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37 * Implements functions in parsetree.h.
39 * \author Teemu Murtola <teemu.murtola@gmail.com>
40 * \ingroup module_selection
43 * \page page_module_selection_parser Selection parsing
45 * The selection parser is implemented in the following files:
47 * Tokenizer implemented using Flex, splits the input into tokens
48 * (scanner.c and scanner_flex.h are generated from this file).
49 * - scanner.h, scanner_internal.h, scanner_internal.cpp:
50 * Helper functions for scanner.l and for interfacing between
51 * scanner.l and parser.y. Functions in scanner_internal.h are only
52 * used from scanner.l, while scanner.h is used from the parser.
53 * - symrec.h, symrec.cpp:
54 * Functions used by the tokenizer to handle the symbol table, i.e.,
55 * the recognized keywords. Some basic keywords are hardcoded into
56 * scanner.l, but all method and variable references go through the
57 * symbol table, as do position evaluation keywords.
59 * Semantic rules for parsing the grammar
60 * (parser.cpp and parser.h are generated from this file by Bison).
61 * - parsetree.h, parsetree.cpp:
62 * Functions called from actions in parser.y to construct the
63 * evaluation elements corresponding to different grammar elements.
65 * Defines a function that processes the parameters of selection
66 * methods and initializes the children of the method element.
67 * - selectioncollection.h, selectioncollection.cpp:
68 * These files define the high-level public interface to the parser
69 * through SelectionCollection::parseInteractive(),
70 * SelectionCollection::parseFromStdin(),
71 * SelectionCollection::parseFromFile(), and
72 * SelectionCollection::parseFromString().
74 * The basic control flow in the parser is as follows: when a parser function
75 * in SelectionCollection gets called, it performs some
76 * initialization, and then calls the _gmx_sel_yyparse() function generated
77 * by Bison. This function then calls _gmx_sel_yylex() to repeatedly read
78 * tokens from the input (more complex tasks related to token recognition
79 * and bookkeeping are done by functions in scanner_internal.cpp) and uses the
80 * grammar rules to decide what to do with them. Whenever a grammar rule
81 * matches, a corresponding function in parsetree.cpp is called to construct
82 * either a temporary representation for the object or a
83 * gmx::SelectionTreeElement object
84 * (some simple rules are handled internally in parser.y).
85 * When a complete selection has been parsed, the functions in parsetree.cpp
86 * also take care of updating the ::gmx_ana_selcollection_t structure
89 * The rest of this page describes the resulting gmx::SelectionTreeElement
91 * Before the selections can be evaluated, this tree needs to be passed to
92 * the selection compiler, which is described on a separate page:
93 * \ref page_module_selection_compiler
96 * \section selparser_tree Element tree constructed by the parser
98 * The parser initializes the following fields in all selection elements:
99 * gmx::SelectionTreeElement::name, gmx::SelectionTreeElement::type,
100 * gmx::SelectionTreeElement::v\c .type,
101 * gmx::SelectionTreeElement::flags, gmx::SelectionTreeElement::child, and
102 * gmx::SelectionTreeElement::next.
103 * Some other fields are also initialized for particular element types as
105 * Fields that are not initialized are set to zero, NULL, or other similar
109 * \subsection selparser_tree_root Root elements
111 * The parser creates a \ref SEL_ROOT selection element for each variable
112 * assignment and each selection. However, there are two exceptions that do
113 * not result in a \ref SEL_ROOT element (in these cases, only the symbol
114 * table is modified):
115 * - Variable assignments that assign a variable to another variable.
116 * - Variable assignments that assign a non-group constant.
118 * The \ref SEL_ROOT elements are linked together in a chain in the same order
121 * The children of the \ref SEL_ROOT elements can be used to distinguish
122 * the two types of root elements from each other:
123 * - For variable assignments, the first and only child is always
124 * a \ref SEL_SUBEXPR element.
125 * - For selections, the first child is a \ref SEL_EXPRESSION or a
126 * \ref SEL_MODIFIER element that evaluates the final positions (if the
127 * selection defines a constant position, the child is a \ref SEL_CONST).
128 * The rest of the children are \ref SEL_MODIFIER elements with
129 * \ref NO_VALUE, in the order given by the user.
131 * The name of the selection/variable is stored in
132 * gmx::SelectionTreeElement::cgrp\c .name.
133 * It is set to either the name provided by the user or the selection string
134 * for selections not explicitly named by the user.
135 * \ref SEL_ROOT or \ref SEL_SUBEXPR elements do not appear anywhere else.
138 * \subsection selparser_tree_const Constant elements
140 * \ref SEL_CONST elements are created for every constant that is required
141 * for later evaluation.
142 * Currently, \ref SEL_CONST elements can be present for
143 * - selections that consist of a constant position,
144 * - \ref GROUP_VALUE method parameters if provided using external index
147 * For group-valued elements, the value is stored in
148 * gmx::SelectionTreeElement::cgrp; other types of values are stored in
149 * gmx::SelectionTreeElement::v.
