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Teuchos - Trilinos Tools Package
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Teuchos - Trilinos Tools Package
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The main class for users to read text using TeuchosParser. More...
#include <Teuchos_Reader.hpp>
Inherited by Teuchos::DebugReader, Teuchos::MathExpr::CalcReader, Teuchos::MathExpr::SymbolSetReader, Teuchos::regex::Reader, and Teuchos::YAMLParameterList::Reader.
Public Member Functions | |
| virtual | ~Reader () |
| Virtual destructor, allows polymorphism. More... | |
| Reader (ReaderTablesPtr tables_in) | |
| Constructor: accepts an RCP to ReaderTables. More... | |
| void | read_stream (any &result, std::istream &stream, std::string const &stream_name_in) |
| The main method for reading a stream of text. More... | |
| void | read_string (any &result, std::string const &string, std::string const &string_name) |
| A convenience method for reading a string. More... | |
| void | read_file (any &result, std::string const &file_name) |
| A convenience method for reading a file. More... | |
Protected Member Functions | |
| virtual void | at_shift (any &result, int token, std::string &text) |
| User-overridable SHIFT (token) method. More... | |
| virtual void | at_reduce (any &result, int production, std::vector< any > &rhs) |
| User-overridable REDUCE (production) method. More... | |
The main class for users to read text using TeuchosParser.
This is the most important user-facing class in TeuchosParser. A Reader represents the use of a set of ReaderTables to read (parse) a given stream of text. In most cases, users should create their own class deriving from Teuchos::Reader, and override the Reader::at_shift and Reader::at_reduce methods to implement the mechanics of their custom parser.
To use Reader, it must be given an RCP to a set of ReaderTables. In most cases, ReaderTables are constructed automatically from a Language using the make_reader_tables function. Notice that ReaderTables only have to be constructed once, and can be used simultaneously by multiple Readers. A Reader can only operate on one stream of text at a time, and contains all the variable parser state.
The Reader also provides some error reporting capability. If the text stream being read is valid as defined by the Language, the Teuchos::ParserFail exception will be thrown with a descriptive string. It is strongly recommended that code using Reader catch this exception and display its what() message to the console.
Classes deriving from Teuchos::Reader are also strongly recommended to throw the Teuchos::ParserFail exception class (or a class derived from it) to indicate that the text stream being read is invalid, usually due to constraints that can't be expressed in the Teuchos::Language.
Definition at line 53 of file Teuchos_Reader.hpp.
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inlinevirtual |
Virtual destructor, allows polymorphism.
Definition at line 57 of file Teuchos_Reader.hpp.
| Teuchos::Reader::Reader | ( | ReaderTablesPtr | tables_in | ) |
Constructor: accepts an RCP to ReaderTables.
The set of streams accepted by this Reader is dictated solely by the contents of the ReaderTables, and any additional checking implemented in derived classes. ReaderTables should be constructed from a Language using make_reader_tables.
Definition at line 220 of file Teuchos_Reader.cpp.
| void Teuchos::Reader::read_stream | ( | any & | result, |
| std::istream & | stream, | ||
| std::string const & | stream_name_in | ||
| ) |
The main method for reading a stream of text.
| result | A reference to the Teuchos::any result object. If the stream is accepted, this will be the result of the Reader::at_reduce call which reduced the root nonterminal of the Language. |
| stream | The input stream of text to be read. |
| name_in | The name of the stream. This name is only used for error reporting. |
Definition at line 251 of file Teuchos_Reader.cpp.
| void Teuchos::Reader::read_string | ( | any & | result, |
| std::string const & | string, | ||
| std::string const & | string_name | ||
| ) |
A convenience method for reading a string.
This method calls Teuchos::Parser::read_stream
Definition at line 317 of file Teuchos_Reader.cpp.
| void Teuchos::Reader::read_file | ( | any & | result, |
| std::string const & | file_name | ||
| ) |
A convenience method for reading a file.
This method calls Teuchos::Parser::read_stream
Definition at line 322 of file Teuchos_Reader.cpp.
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protectedvirtual |
User-overridable SHIFT (token) method.
This method will be called when the lexer (ReaderTables::lexer) accepts a token in the text stream. The default implementation does nothing.
| result | A reference to the Teuchos::any result object. The contents of this object are user-defined, and will be passed later to the (rhs) argument of Reader::at_reduce when this token is reduced along with other Language symbols into a nonterminal. |
| token | An integer index denoting which token was accepted. This is the index of the token in the Language::tokens vector. |
| text | The full text which matched the token's regular expression. This is a non-const reference so that users may do things like move or swap it directly into the result object. Teuchos::Reader will find the longest substring accepted by the Teuchos::ReaderTables::lexer starting from its current stream position, then repeat from the new stream position. |
Definition at line 330 of file Teuchos_Reader.cpp.
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protectedvirtual |
User-overridable REDUCE (production) method.
This method will be called when the lexer (ReaderTables::lexer) accepts a token in the text stream. The default implementation does nothing.
| result | A reference to the Teuchos::any result object. The contents of this object are user-defined, and mayb be passed later to the (rhs) argument of Reader::at_reduce when this nonterminal is reduced along with other Language symbols into a nonterminal, of it will be assigned to the result value of Teuchos::Reader::read_stream itself iff the LHS of (production) is the root nonterminal. |
| token | An integer index denoting which production was reduced. This is the index of the production in the Language::productions vector. |
| text | A vector containing the result objects associated with each RHS symbol in the production. These objects are the result of either previous calls to Reader::at_shift (if their associated symbol is a token) or Reader::at_reduce (if the associated symbol is a nonterminal). This is a non-const reference so that users may do things like move or swap it (or its elements) directly into the result object. |
Definition at line 333 of file Teuchos_Reader.cpp.
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