+++ /dev/null
-\section{\class{wxExpr}}\label{wxexpr}
-
-The {\bf wxExpr} class is the building brick of expressions similar to Prolog
-clauses, or objects. It can represent an expression of type long integer, float, string, word,
-or list, and lists can be nested.
-
-\wxheading{Derived from}
-
-None
-
-\wxheading{Include files}
-
-<wx/wxexpr.h>
-
-\wxheading{See also}
-
-\helpref{wxExpr overview}{exproverview}, \helpref{wxExprDatabase}{wxexprdatabase}
-
-\latexignore{\rtfignore{\wxheading{Members}}}
-
-\membersection{wxExpr::wxExpr}\label{wxexprconstr}
-
-\func{}{wxExpr}{\param{const wxString\&}{functor}}
-
-Construct a new clause with this form, supplying the functor name. A clause is an object
-that will appear in the data file, with a list of attribute/value pairs.
-
-\func{}{wxExpr}{\param{wxExprType}{ type}, \param{const wxString\&}{ wordOrString = ``"}}
-
-Construct a new empty list, or a word (will be output with no quotes), or a string, depending on the
-value of {\it type}.
-
-{\it type} can be {\bf wxExprList}, {\bf wxExprWord}, or {\bf wxExprString}. If {\it type} is wxExprList,
-the value of {\it wordOrString} will be ignored.
-
-\func{}{wxExpr}{\param{long}{ value}}
-
-Construct an integer expression.
-
-\func{}{wxExpr}{\param{float}{ value}}
-
-Construct a floating point expression.
-
-\func{}{wxExpr}{\param{wxList* }{value}}
-
-Construct a list expression. The list's nodes' data should
-themselves be {\bf wxExpr}s.
-
-wxExpr no longer uses the {\bf wxList} internally,
-so this constructor turns the list into its internal
-format (assuming a non-nested list) and then deletes the supplied
-list.
-
-\membersection{wxExpr::\destruct{wxExpr}}
-
-\func{}{\destruct{wxExpr}}{\void}
-
-Destructor.
-
-\membersection{wxExpr::AddAttributeValue}\label{wxexpraddattributevalue}
-
-Use these on clauses ONLY. Note that the functions for adding strings
-and words must be differentiated by function name which is why
-they are missing from this group (see \helpref{wxExpr::AddAttributeValueString}{wxexpraddattributevaluestring} and
-\rtfsp\helpref{wxExpr::AddAttributeValueWord}{wxexpraddattributevalueword}).
-
-\func{void}{AddAttributeValue}{\param{const wxString\&}{ attribute}, \param{float }{value}}
-
-Adds an attribute and floating point value pair to the clause.
-
-\func{void}{AddAttributeValue}{\param{const wxString\&}{ attribute}, \param{long }{value}}
-
-Adds an attribute and long integer value pair to the clause.
-
-\func{void}{AddAttributeValue}{\param{const wxString\&}{ attribute}, \param{wxList* }{value}}
-
-Adds an attribute and list value pair to the clause, converting the list into
-internal form and then deleting {\bf value}. Note that the list should not contain
-nested lists (except if in internal {\bf wxExpr} form.)
-
-\func{void}{AddAttributeValue}{\param{const wxString\&}{ attribute}, \param{wxExpr* }{value}}
-
-Adds an attribute and wxExpr value pair to the clause. Do not delete\rtfsp
-{\it value} once this function has been called.
-
-\membersection{wxExpr::AddAttributeValueString}\label{wxexpraddattributevaluestring}
-
-\func{void}{AddAttributeValueString}{\param{const wxString\&}{ attribute}, \param{const wxString\&}{ value}}
-
-Adds an attribute and string value pair to the clause.
-
-\membersection{wxExpr::AddAttributeValueStringList}\label{wxexpraddattributevaluestringlist}
-
-\func{void}{AddAttributeValueStringList}{\param{const wxString\&}{ attribute}, \param{wxList* }{value}}
-
-Adds an attribute and string list value pair to the clause.