150 * Constants that appear as parameters for selection methods are not present
151 * in the selection tree unless they have \ref GROUP_VALUE.
152 * \ref SEL_CONST elements have no children.
155 * \subsection selparser_tree_method Method evaluation elements
157 * \ref SEL_EXPRESSION and \ref SEL_MODIFIER elements are treated very
158 * similarly. The \c gmx_ana_selmethod_t structure corresponding to the
159 * evaluation method is in gmx::SelectionTreeElement::method, and the method
160 * data in gmx::SelectionTreeElement::mdata has been allocated using
162 * If a non-standard reference position type was set,
163 * gmx::SelectionTreeElement::pc has also been created, but only the type has
165 * All children of these elements are of the type \ref SEL_SUBEXPRREF, and
166 * each describes a selection that needs to be evaluated to obtain a value
167 * for one parameter of the method.
168 * No children are present for parameters that were given a constant
169 * non-\ref GROUP_VALUE value.
170 * The children are sorted in the order in which the parameters appear in the
171 * \ref gmx_ana_selmethod_t structure.
173 * In addition to actual selection keywords, \ref SEL_EXPRESSION elements
174 * are used internally to implement numerical comparisons (e.g., "x < 5")
175 * and keyword matching (e.g., "resnr 1 to 3" or "name CA").
178 * \subsection selparser_tree_subexpr Subexpression elements
180 * \ref SEL_SUBEXPR elements only appear for variables, as described above.
181 * gmx::SelectionTreeElement::name points to the name of the variable (from the
182 * \ref SEL_ROOT element).
183 * The element always has exactly one child, which represents the value of
186 * \ref SEL_SUBEXPRREF elements are used for two purposes:
187 * - Variable references that need to be evaluated (i.e., there is a
188 * \ref SEL_SUBEXPR element for the variable) are represented using
189 * \ref SEL_SUBEXPRREF elements.
190 * In this case, gmx::SelectionTreeElement::param is NULL, and the first and
191 * only child of the element is the \ref SEL_SUBEXPR element of the
193 * Such references can appear anywhere where the variable value
194 * (the child of the \ref SEL_SUBEXPR element) would be valid.
195 * - Children of \ref SEL_EXPRESSION and \ref SEL_MODIFIER elements are
196 * always of this type. For these elements, gmx::SelectionTreeElement::param
197 * is initialized to point to the parameter that receives the value from
199 * Each such element has exactly one child, which can be of any type;
200 * the \ref SEL_SUBEXPR element of a variable is used if the value comes
201 * from a variable, otherwise the child type is not \ref SEL_SUBEXPR.
204 * \subsection selparser_tree_bool Boolean elements
206 * One \ref SEL_BOOLEAN element is created for each boolean keyword in the
207 * input, and the tree structure represents the evaluation order.
208 * The gmx::SelectionTreeElement::boolt type gives the type of the operation.
209 * Each element has exactly two children (one for \ref BOOL_NOT elements),
210 * which are in the order given in the input.
211 * The children always have \ref GROUP_VALUE, but different element types
215 * \subsection selparser_tree_arith Arithmetic elements
217 * One \ref SEL_ARITHMETIC element is created for each arithmetic operation in
218 * the input, and the tree structure represents the evaluation order.
219 * The gmx::SelectionTreeElement::optype type gives the name of the operation.
220 * Each element has exactly two children (one for unary negation elements),
221 * which are in the order given in the input.
225 #include "parsetree.h"
233 #include "gromacs/selection/selection.h"
234 #include "gromacs/utility/cstringutil.h"
235 #include "gromacs/utility/exceptions.h"
236 #include "gromacs/utility/smalloc.h"
237 #include "gromacs/utility/stringutil.h"
238 #include "gromacs/utility/textwriter.h"
240 #include "keywords.h"
243 #include "selectioncollection_impl.h"
245 #include "selmethod.h"
248 using gmx::SelectionLocation;
249 using gmx::SelectionParserParameter;
250 using gmx::SelectionParserParameterList;
251 using gmx::SelectionParserParameterListPointer;
252 using gmx::SelectionParserValue;
253 using gmx::SelectionParserValueList;
254 using gmx::SelectionParserValueListPointer;
255 using gmx::SelectionTreeElement;
256 using gmx::SelectionTreeElementPointer;
262 * Formats context string for errors.
