrecedence
368 :     # of there is one, otherwise use the general precedence)
369 :     # Stop processing if the current operator precedence is higher
370 :     # If the stacked operator is binary or if it is reversed (for function operators)
371 :     # Stop processing if the precedence is equal and we are right associative
372 :     # If the operand for the stacked operator is a function
373 :     # If the operation is ^(-1) (for inverses)
374 :     # Push the inverse function name
375 :     # Otherwise
376 :     # Reverse the order of the stack, so that the function can be applied
377 :     # to the next operand (it will be unreversed later)
378 :     # Otherwise (not a function, so an operand)
379 :     # Get the operands and binary operator off the stack
380 :     # If it is reversed (for functions), get the order right
381 :     # Save the result of the binary operation as an operand on the stack
382 :     # Otherwise (the stack contains a unary operator)
383 :     # Get the operator and operand off the stack
384 :     # Push the result of the unary operator as an operand on the stack
385 :     #
386 :     # A pending function call:
387 :     # Keep working if the precedence of the operator is higher than a function call
388 :     # Otherwise apply the function to the operator and continue
389 :     #
390 :     # Anything else:
391 :     # Return (no more pending operations)
392 :     #
393 :     # If there was an error, stop processing
394 :     #
395 :     sub Precedence {
396 :     my $self = shift; my $precedence = shift;
397 :     my $context = $self->{context};
398 :     while ($self->state eq 'operand') {
399 :     my $prev = $self->prev;
400 :     for ($prev->{type}) {
401 :    
402 :     /operator/ and do {
403 :     my $prev_prec = $context->{operators}{$prev->{name}}{rprecedence};
404 :     $prev_prec = $prev->{precedence} unless $prev_prec;
405 :     return if ($precedence > $prev_prec);
406 :     if ($self->top(-2)->{type} eq 'operand' || $prev->{reverse}) {
407 :     return if ($precedence == $prev_prec &&
408 :     $context->{operators}{$prev->{name}}{associativity} eq 'right');
409 :     if ($self->top(-2)->{type} eq 'fn') {
410 :     my $top = $self->pop; my $op = $self->pop; my $fun = $self->pop;
411 :     if (Parser::Function::checkInverse($self,$fun,$op,$top)) {
412 :     $fun->{name} = $context->{functions}{$fun->{name}}{inverse};
413 :     $self->push($fun);
414 :     } else {$self->push($top,$op,$fun)}
415 :     } else {
416 :     my $rop = $self->pop; my $op = $self->pop; my $lop = $self->pop;
417 :     if ($op->{reverse}) {my $tmp = $rop; $rop = $lop; $lop = $tmp}
418 : dpvc 2678 $self->pushOperand($context->{parser}{BOP}->new($self,$op->{name},
419 : sh002i 2558 $lop->{value},$rop->{value},$op->{ref}),$op->{reverse});
420 :     }
421 :     } else {
422 :     my $rop = $self->pop; my $op = $self->pop;
423 : dpvc 2678 $self->pushOperand($context->{parser}{UOP}->new
424 : sh002i 2558 ($self,$op->{name},$rop->{value},$op->{ref}),$op->{reverse});
425 :     }
426 :     last;
427 :     };
428 :    
429 :     /fn/ and do {
430 :     return if ($precedence > $context->{operators}{fn}{precedence});
431 :     $self->CloseFn();
432 :     last;
433 :     };
434 :    
435 :     return;
436 :    
437 :     }
438 :     return if ($self->{error});
439 :     }
440 :     }
441 :    
442 :     ##################################################
443 :     #
444 :     # Apply a function to its parameters
445 :     #
446 :     # If the operand is a list and the parens are those for function calls
447 :     # Use the list items as the parameters, otherwise use the top item
448 :     # Pop the function object, and push the result of the function call
449 :     #
450 :     sub CloseFn {
451 :     my $self = shift; my $context = $self->{context};
452 :     my $top = $self->pop->{value}; my $fn = $self->pop;
453 :     my $constant = $top->{isConstant};
454 :     if ($context->{parens}{$top->{open}}{function} &&
455 :     $context->{parens}{$top->{open}}{close} eq $top->{close} &&
456 :     !$context->{functions}{$fn->{name}}{vectorInput})
457 :     {$top = $top->coords} else {$top = [$top]}
458 : dpvc 2678 $self->pushOperand($context->{parser}{Function}->new
459 : sh002i 2558 ($self,$fn->{name},$top,$constant,$fn->{ref}));
460 :     }
461 :    
462 :     ##################################################
463 :     #
464 :     # Handle a numeric token
465 :     #