-
-Note that the list passed to this function is a list of strings, NOT a list
-of {\bf wxExpr}s; it gets turned into a list of {\bf wxExpr}s
-automatically. This is a convenience function, since lists of strings
-are often manipulated in C++.
-
-\membersection{wxExpr::AddAttributeValueWord}\label{wxexpraddattributevalueword}
-
-\func{void}{AddAttributeValueWord}{\param{const wxString\&}{ attribute}, \param{const wxString\&}{ value}}
-
-Adds an attribute and word value pair to the clause.
-
-\membersection{wxExpr::Append}\label{wxexprappend}
-
-\func{void}{Append}{\param{wxExpr*}{ value}}
-
-Append the {\bf value} to the end of the list. `this' must be a list.
-
-\membersection{wxExpr::Arg}\label{wxexprarg}
-
-\constfunc{wxExpr* }{Arg}{\param{wxExprType}{ type}, \param{int}{ n}}
-
-Get nth arg of the given clause (starting from 1). NULL is returned if
-the expression is not a clause, or {\it n} is invalid, or the given type
-does not match the actual type. See also \helpref{wxExpr::Nth}{wxexprnth}.
-
-\membersection{wxExpr::Insert}\label{wxexprinsert}
-
-\func{void}{Insert}{\param{wxExpr* }{value}}
-
-Insert the {\bf value} at the start of the list. `this' must be a list.
-
-\membersection{wxExpr::GetAttributeValue}\label{wxexprgetattributevalue}
-
-These functions are the easiest way to retrieve attribute values, by
-passing a pointer to variable. If the attribute is present, the
-variable will be filled with the appropriate value. If not, the
-existing value is left alone. This style of retrieving attributes
-makes it easy to set variables to default values before calling these
-functions; no code is necessary to check whether the attribute is
-present or not.
-
-\constfunc{bool}{GetAttributeValue}{\param{const wxString\&}{ attribute}, \param{wxString\&}{ value}}
-
-Retrieve a string (or word) value.
-
-\constfunc{bool}{GetAttributeValue}{\param{const wxString\&}{ attribute}, \param{float\& }{value}}
-
-Retrieve a floating point value.
-
-\constfunc{bool}{GetAttributeValue}{\param{const wxString\&}{ attribute}, \param{int\& }{value}}
-
-Retrieve an integer value.
-
-\constfunc{bool}{GetAttributeValue}{\param{const wxString\&}{ attribute}, \param{long\& }{value}}
-
-Retrieve a long integer value.
-
-\constfunc{bool}{GetAttributeValue}{\param{const wxString\&}{ attribute}, \param{wxExpr**}{ value}}
-
-Retrieve a wxExpr pointer.
-
-\membersection{wxExpr::GetAttributeValueStringList}\label{wxexprgetattributestringlist}
-
-\constfunc{void}{GetAttributeValueStringList}{\param{const wxString\&}{attribute}, \param{wxList* }{value}}
-
-Use this on clauses ONLY. See above for comments on this style of
-attribute value retrieval. This function expects to receive a pointer to
-a new list (created by the calling application); it will append strings
-to the list if the attribute is present in the clause.
-
-\membersection{wxExpr::AttributeValue}\label{wxexprattributevalue}
-
-\constfunc{wxExpr*}{AttributeValue}{\param{const wxString\&}{ word}}
-
-Use this on clauses ONLY. Searches the clause for an attribute
-matching {\it word}, and returns the value associated with it.
-
-\membersection{wxExpr::Copy}\label{wxexprcopy}
-
-\constfunc{wxExpr*}{Copy}{\void}
-
-Recursively copies the expression, allocating new storage space.
-
-\membersection{wxExpr::DeleteAttributeValue}\label{wxexprdeletattributevalue}
-
-\func{void}{DeleteAttributeValue}{\param{const wxString\&}{ attribute}}
-
-Use this on clauses only. Deletes the attribute and its value (if any) from the
-clause.
-
-\membersection{wxExpr::Functor}\label{wxexprfunctor}
-
-\constfunc{wxString}{Functor}{\void}
-
-Use this on clauses only. Returns the clause's functor (object name).