264 * The returned string is used as the context for errors reported during
267 std::string formatCurrentErrorContext(yyscan_t scanner)
269 return gmx::formatString("While parsing '%s'", _gmx_sel_lexer_get_current_text(scanner).c_str());
274 bool _gmx_selparser_handle_exception(yyscan_t scanner, std::exception* ex)
278 bool canContinue = false;
279 gmx::GromacsException* gromacsException = dynamic_cast<gmx::GromacsException*>(ex);
280 if (gromacsException != nullptr)
282 gromacsException->prependContext(formatCurrentErrorContext(scanner));
283 canContinue = (dynamic_cast<gmx::UserInputError*>(ex) != nullptr);
285 _gmx_sel_lexer_set_exception(scanner, std::current_exception());
288 catch (const std::exception&)
290 _gmx_sel_lexer_set_exception(scanner, std::current_exception());
295 bool _gmx_selparser_handle_error(yyscan_t scanner)
297 std::string context(gmx::formatString("Invalid selection '%s'", _gmx_sel_lexer_pselstr(scanner)));
298 // The only way to prepend context to the exception is to rethrow it.
301 _gmx_sel_lexer_rethrow_exception_if_occurred(scanner);
303 catch (gmx::UserInputError& ex)
305 ex.prependContext(context);
306 gmx::TextWriter* statusWriter = _gmx_sel_lexer_get_status_writer(scanner);
307 if (statusWriter != nullptr)
309 gmx::formatExceptionMessageToWriter(statusWriter, ex);
314 catch (gmx::GromacsException& ex)
316 ex.prependContext(context);
319 GMX_RELEASE_ASSERT(false, "All parsing errors should result in a captured exception");
320 return false; // Some compilers will not believe that the above never returns.
326 /********************************************************************
327 * SelectionParserValue
330 SelectionParserValue::SelectionParserValue(e_selvalue_t type, const SelectionLocation& location) :
334 memset(&u, 0, sizeof(u));
337 SelectionParserValue::SelectionParserValue(const SelectionTreeElementPointer& expr) :
340 location_(expr->location())
342 memset(&u, 0, sizeof(u));
345 /********************************************************************
346 * SelectionParserParameter
349 SelectionParserParameter::SelectionParserParameter(const char* name,
350 SelectionParserValueListPointer values,
351 const SelectionLocation& location) :
352 name_(name != nullptr ? name : ""),
354 values_(values ? std::move(values) : std::make_unique<SelectionParserValueList>())
361 * \param[in,out] sel Root of the selection element tree to initialize.
363 * Propagates the \ref SEL_DYNAMIC flag from the children of \p sel to \p sel
364 * (if any child of \p sel is dynamic, \p sel is also marked as such).
365 * The \ref SEL_DYNAMIC flag is also set for \ref SEL_EXPRESSION elements with
367 * Also, sets one of the \ref SEL_SINGLEVAL, \ref SEL_ATOMVAL, or
368 * \ref SEL_VARNUMVAL flags, either based on the children or on the type of
369 * the selection method.
370 * If the types of the children conflict, an error is returned.
372 * The flags of the children of \p sel are also updated if not done earlier.
373 * The flags are initialized only once for any element; if \ref SEL_FLAGSSET
374 * is set for an element, the function returns immediately, and the recursive
375 * operation does not descend beyond such elements.
377 void _gmx_selelem_update_flags(const gmx::SelectionTreeElementPointer& sel)
379 bool bUseChildType = false;
380 bool bOnlySingleChildren;
382 /* Return if the flags have already been set */
383 if (sel->flags & SEL_FLAGSSET)
387 /* Set the flags based on the current element type */
392 sel->flags |= SEL_SINGLEVAL;
393 bUseChildType = false;
397 if (sel->u.expr.method->flags & SMETH_DYNAMIC)
399 sel->flags |= SEL_DYNAMIC;
401 if (sel->u.expr.method->flags & SMETH_SINGLEVAL)
403 sel->flags |= SEL_SINGLEVAL;
405 else if (sel->u.expr.method->flags & SMETH_VARNUMVAL)
407 sel->flags |= SEL_VARNUMVAL;
411 sel->flags |= SEL_ATOMVAL;
413 bUseChildType = false;
417 sel->flags |= SEL_ATOMVAL;
418 bUseChildType = false;
422 if (sel->v.type != NO_VALUE)
424 sel->flags |= SEL_VARNUMVAL;
426 bUseChildType = false;
429 case SEL_ROOT: bUseChildType = false; break;
433 case SEL_SUBEXPRREF: bUseChildType = true; break;
435 /* Loop through children to propagate their flags upwards */
436 bOnlySingleChildren = true;
437 SelectionTreeElementPointer child = sel->child;
440 /* Update the child */
441 _gmx_selelem_update_flags(child);
442 /* Propagate the dynamic and unsorted flags */
443 sel->flags |= (child->flags & (SEL_DYNAMIC | SEL_UNSORTED));
444 /* Propagate the type flag if necessary and check for problems */
447 if ((sel->flags & SEL_VALTYPEMASK) && !(sel->flags & child->flags & SEL_VALTYPEMASK))
449 // TODO: Recollect when this is triggered, and whether the type
451 GMX_THROW(gmx::InvalidInputError("Invalid combination of selection expressions"));
453 sel->flags |= (child->flags & SEL_VALTYPEMASK);
455 if (!(child->flags & SEL_SINGLEVAL))
457 bOnlySingleChildren = false;
462 /* For arithmetic expressions consisting only of single values,
463 * the result is also a single value. */
464 if (sel->type == SEL_ARITHMETIC && bOnlySingleChildren)
466 sel->flags = (sel->flags & ~SEL_VALTYPEMASK) | SEL_SINGLEVAL;
468 /* For root elements, the type should be propagated here, after the
469 * children have been updated. */
470 if (sel->type == SEL_ROOT)
472 GMX_ASSERT(sel->child, "Root elements should always have a child");
473 sel->flags |= (sel->child->flags & SEL_VALTYPEMASK);
475 /* Mark that the flags are set */
476 sel->flags |= SEL_FLAGSSET;
480 * \param[in,out] sel Selection element to initialize.