466 :     # Add an implicit multiplication, if needed
467 : dpvc 2650 # Create the number object and check it
468 : sh002i 2558 # Save the number as an operand
469 :     #
470 :     sub Num {
471 :     my $self = shift;
472 :     $self->ImplicitMult() if $self->state eq 'operand';
473 : dpvc 2678 my $num = $self->{context}{parser}{Number}->new($self,shift,$self->{ref});
474 : dpvc 2650 my $check = $self->{context}->flag('NumberCheck');
475 :     &$check($num) if $check;
476 :     $self->pushOperand($num);
477 : sh002i 2558 }
478 :    
479 :     ##################################################
480 :     #
481 :     # Handle a constant token
482 :     #
483 :     # Add an implicit multiplication, if needed
484 :     # Save the number as an operand
485 :     #
486 :     sub Const {
487 : dpvc 2678 my $self = shift; my $ref = $self->{ref}; my $name = shift;
488 :     my $const = $self->{context}{constants}{$name};
489 :     my $parser = $self->{context}{parser};
490 : sh002i 2558 $self->ImplicitMult() if $self->state eq 'operand';
491 :     if (defined($self->{context}{variables}{$name})) {
492 : dpvc 2678 $self->pushOperand($parser->{Variable}->new($self,$name,$ref));
493 : sh002i 2558 } elsif ($const->{keepName}) {
494 : dpvc 2678 $self->pushOperand($parser->{Constant}->new($self,$name,$ref));
495 : sh002i 2558 } else {
496 : dpvc 2678 $self->pushOperand($parser->{Value}->new($self,[$const->{value}],$ref));
497 : sh002i 2558 }
498 :     }
499 :    
500 :     ##################################################
501 :     #
502 :     # Handle a variable token
503 :     #
504 :     # Add an implicit multiplication, if needed
505 :     # Save the variable as an operand
506 :     #
507 :     sub Var {
508 :     my $self = shift;
509 :     $self->ImplicitMult() if $self->state eq 'operand';
510 : dpvc 2678 $self->pushOperand($self->{context}{parser}{Variable}->new($self,shift,$self->{ref}));
511 : sh002i 2558 }
512 :    
513 :     ##################################################
514 :     #
515 :     # Handle a function token
516 :     #
517 :     # Add an implicit multiplication, if needed
518 :     # Save the function object on the stack
519 :     #
520 :     sub Fn {
521 :     my $self = shift;
522 :     $self->ImplicitMult() if $self->state eq 'operand';
523 :     $self->push({type => 'fn', name => shift, ref => $self->{ref}});
524 :     }
525 :    
526 :     ##################################################
527 :     #
528 :     # Handle a string constant
529 :     #
530 :     # Add an implicit multiplication, if needed (will report an error)
531 :     # Save the string object on the stack
532 :     #
533 :     sub Str {
534 :     my $self = shift;
535 :     $self->ImplicitMult() if $self->state eq 'operand';
536 : dpvc 2678 $self->pushOperand($self->{context}{parser}{String}->new($self,shift,$self->{ref}));
537 : sh002i 2558 }
538 :    
539 :     ##################################################
540 :     ##################################################
541 :     #
542 :     # Evaluate the equation using the given values
543 :     #
544 :     sub eval {
545 :     my $self = shift;
546 :     $self->setValues(@_);
547 :     foreach my $x (keys %{$self->{values}}) {
548 :     $self->Error("The value of '$x' can't be a formula")
549 :     if Value::isFormula($self->{values}{$x});
550 :     }
551 :     $self->{tree}->eval;
552 :     }
553 :    
554 :     ##################################################
555 :     #
556 :     # Removes redundent items (like x+-y, 0+x and 1*x, etc)
557 :     # (substituting the given values).
558 :     #
559 :     sub reduce {
560 :     my $self = shift;
561 :     $self = $self->copy($self);
562 :     $self->setValues(@_);
563 :     $self->{tree} = $self->{tree}->reduce;
564 :     $self->{variables} = $self->{tree}->getVariables;
565 :     return $self;
566 :     }
567 :    
568 :     ##################################################
569 :     #
570 :     # Substitute values for one or more variables
571 :     #
572 :     sub substitute {
573 :     my $self = shift;
574 :     $self = $self->copy($self);
575 :     $self->setValues(@_);
576 :     foreach my $x (keys %{$self->{values}}) {delete $self->{variables}{$x}}
577 :     $self->{tree} = $self->{tree}->substitute;
578 :     return $self;
579 :     }
580 :    
581 :     ##################################################
582 :     #
583 :     # Produces a printable string (substituting the given values).