-
-\membersection{wxExpr::GetClientData}\label{wxexprgetclientdata}
-
-\constfunc{wxObject*}{GetClientData}{\void}
-
-Retrieve arbitrary data stored with this clause. This can be useful when
-reading in data for storing a pointer to the C++ object, so when another
-clause makes a reference to this clause, its C++ object can be retrieved.
-See \helpref{wxExpr::SetClientData}{wxexprsetclientdata}.
-
-\membersection{wxExpr::GetFirst}\label{wxexprgetfirst}
-
-\constfunc{wxExpr*}{GetFirst}{\void}
-
-If this is a list expression (or clause), gets the first element in the list.
-
-See also \helpref{wxExpr::GetLast}{wxexprgetlast}, \helpref{wxExpr::GetNext}{wxexprgetnext}, \helpref{wxExpr::Nth}{wxexprnth}.
-
-\membersection{wxExpr::GetLast}\label{wxexprgetlast}
-
-\constfunc{wxExpr*}{GetLast}{\void}
-
-If this is a list expression (or clause), gets the last element in the list.
-
-See also \helpref{wxExpr::GetFirst}{wxexprgetfirst}, \helpref{wxExpr::GetNext}{wxexprgetnext}, \helpref{wxExpr::Nth}{wxexprnth}.
-
-\membersection{wxExpr::GetNext}\label{wxexprgetnext}
-
-\constfunc{wxExpr*}{GetNext}{\void}
-
-If this is a node in a list (any wxExpr may be a node in a list), gets the
-next element in the list.
-
-See also \helpref{wxExpr::GetFirst}{wxexprgetfirst}, \helpref{wxExpr::GetLast}{wxexprgetlast}, \helpref{wxExpr::Nth}{wxexprnth}.
-
-\membersection{wxExpr::IntegerValue}\label{wxexprintegervalue}
-
-\constfunc{long}{IntegerValue}{\void}
-
-Returns the integer value of the expression.
-
-\membersection{wxExpr::Nth}\label{wxexprnth}
-
-\constfunc{wxExpr*}{Nth}{\param{int}{ n}}
-
-Get nth arg of the given list expression (starting from 0). NULL is returned if
-the expression is not a list expression, or {\it n} is invalid. See also \helpref{wxExpr::Arg}{wxexprarg}.
-
-Normally, you would use attribute-value pairs to add and retrieve data
-from objects (clauses) in a data file. However, if the data gets complex,
-you may need to store attribute values as lists, and pick them apart
-yourself.
-
-\membersection{wxExpr::RealValue}\label{wxexprrealvalue}
-
-\constfunc{float}{RealValue}{\void}
-
-Returns the floating point value of the expression.
-
-\membersection{wxExpr::SetClientData}\label{wxexprsetclientdata}
-
-\func{void}{SetClientData}{\param{wxObject *}{data}}
-
-Associate arbitrary data with this clause. This can be useful when
-reading in data for storing a pointer to the C++ object, so when another
-clause makes a reference to this clause, its C++ object can be retrieved.
-See \helpref{wxExpr::GetClientData}{wxexprgetclientdata}.
-
-\membersection{wxExpr::StringValue}\label{wxexprstringvalue}
-
-\constfunc{wxString}{StringValue}{\void}
-
-Returns the string value of the expression.
-
-\membersection{wxExpr::Type}\label{wxexprtype}
-
-\constfunc{wxExprType}{Type}{\void}
-
-Returns the type of the expression. {\bf wxExprType} is defined as follows:
-
-\begin{verbatim}
-typedef enum {
- wxExprNull,
- wxExprInteger,
- wxExprReal,
- wxExprWord,
- wxExprString,
- wxExprList
-} wxExprType;
-\end{verbatim}
-
-\membersection{wxExpr::WordValue}\label{wxexprwordvalue}
-
-\constfunc{wxString}{WordValue}{\void}
-
-Returns the word value of the expression.
-
-\membersection{wxExpr::WriteClause}\label{wxexprwriteprologclause}
-
-\func{void}{WriteClause}{\param{FILE *}{ stream}}
-
-Writes the clause to the given stream in Prolog format. Not normally needed, since
-the whole {\bf wxExprDatabase} will usually be written at once. The format is:
-functor, open parenthesis, list of comma-separated expressions, close parenthesis,
-full stop.