481 * \param[in] scanner Scanner data structure.
483 * A deep copy of the parameters is made to allow several
484 * expressions with the same method to coexist peacefully.
485 * Calls sel_datafunc() if one is specified for the method.
487 void _gmx_selelem_init_method_params(const gmx::SelectionTreeElementPointer& sel, yyscan_t scanner)
490 gmx_ana_selparam_t* orgparam;
491 gmx_ana_selparam_t* param;
495 nparams = sel->u.expr.method->nparams;
496 orgparam = sel->u.expr.method->param;
497 snew(param, nparams);
498 memcpy(param, orgparam, nparams * sizeof(gmx_ana_selparam_t));
499 for (i = 0; i < nparams; ++i)
501 param[i].flags &= ~SPAR_SET;
502 _gmx_selvalue_setstore(¶m[i].val, nullptr);
503 if (param[i].flags & SPAR_VARNUM)
505 param[i].val.nr = -1;
507 /* Duplicate the enum value array if it is given statically */
508 if ((param[i].flags & SPAR_ENUMVAL) && orgparam[i].val.u.ptr != nullptr)
512 /* Count the values */
514 while (orgparam[i].val.u.s[n] != nullptr)
518 _gmx_selvalue_reserve(¶m[i].val, n + 1);
519 memcpy(param[i].val.u.s, orgparam[i].val.u.s, (n + 1) * sizeof(param[i].val.u.s[0]));
523 if (sel->u.expr.method->init_data)
525 mdata = sel->u.expr.method->init_data(nparams, param);
527 if (sel->u.expr.method->set_poscoll)
529 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
531 sel->u.expr.method->set_poscoll(&sc->pcc, mdata);
533 /* Store the values */
534 sel->u.expr.method->param = param;
535 sel->u.expr.mdata = mdata;
539 * \param[in,out] sel Selection element to initialize.
540 * \param[in] method Selection method to set.
541 * \param[in] scanner Scanner data structure.
543 * Makes a copy of \p method and stores it in \p sel->u.expr.method,
544 * and calls _gmx_selelem_init_method_params();
546 void _gmx_selelem_set_method(const gmx::SelectionTreeElementPointer& sel,
547 gmx_ana_selmethod_t* method,
550 _gmx_selelem_set_vtype(sel, method->type);
551 sel->setName(method->name);
552 snew(sel->u.expr.method, 1);
553 memcpy(sel->u.expr.method, method, sizeof(gmx_ana_selmethod_t));
554 _gmx_selelem_init_method_params(sel, scanner);
558 * Initializes the reference position calculation for a \ref SEL_EXPRESSION
561 * \param[in,out] pcc Position calculation collection to use.
562 * \param[in,out] sel Selection element to initialize.
563 * \param[in] rpost Reference position type to use (NULL = default).
565 static void set_refpos_type(gmx::PositionCalculationCollection* pcc,
566 const SelectionTreeElementPointer& sel,
574 if (sel->u.expr.method->pupdate)
576 /* By default, use whole residues/molecules. */
577 sel->u.expr.pc = pcc->createCalculationFromEnum(rpost, POS_COMPLWHOLE);
581 std::string message = gmx::formatString(
582 "Position modifiers ('%s') is not applicable for '%s'", rpost, sel->u.expr.method->name);
583 GMX_THROW(gmx::InvalidInputError(message));
587 gmx::SelectionTreeElementPointer _gmx_sel_init_arithmetic(const gmx::SelectionTreeElementPointer& left,
588 const gmx::SelectionTreeElementPointer& right,
592 SelectionTreeElementPointer sel(
593 new SelectionTreeElement(SEL_ARITHMETIC, _gmx_sel_lexer_get_current_location(scanner)));
594 sel->v.type = REAL_VALUE;
597 case '+': sel->u.arith.type = ARITH_PLUS; break;
598 case '-': sel->u.arith.type = (right ? ARITH_MINUS : ARITH_NEG); break;
599 case '*': sel->u.arith.type = ARITH_MULT; break;
600 case '/': sel->u.arith.type = ARITH_DIV; break;
601 case '^': sel->u.arith.type = ARITH_EXP; break;
603 char buf[2]{ op, 0 };
605 sel->u.arith.opstr = gmx_strdup(buf);
607 sel->child->next = right;
612 * \param[in] left Selection element for the left hand side.
