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/*---------------------------------------------------------------------------*
* SR_ExpressionParser.h *
* *
* Copyright 2007, 2008 Nuance Communciations, Inc. *
* *
* Licensed under the Apache License, Version 2.0 (the 'License'); *
* you may not use this file except in compliance with the License. *
* *
* You may obtain a copy of the License at *
* http://www.apache.org/licenses/LICENSE-2.0 *
* *
* Unless required by applicable law or agreed to in writing, software *
* distributed under the License is distributed on an 'AS IS' BASIS, *
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
* See the License for the specific language governing permissions and *
* limitations under the License. *
* *
*---------------------------------------------------------------------------*/
#ifndef __SR_EXPRESSION_PARSER_H
#define __SR_EXPRESSION_PARSER_H
#include "SR_SemprocPrefix.h"
#include "SR_SemprocDefinitions.h"
#include "SR_LexicalAnalyzer.h"
#include "SR_SymbolTable.h"
#include "SR_ExpressionEvaluator.h"
#include "ptypes.h"
#include "pstdio.h"
#include "pmemory.h"
#include "ESR_ReturnCode.h"
#include "ESR_Session.h"
#include "SR_Grammar.h"
#define SR_SemprocFunctionPtr SR_GrammarDispatchFunction
/**
* States in the finite state machine used for parsing.
*/
enum
{
/**
* Initial state for a new expression
*/
LHS_REQUIRED,
/**
* Equal sign required next
*/
OP_ASSIGN_REQUIRED,
/**
* Identifier (const or rule property reference) required next
*/
IDENTIFIER_REQUIRED,
/**
* Any operand other than equal sign required next
*/
OP_ANY_REQUIRED,
};
/**
* Structure for holding function callbacks which may be registered by the programmer from the
* application, or internally as built-in functions (see ExpressionEvaluator.h)
*/
typedef struct FunctionCallback_t
{
/**
* The pointer to the function
*/
SR_SemprocFunctionPtr pfunction;
/**
* User data
*/
void* userData;
}
FunctionCallback;
/**
* The Parser.
*/
typedef struct ExpressionParser_t
{
/**
* The current state
*/
int state;
/**
* buffer for holding the token on the lhs of equal sign
*/
LCHAR lhs[MAX_STRING_LEN];
/**
* buffer for holding the operator (which may be more than 1 char in the future!!!)
*/
LCHAR op[MAX_STRING_LEN];
/**
* buffers for holding the idetifiers encountered on the rhs of this expression
*/
LCHAR identifiers[MAX_RHS_IDENTIFIERS][MAX_STRING_LEN];
/**
* the number of identifiers encountered
*/
size_t idCount;
/**
* pointer to the appropriate buffer (above) for storing the next token encountered
* which may be an operator, identifier, etc...
*/
LCHAR *ptokenBuf;
/***************************/
/* function callback stuff */
/***************************/
/**
* hashtable used for keeping track of registered function callbacks
*/
HashMap *pfunctions;
/**
* Array storing all the function callbacks
*/
FunctionCallback functions[MAX_FUNCTION_CALLBACKS];
/**
* Pointer to the next available function callback slot in the array
*/
FunctionCallback *next;
/**
* Pointer to the current function to carry out in this expression (only one per expression !!!)
* Nesting of functions is NOT SUPPORTED
*/
SR_SemprocFunctionPtr pfunction;
/**
* Reference to current user data
*/
void* userData;
/**
* The current function name
*/
LCHAR functionName[MAX_STRING_LEN];
/**
* Indicates when a function needs to be executed at the end of a statement.
*/
ESR_BOOL needToExecuteFunction;
}
ExpressionParser;
/**
* Create and Initialize.
*
* @param self pointer to the newly created parser
*/
SREC_SEMPROC_API ESR_ReturnCode EP_Init(ExpressionParser **self);
/**
* Free.
*
* @param self pointer to the parser
*/
SREC_SEMPROC_API ESR_ReturnCode EP_Free(ExpressionParser *self);
/**
* Do the parsing of the script.
* @param self pointer to the parser
* @param lexAnalyzer pointer to the lexical analyzer where the parser gets tokens from
* @param symtable pointer to the symbol table where the parser gets/sets key-value pairs
* @param evaluator pointer to the expression evaluator where calls functiosn to evaulate expressions
* @param hashmap pointer to a hashmap used to store the results of processing
*/
SREC_SEMPROC_API ESR_ReturnCode EP_parse(ExpressionParser* self, LexicalAnalyzer* lexAnalyzer,
SymbolTable* symtable, ExpressionEvaluator* evaluator,
HashMap** hashmap);
/**
* Register a function.
* @param self pointer to the parser
* @param name name of the function, as it will appear in the script
* @param data User data
* @param pfunction pointer to the function
* @return ESR_SUCCESS
*/
SREC_SEMPROC_API ESR_ReturnCode EP_RegisterFunction(ExpressionParser* self, const LCHAR* name, void* data, SR_SemprocFunctionPtr pfunction);
/**
* Lookup pointer to a registered function.
* @param self pointer to the parser
* @param name name of the function, as it will appear in the script
* @param pfunction pointer to the function
*/
SREC_SEMPROC_API ESR_ReturnCode EP_LookUpFunction(ExpressionParser* self, LCHAR* name, void** data, SR_SemprocFunctionPtr* pfunction);
#endif
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