-
-\membersection{wxExpr::WriteExpr}\label{wxexprwriteexpr}
-
-\func{void}{WriteExpr}{\param{FILE *}{ stream}}
-
-Writes the expression (not clause) to the given stream in Prolog
-format. Not normally needed, since the whole {\bf wxExprDatabase} will
-usually be written at once. Lists are written in square bracketed,
-comma-delimited format.
-
-\membersection{Functions and macros}
-
-Below are miscellaneous functions and macros associated with wxExpr objects.
-
-\func{bool}{wxExprIsFunctor}{\param{wxExpr *}{expr}, \param{const wxString\&}{ functor}}
-
-Checks that the functor of {\it expr} is {\it functor}.
-
-\func{void}{wxExprCleanUp}{\void}
-
-Cleans up the wxExpr system (YACC/LEX buffers) to avoid memory-checking warnings as the program exits.
-
-\begin{verbatim}
-#define wxMakeInteger(x) (new wxExpr((long)x))
-#define wxMakeReal(x) (new wxExpr((float)x))
-#define wxMakeString(x) (new wxExpr(PrologString, x))
-#define wxMakeWord(x) (new wxExpr(PrologWord, x))
-#define wxMake(x) (new wxExpr(x))
-\end{verbatim}
-
-Macros to help make wxExpr objects.
-
-\section{\class{wxExprDatabase}}\label{wxexprdatabase}
-
-The {\bf wxExprDatabase} class represents a database, or list,
-of Prolog-like expressions. Instances of this class are used for reading,
-writing and creating data files.
-
-\wxheading{Derived from}
-
-\helpref{wxList}{wxlist}\\
-\helpref{wxObject}{wxobject}
-
-\wxheading{See also}
-
-\helpref{wxExpr overview}{exproverview}, \helpref{wxExpr}{wxexpr}
-
-\latexignore{\rtfignore{\wxheading{Members}}}
-
-\membersection{wxExprDatabase::wxExprDatabase}\label{wxexprdatabaseconstr}
-
-\func{void}{wxExprDatabase}{\param{proioErrorHandler}{ handler = 0}}
-
-Construct a new, unhashed database, with an optional error handler. The
-error handler must be a function returning a bool and taking an integer and a string
-argument. When an error occurs when reading or writing a database, this function is
-called. The error is given as the first argument (currently one of WXEXPR\_ERROR\_GENERAL,
-WXEXPR\_ERROR\_SYNTAX) and an error message is given as the second argument. If false
-is returned by the error handler, processing of the wxExpr operation stops.
-
-Another way of handling errors is simply to call \helpref{wxExprDatabase::GetErrorCount}{wxexprdatabasegeterrorcount} after
-the operation, to check whether errors have occurred, instead of installing an error handler.
-If the error count is more than zero, \helpref{wxExprDatabase::Write}{wxexprdatabasewrite} and
-\rtfsp\helpref{wxExprDatabase::Read}{wxexprdatabaseread} will return false to
-the application.
-
-For example:
-
-\begin{verbatim}
-bool myErrorHandler(int err, chat *msg)
-{
- if (err == WXEXPR_ERROR_SYNTAX)
- {
- wxMessageBox(msg, "Syntax error");
- }
- return false;
-}
-
-wxExprDatabase database(myErrorHandler);
-\end{verbatim}
-
-\func{}{wxExprDatabase}{\param{wxExprType}{ type}, \param{const wxString\&}{attribute},
-\rtfsp\param{int}{ size = 500}, \param{proioErrorHandler}{ handler = 0}}
-
-Construct a new database hashed on a combination of the clause functor and
-a named attribute (often an integer identification).
-
-See above for an explanation of the error handler.
-
-\membersection{wxExprDatabase::\destruct{wxExprDatabase}}
-
-\func{}{\destruct{wxExprDatabase}}{\void}
-
-Delete the database and contents.