613 * \param[in] right Selection element for the right hand side.
614 * \param[in] cmpop String representation of the comparison operator.
615 * \param[in] scanner Scanner data structure.
616 * \returns The created selection element.
618 * This function handles the creation of a gmx::SelectionTreeElement object for
619 * comparison expressions.
621 SelectionTreeElementPointer _gmx_sel_init_comparison(const gmx::SelectionTreeElementPointer& left,
622 const gmx::SelectionTreeElementPointer& right,
626 SelectionTreeElementPointer sel(
627 new SelectionTreeElement(SEL_EXPRESSION, _gmx_sel_lexer_get_current_location(scanner)));
628 _gmx_selelem_set_method(sel, &sm_compare, scanner);
630 SelectionParserParameterList params;
632 // Create the parameter for the left expression.
633 name = left->v.type == INT_VALUE ? "int1" : "real1";
634 params.push_back(SelectionParserParameter::createFromExpression(name, left));
635 // Create the parameter for the right expression.
636 name = right->v.type == INT_VALUE ? "int2" : "real2";
637 params.push_back(SelectionParserParameter::createFromExpression(name, right));
638 // Create the parameter for the operator.
639 // TODO: Consider whether a proper location is needed.
640 SelectionLocation location(SelectionLocation::createEmpty());
641 params.push_back(SelectionParserParameter::create(
642 "op", SelectionParserValue::createString(cmpop, location), location));
643 _gmx_sel_parse_params(params, sel->u.expr.method->nparams, sel->u.expr.method->param, sel, scanner);
649 * Implementation method for keyword expression creation.
651 * \param[in] method Method to use.
652 * \param[in] matchType String matching type (only used if \p method is
653 * a string keyword and \p args is not empty.
654 * \param[in] args Pointer to the first argument.
655 * \param[in] rpost Reference position type to use (NULL = default).
656 * \param[in] scanner Scanner data structure.
657 * \returns The created selection element.
659 * This function handles the creation of a gmx::SelectionTreeElement object for
660 * selection methods that do not take parameters.
662 static SelectionTreeElementPointer init_keyword_internal(gmx_ana_selmethod_t* method,
663 gmx::SelectionStringMatchType matchType,
664 SelectionParserValueListPointer args,
668 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
670 if (method->nparams > 0)
672 // TODO: Would assert be better?
673 GMX_THROW(gmx::InternalError("Keyword initialization called with non-keyword method"));
676 const SelectionLocation& location = _gmx_sel_lexer_get_current_location(scanner);
677 // TODO: If there are arguments, the location would be better as just the
678 // location of the keyword itself.
679 SelectionTreeElementPointer root(new SelectionTreeElement(SEL_EXPRESSION, location));
680 SelectionTreeElementPointer child = root;
681 _gmx_selelem_set_method(child, method, scanner);
683 /* Initialize the evaluation of keyword matching if values are provided */
686 gmx_ana_selmethod_t* kwmethod;
687 switch (method->type)
689 case INT_VALUE: kwmethod = &sm_keyword_int; break;
690 case REAL_VALUE: kwmethod = &sm_keyword_real; break;
691 case STR_VALUE: kwmethod = &sm_keyword_str; break;
692 default: GMX_THROW(gmx::InternalError("Unknown type for keyword selection"));
694 /* Initialize the selection element */
695 root = std::make_shared<SelectionTreeElement>(SEL_EXPRESSION, location);
696 _gmx_selelem_set_method(root, kwmethod, scanner);
697 if (method->type == STR_VALUE)
699 _gmx_selelem_set_kwstr_match_type(root, matchType);
701 SelectionParserParameterList params;
702 params.push_back(SelectionParserParameter::createFromExpression(nullptr, child));
703 params.push_back(SelectionParserParameter::create(nullptr, std::move(args), location));
704 _gmx_sel_parse_params(params, root->u.expr.method->nparams, root->u.expr.method->param,
707 set_refpos_type(&sc->pcc, child, rpost);
713 * \param[in] method Method to use.
714 * \param[in] args Pointer to the first argument.
715 * \param[in] rpost Reference position type to use (NULL = default).
716 * \param[in] scanner Scanner data structure.
717 * \returns The created selection element.
719 * This function handles the creation of a gmx::SelectionTreeElement object for
720 * selection methods that do not take parameters.
722 SelectionTreeElementPointer _gmx_sel_init_keyword(gmx_ana_selmethod_t* method,
723 gmx::SelectionParserValueListPointer args,
727 return init_keyword_internal(method, gmx::eStringMatchType_Auto, std::move(args), rpost, scanner);
731 * \param[in] method Method to use.