584 :     #
585 :     sub string {
586 :     my $self = shift;
587 :     $self->setValues(@_);
588 :     $self->{tree}->string;
589 :     }
590 :    
591 :     ##################################################
592 :     #
593 :     # Produces a TeX string (substituting the given values).
594 :     #
595 :     sub TeX {
596 :     my $self = shift;
597 :     $self->setValues(@_);
598 :     $self->{tree}->TeX;
599 :     }
600 :    
601 :     ##################################################
602 :     #
603 :     # Produces a perl eval string (substituting the given values).
604 :     #
605 :     sub perl {
606 :     my $self = shift;
607 :     $self->setValues(@_);
608 :     $self->{tree}->perl;
609 :     }
610 :    
611 :     ##################################################
612 :     #
613 :     # Produce a perl function
614 :     #
615 :     # (Parameters specify an optional name and an array reference of
616 :     # optional variables. If the name is not included, an anonymous
617 :     # code reference is returned. If the variables are not included,
618 :     # then the variables from the formula are used in sorted order.)
619 :     #
620 :     sub perlFunction {
621 :     my $self = shift; my $name = shift; my $vars = shift;
622 :     $vars = [sort(keys %{$self->{variables}})] unless $vars;
623 :     my $n = scalar(@{$vars}); my $vnames = '';
624 :     if ($n > 0) {
625 :     my @v = (); foreach my $x (@{$vars}) {push(@v,'$'.$x)}
626 :     $vnames = "my (".join(',',@v).") = \@_;";
627 :     }
628 :     my $fn = eval
629 :     "package main;
630 :     sub $name {
631 :     die \"Wrong number of arguments".($name?" to '$name'":'')."\" if scalar(\@_) != $n;
632 :     $vnames
633 :     return ".$self->perl.";
634 :     }";
635 :     $self->Error($@) if $@;
636 :     return $fn;
637 :     }
638 :    
639 :    
640 :     ##################################################
641 :     #
642 :     # Sets the values of variables for evaluation purposes
643 :     #
644 :     sub setValues {
645 :     my $self = shift; my ($value,$type);
646 :     my $variables = $self->{context}{variables};
647 :     $self->{values} = {@_};
648 :     foreach my $x (keys %{$self->{values}}) {
649 :     $self->Error("Undeclared variable '$x'") unless defined $variables->{$x};
650 : dpvc 2605 $value = Value::makeValue($self->{values}{$x});
651 : dpvc 2628 $value = Value::Formula->new($value) unless Value::isValue($value);
652 :     ($value,$type) = Value::getValueType($self,$value);
653 : sh002i 2558 $self->Error("Variable '$x' should be of type $variables->{$x}{type}{name}")
654 : dpvc 2605 unless Parser::Item::typeMatch($type,$variables->{$x}{type});
655 : sh002i 2558 $self->{values}{$x} = $value;
656 :     }
657 :     }
658 :    
659 : dpvc 2576
660 : dpvc 2579 ##################################################
661 :     ##################################################
662 :     #
663 :     # Produce a vector in ijk form
664 :     #
665 :     sub ijk {
666 :     my $self = shift;
667 :     $self->{tree}->ijk;
668 :     }
669 :    
670 : sh002i 2558 #########################################################################
671 :     #########################################################################
672 :     #
673 :     # Load the sub-classes and Value.pm
674 :     #
675 :    
676 :     use Parser::Item;
677 :     use Value;
678 :     use Parser::Context;
679 : dpvc 2579 use Parser::Context::Default;
680 : dpvc 2664 use Parser::Differentiation;
681 : dpvc 2579
682 : dpvc 2576 ###########################################################################
683 : dpvc 2592
684 :     use vars qw($installed);
685 :     $Parser::installed = 1;
686 :    
687 : dpvc 2576 ###########################################################################
688 : dpvc 2592 ###########################################################################
689 : dpvc 2576 #
690 :     # To Do:
691 :     #
692 :     # handle sqrt(-1) and log of negatives (make complexes)
693 :     # do division by zero and log of zero checks in compound functions
694 :     # add context flags for various reduction checks
695 :     # make context flag for reduction of constants
696 :     # make reduce have reduce patterns as parameters
697 :     # more reduce patterns
698 :     # make operator strings customizable (reduce, and other places they are used)
699 :     # add parens alternately as () and []?
700 :     #
701 : sh002i 2558 #########################################################################
702 :    
703 :     1;
704 :    

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