-
-\membersection{wxExprDatabase::Append}\label{wxexprdatabaseappend}
-
-\func{void}{Append}{\param{wxExpr* }{clause}}
-
-Append a clause to the end of the database. If the database is hashing,
-the functor and a user-specified attribute will be hashed upon, giving the
-option of random access in addition to linear traversal of the database.
-
-\membersection{wxExprDatabase::BeginFind}\label{wxexprdatabasebeginfind}
-
-\func{void}{BeginFind}{\void}
-
-Reset the current position to the start of the database. Subsequent
-\rtfsp\helpref{wxExprDatabase::FindClause}{wxexprdatabasefindclause} calls will move the pointer.
-
-\membersection{wxExprDatabase::ClearDatabase}\label{wxexprdatabasecleardatabase}
-
-\func{void}{ClearDatabase}{\void}
-
-Clears the contents of the database.
-
-\membersection{wxExprDatabase::FindClause}\label{wxexprdatabasefindclause}
-
-Various ways of retrieving clauses from the database. A return
-value of NULL indicates no (more) clauses matching the given criteria.
-Calling the functions repeatedly retrieves more matching clauses, if any.
-
-\func{wxExpr* }{FindClause}{\param{long}{ id}}
-
-Find a clause based on the special ``id'' attribute.
-
-\func{wxExpr* }{FindClause}{\param{const wxString\&}{ attribute}, \param{const wxString\&}{ value}}
-
-Find a clause which has the given attribute set to the given string or word value.
-
-\func{wxExpr*}{FindClause}{\param{const wxString\&}{ attribute}, \param{long}{ value}}
-
-Find a clause which has the given attribute set to the given integer value.
-
-\func{wxExpr*}{FindClause}{\param{const wxString\&}{ attribute}, \param{float}{ value}}
-
-Find a clause which has the given attribute set to the given floating point value.
-
-\membersection{wxExprDatabase::FindClauseByFunctor}\label{wxexprdatabasefindclausebyfunctor}
-
-\func{wxExpr*}{FindClauseByFunctor}{\param{const wxString\&}{ functor}}
-
-Find the next clause with the specified functor.
-
-\membersection{wxExprDatabase::GetErrorCount}\label{wxexprdatabasegeterrorcount}
-
-\constfunc{int}{GetErrorCount}{\void}
-
-Returns the number of errors encountered during the last read or write operation.
-
-\membersection{wxExprDatabase::HashFind}\label{wxexprdatabasehashfind}
-
-\constfunc{wxExpr*}{HashFind}{\param{const wxString\&}{ functor}, \param{long}{ value}}
-
-Finds the clause with the given functor and with the attribute specified
-in the database constructor having the given integer value.
-
-For example,
-
-\begin{verbatim}
-// Hash on a combination of functor and integer "id" attribute when reading in
-wxExprDatabase db(wxExprInteger, "id");
-
-// Read it in
-db.ReadProlog("data");
-
-// Retrieve a clause with specified functor and id
-wxExpr *clause = db.HashFind("node", 24);
-\end{verbatim}
-
-This would retrieve a clause which is written: {\tt node(id = 24, ..., )}.
-
-\func{wxExpr*}{HashFind}{\param{const wxString\&}{ functor}, \param{const wxString\&}{ value}}
-
-Finds the clause with the given functor and with the attribute specified
-in the database constructor having the given string value.
-
-\membersection{wxExprDatabase::Read}\label{wxexprdatabaseread}
-
-\func{bool}{Read}{\param{const wxString\&}{ filename}}
-
-Reads in the given file, returning true if successful.
-
-\membersection{wxExprDatabase::ReadFromString}\label{wxexprdatabasereadfromstring}
-
-\func{bool}{ReadFromString}{\param{const wxString\&}{ buffer}}
-
-Reads a Prolog database from the given string buffer, returning true if
-successful.
-
-\membersection{wxExprDatabase::Write}\label{wxexprdatabasewrite}
-
-\func{bool}{Write}{\param{FILE *}{stream}}
-
-\func{bool}{Write}{\param{const wxString\&}{ filename}}
-
-Writes the database as a Prolog-format file.
-
-
projects / wxWidgets.git / blobdiff