732 * \param[in] matchType String matching type.
733 * \param[in] args Pointer to the first argument.
734 * \param[in] rpost Reference position type to use (NULL = default).
735 * \param[in] scanner Scanner data structure.
736 * \returns The created selection element.
738 * This function handles the creation of a gmx::SelectionTreeElement object for
739 * keyword string matching.
741 SelectionTreeElementPointer _gmx_sel_init_keyword_strmatch(gmx_ana_selmethod_t* method,
742 gmx::SelectionStringMatchType matchType,
743 gmx::SelectionParserValueListPointer args,
747 GMX_RELEASE_ASSERT(method->type == STR_VALUE,
748 "String keyword method called for a non-string-valued method");
749 GMX_RELEASE_ASSERT(args && !args->empty(),
750 "String keyword matching method called without any values");
751 return init_keyword_internal(method, matchType, std::move(args), rpost, scanner);
755 * \param[in] method Method to use for initialization.
756 * \param[in] group Selection in which the keyword should be evaluated.
757 * \param[in] rpost Reference position type to use (NULL = default).
758 * \param[in] scanner Scanner data structure.
759 * \returns The created selection element.
761 * This function handles the creation of a gmx::SelectionTreeElement object for
762 * expressions like "z of ...".
764 SelectionTreeElementPointer _gmx_sel_init_keyword_of(gmx_ana_selmethod_t* method,
765 const gmx::SelectionTreeElementPointer& group,
769 // TODO Provide an error if rpost is provided.
770 GMX_UNUSED_VALUE(rpost);
771 return _gmx_sel_init_keyword_evaluator(method, group, scanner);
775 * \param[in] method Method to use for initialization.
776 * \param[in] params Pointer to the first parameter.
777 * \param[in] rpost Reference position type to use (NULL = default).
778 * \param[in] scanner Scanner data structure.
779 * \returns The created selection element.
781 * This function handles the creation of a gmx::SelectionTreeElement object for
782 * selection methods that take parameters.
784 * Part of the behavior of the \c same selection keyword is hardcoded into
785 * this function (or rather, into _gmx_selelem_custom_init_same()) to allow the
786 * use of any keyword in \c "same KEYWORD as" without requiring special
787 * handling somewhere else (or sacrificing the simple syntax).
789 SelectionTreeElementPointer _gmx_sel_init_method(gmx_ana_selmethod_t* method,
790 gmx::SelectionParserParameterListPointer params,
794 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
796 _gmx_sel_finish_method(scanner);
797 /* The "same" keyword needs some custom massaging of the parameters. */
798 _gmx_selelem_custom_init_same(&method, params, scanner);
799 SelectionTreeElementPointer root(
800 new SelectionTreeElement(SEL_EXPRESSION, _gmx_sel_lexer_get_current_location(scanner)));
801 _gmx_selelem_set_method(root, method, scanner);
802 /* Process the parameters */
803 _gmx_sel_parse_params(*params, root->u.expr.method->nparams, root->u.expr.method->param, root, scanner);
804 set_refpos_type(&sc->pcc, root, rpost);
810 * \param[in] method Modifier to use for initialization.
811 * \param[in] params Pointer to the first parameter.
812 * \param[in] sel Selection element that the modifier should act on.
813 * \param[in] scanner Scanner data structure.
814 * \returns The created selection element.
816 * This function handles the creation of a gmx::SelectionTreeElement object for
817 * selection modifiers.
819 SelectionTreeElementPointer _gmx_sel_init_modifier(gmx_ana_selmethod_t* method,
820 gmx::SelectionParserParameterListPointer params,
821 const gmx::SelectionTreeElementPointer& sel,
824 _gmx_sel_finish_method(scanner);
825 SelectionTreeElementPointer modifier(
826 new SelectionTreeElement(SEL_MODIFIER, _gmx_sel_lexer_get_current_location(scanner)));
827 _gmx_selelem_set_method(modifier, method, scanner);
828 SelectionTreeElementPointer root;
829 if (method->type == NO_VALUE)
831 SelectionTreeElementPointer child = sel;
836 child->next = modifier;
841 params->push_front(SelectionParserParameter::createFromExpression(nullptr, sel));
844 /* Process the parameters */
845 _gmx_sel_parse_params(*params, modifier->u.expr.method->nparams, modifier->u.expr.method->param,
852 * \param[in] expr Input selection element for the position calculation.
853 * \param[in] type Reference position type or NULL for default.
854 * \param[in] scanner Scanner data structure.
855 * \returns The created selection element.
857 * This function handles the creation of a gmx::SelectionTreeElement object for
858 * evaluation of reference positions.
860 SelectionTreeElementPointer _gmx_sel_init_position(const gmx::SelectionTreeElementPointer& expr,
864 SelectionTreeElementPointer root(
865 new SelectionTreeElement(SEL_EXPRESSION, _gmx_sel_lexer_get_current_location(scanner)));
866 _gmx_selelem_set_method(root, &sm_keyword_pos, scanner);
867 _gmx_selelem_set_kwpos_type(root.get(), type);
868 /* Create the parameters for the parameter parser. */
869 SelectionParserParameterList params;
870 params.push_back(SelectionParserParameter::createFromExpression(nullptr, expr));
871 /* Parse the parameters. */
872 _gmx_sel_parse_params(params, root->u.expr.method->nparams, root->u.expr.method->param, root, scanner);
878 * \param[in] x,y,z Coordinates for the position.
879 * \param[in] scanner Scanner data structure.
880 * \returns The creates selection element.
882 SelectionTreeElementPointer _gmx_sel_init_const_position(real x, real y, real z, yyscan_t scanner)
886 SelectionTreeElementPointer sel(
887 new SelectionTreeElement(SEL_CONST, _gmx_sel_lexer_get_current_location(scanner)));
888 _gmx_selelem_set_vtype(sel, POS_VALUE);
889 _gmx_selvalue_reserve(&sel->v, 1);
890 gmx_ana_pos_init_const(sel->v.u.p, pos);
895 * \param[in] name Name of an index group to search for.
896 * \param[in] scanner Scanner data structure.
897 * \returns The created selection element.
899 * See gmx_ana_indexgrps_find() for information on how \p name is matched
900 * against the index groups.
902 SelectionTreeElementPointer _gmx_sel_init_group_by_name(const char* name, yyscan_t scanner)
905 SelectionTreeElementPointer sel(
906 new SelectionTreeElement(SEL_GROUPREF, _gmx_sel_lexer_get_current_location(scanner)));
907 _gmx_selelem_set_vtype(sel, GROUP_VALUE);
908 sel->setName(gmx::formatString("group \"%s\"", name));
909 sel->u.gref.name = gmx_strdup(name);
912 if (_gmx_sel_lexer_has_groups_set(scanner))
914 gmx_ana_indexgrps_t* grps = _gmx_sel_lexer_indexgrps(scanner);
915 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
916 sel->resolveIndexGroupReference(grps, sc->gall.isize);
923 * \param[in] id Zero-based index number of the group to extract.
924 * \param[in] scanner Scanner data structure.
925 * \returns The created selection element.
927 SelectionTreeElementPointer _gmx_sel_init_group_by_id(int id, yyscan_t scanner)
929 SelectionTreeElementPointer sel(
930 new SelectionTreeElement(SEL_GROUPREF, _gmx_sel_lexer_get_current_location(scanner)));
931 _gmx_selelem_set_vtype(sel, GROUP_VALUE);
932 sel->setName(gmx::formatString("group %d", id));
933 sel->u.gref.name = nullptr;
936 if (_gmx_sel_lexer_has_groups_set(scanner))
938 gmx_ana_indexgrps_t* grps = _gmx_sel_lexer_indexgrps(scanner);
939 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
940 sel->resolveIndexGroupReference(grps, sc->gall.isize);
947 * \param[in,out] sel Value of the variable.
948 * \param scanner Scanner data structure.
949 * \returns The created selection element that references \p sel.
951 * The reference count of \p sel is updated, but no other modifications are
954 SelectionTreeElementPointer _gmx_sel_init_variable_ref(const gmx::SelectionTreeElementPointer& sel,
957 SelectionTreeElementPointer ref;
959 if (sel->v.type == POS_VALUE && sel->type == SEL_CONST)
965 ref = std::make_shared<SelectionTreeElement>(SEL_SUBEXPRREF,
966 _gmx_sel_lexer_get_current_location(scanner));
967 _gmx_selelem_set_vtype(ref, sel->v.type);
968 ref->setName(sel->name());
975 * \param[in] name Name for the selection
976 * (if NULL, a default name is constructed).
977 * \param[in] sel The selection element that evaluates the selection.
978 * \param scanner Scanner data structure.
979 * \returns The created root selection element.
981 * This function handles the creation of root (\ref SEL_ROOT)
982 * gmx::SelectionTreeElement objects for selections.
984 SelectionTreeElementPointer _gmx_sel_init_selection(const char* name,
985 const gmx::SelectionTreeElementPointer& sel,
988 if (sel->v.type != POS_VALUE)
990 /* FIXME: Better handling of this error */
991 GMX_THROW(gmx::InternalError("Each selection must evaluate to a position"));
994 SelectionTreeElementPointer root(
995 new SelectionTreeElement(SEL_ROOT, _gmx_sel_lexer_get_current_location(scanner)));
1001 /* Update the flags */
1002 _gmx_selelem_update_flags(root);
1003 gmx::ExceptionInitializer errors("Invalid index group reference(s)");
1004 root->checkUnsortedAtoms(true, &errors);
1005 if (errors.hasNestedExceptions())
1007 GMX_THROW(gmx::InconsistentInputError(errors));
1010 root->fillNameIfMissing(_gmx_sel_lexer_pselstr(scanner));
1012 /* Print out some information if the parser is interactive */
1013 gmx::TextWriter* statusWriter = _gmx_sel_lexer_get_status_writer(scanner);
1014 if (statusWriter != nullptr)
1016 const std::string message =
1017 gmx::formatString("Selection '%s' parsed", _gmx_sel_lexer_pselstr(scanner));
1018 statusWriter->writeLine(message);
1026 * \param[in] name Name of the variable.
1027 * \param[in] expr The selection element that evaluates the variable.
1028 * \param scanner Scanner data structure.
1029 * \returns The created root selection element.
1031 * This function handles the creation of root gmx::SelectionTreeElement objects
1032 * for variable assignments. A \ref SEL_ROOT element and a \ref SEL_SUBEXPR
1033 * element are both created.
1035 SelectionTreeElementPointer _gmx_sel_assign_variable(const char* name,
1036 const gmx::SelectionTreeElementPointer& expr,
1039 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
1040 const char* pselstr = _gmx_sel_lexer_pselstr(scanner);
1041 SelectionTreeElementPointer root;
1043 _gmx_selelem_update_flags(expr);
1044 /* Check if this is a constant non-group value */
1045 if (expr->type == SEL_CONST && expr->v.type != GROUP_VALUE)
1047 /* If so, just assign the constant value to the variable */
1048 sc->symtab->addVariable(name, expr);
1050 /* Check if we are assigning a variable to another variable */
1051 else if (expr->type == SEL_SUBEXPRREF)
1053 /* If so, make a simple alias */
1054 sc->symtab->addVariable(name, expr->child);
1058 SelectionLocation location(_gmx_sel_lexer_get_current_location(scanner));
1059 /* Create the root element */
1060 root = std::make_shared<SelectionTreeElement>(SEL_ROOT, location);
1061 root->setName(name);
1062 /* Create the subexpression element */
1063 root->child = std::make_shared<SelectionTreeElement>(SEL_SUBEXPR, location);
1064 root->child->setName(name);
1065 _gmx_selelem_set_vtype(root->child, expr->v.type);
1066 root->child->child = expr;
1068 _gmx_selelem_update_flags(root);
1069 gmx::ExceptionInitializer errors("Invalid index group reference(s)");
1070 root->checkUnsortedAtoms(true, &errors);
1071 if (errors.hasNestedExceptions())
1073 GMX_THROW(gmx::InconsistentInputError(errors));
1075 /* Add the variable to the symbol table */
1076 sc->symtab->addVariable(name, root->child);
1078 srenew(sc->varstrs, sc->nvars + 1);
1079 sc->varstrs[sc->nvars] = gmx_strdup(pselstr);
1081 gmx::TextWriter* statusWriter = _gmx_sel_lexer_get_status_writer(scanner);
1082 if (statusWriter != nullptr)
1084 const std::string message = gmx::formatString("Variable '%s' parsed", pselstr);
1085 statusWriter->writeLine(message);
1091 * \param sel Selection to append (can be NULL, in which
1092 * case nothing is done).
1093 * \param last Last selection, or NULL if not present or not known.
1094 * \param scanner Scanner data structure.
1095 * \returns The last selection after the append.
1097 * Appends \p sel after the last root element, and returns either \p sel
1098 * (if it was non-NULL) or the last element (if \p sel was NULL).
1100 SelectionTreeElementPointer _gmx_sel_append_selection(const gmx::SelectionTreeElementPointer& sel,
1101 gmx::SelectionTreeElementPointer last,
1104 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
1106 /* Append sel after last, or the last element of sc if last is NULL */
1127 /* Initialize a selection object if necessary */
1131 /* Add the new selection to the collection if it is not a variable. */
1132 if (sel->child->type != SEL_SUBEXPR)
1134 gmx::SelectionDataPointer selPtr(
1135 new gmx::internal::SelectionData(sel.get(), _gmx_sel_lexer_pselstr(scanner)));
1136 sc->sel.push_back(std::move(selPtr));
1139 /* Clear the selection string now that we've saved it */
1140 _gmx_sel_lexer_clear_pselstr(scanner);
1145 * \param[in] scanner Scanner data structure.
1146 * \returns true if the parser should finish, false if parsing should
1149 * This function is called always after _gmx_sel_append_selection() to
1150 * check whether a sufficient number of selections has already been provided.
1151 * This is used to terminate interactive parsers when the correct number of
1152 * selections has been provided.
1154 bool _gmx_sel_parser_should_finish(yyscan_t scanner)
1156 gmx_ana_selcollection_t* sc = _gmx_sel_lexer_selcollection(scanner);
1157 return gmx::ssize(sc->sel) == _gmx_sel_lexer_exp_selcount(scanner);