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Diffstat (limited to 'src/include/xbexp.h')
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1 files changed, 0 insertions, 215 deletions
diff --git a/src/include/xbexp.h b/src/include/xbexp.h deleted file mode 100755 index 96413ac..0000000 --- a/src/include/xbexp.h +++ /dev/null @@ -1,215 +0,0 @@ -/* xbexp.h - -XBase64 Software Library - -Copyright (c) 1997,2003,2014,2022 Gary A Kunkel - -The xb64 software library is covered under the terms of the GPL Version 3, 2007 license. - -Email Contact: - - XDB-devel@lists.sourceforge.net - XDB-users@lists.sourceforge.net - -*/ - - -#ifndef __XB_EXP_H__ -#define __XB_EXP_H__ - - -// #ifdef CMAKE_COMPILER_IS_GNUCC -// #pragma interface -// #endif - - - -#ifdef XB_FUNCTION_SUPPORT -#define XB_EXP_CHAR 'C' -#define XB_EXP_DATE 'D' -#define XB_EXP_LOGICAL 'L' -#define XB_EXP_NUMERIC 'N' -#define XB_EXP_UNKNOWN 'U' -#endif - -#ifdef XB_EXPRESSION_SUPPORT - -#define XB_EXP_CONSTANT 'C' -#define XB_EXP_FUNCTION 'F' -#define XB_EXP_FIELD 'D' -#define XB_EXP_OPERATOR 'O' -#define XB_EXP_NOTROOT 'N' // not root node, needs further parsing -#define XB_EXP_PRE_OPERATOR 'B' // (B)efore) pre increment, pre decrement -#define XB_EXP_POST_OPERATOR 'A' // (A)fter) post increment, pre decrement - -#define XB_END_OF_EXPRESSION -100 - -// #define XB_UNBALANCED_PARENS -101 -// #define XB_UNBALANCED_QUOTES -102 - - -namespace xb{ - -///@cond DOXYOFF -struct XBDLLEXPORT xbExpToken { - xbString sExpression; // in - expression to pull next token from - // out - remainder of the expression after token removed - xbString sToken; // next token pulled from the expression - char cNodeType; // one of XB_EXP_CONSTANT, XB_EXP_FUNCTION, XB_EXP_FIELD, XB_EXP_OPERATOR, XB_EXP_NOTROOT - char cReturnType; // one of XB_EXP_CHAR, XB_EXP_DATE, XB_EXP_LOGICAL, XB_EXP_NUMERIC, XB_EXP_UNKNOWN - xbInt16 iSts; // return status after retrieving or attempting next token from expression - // 0 = no error - // XB_END_OF_EXPRESSION - // XB_UNBALANCED_PARENS - // XB_UNBALANCED_QUOTES - char cPrevNodeType; // previous node type - char cPrevReturnType; // previous return type - - // constructor - xbExpToken() { cNodeType = 0; cReturnType = 0; iSts = 0; cPrevNodeType = 0; cPrevReturnType = 0; } -}; -///@endcond DOXYOFF - - -/************************************************************************/ - -//! @brief Class for handling expressions. -/*! -The xbExp class is used for parsing and evaluating expression. - -The Xbase64 library includes an expression parsing module which assists -application programmers by providing a high level data manipulation tool and -also allows for building complex index keys. - -The functions included were derived from dBASE III Plus, Dbase IV and Clipper.<br><br> - -<h3>Internal fuctioning</h3> -The expression module works in two phases. Firstly, method -<em>ParseExpression</em> is called and builds an expression tree from -all the components of the expression. The tree is made up of individual -nodes. The expression is checked for valid field names, literals, -operands and functions. Any field references are resolved. If fields -are used in an expression and the database name for the field is not -included in the name with the -> operand, the routines assume the -associated database has been successfully opened. -<br> -Secondly, method <em>ProcessExpression</em> is called to process the -expression tree created by ParseExpression(). The routine parses each -node in the expression tree, executing functions, processing operands -and manipulating data to produce the desired result.<br> - -If an expression will be processed repeatedly, it is best to pre-parse the -tree using <em>ParseExpression</em>, then for each new call to the expression, -execute method <em>ProcessExpression</em> which processes the tree.<br><br> - -<h3>Expression Return Types</h3> -Expressions will return a type of CHAR, NUMERIC, DATE or LOGICAL.<br> - -An expression return type can be determined with method <em> -GetExpressionResultType</em> after parsing it.<br> - -Expressions returning a return type of CHAR are limited to a 200 byte internal -buffer. There is also a 100 byte limit for NDX index key support. If -the 200 byte limit is not large enough for your application, adjust field -<em>enum { WorkBufMaxLen = 200 };</em> in file <em>exp.h</em>.<br><br> - -<h3>Expression Functions</h3> -Each expression function also has a corresponding C++ function. It is -slightly more efficient to call the C++ functions directly, rather than -execute the expression parsing routines.<br><br> - -<h3>Expression Components</h3> -Expressions are made up of one or more tokens. A token is one of literal, -database field, operand or function. Literals are either numeric or character. -Character literals are enclosed in 'single' or "double" quotes. numeric -literals are a series of one or more contiguous numerals, ".", "+" or "-'". -<br><br> -A field is simply a field name in the default database, or is in the form -of database->fieldname. - -*/ - -class XBDLLEXPORT xbExp{ - - public: - xbExp( xbXBase * ); - xbExp( xbXBase *, xbDbf * ); - virtual ~xbExp(); - void ClearTreeHandle(); - - - #ifdef XB_DEBUG_SUPPORT - void DumpTree( xbInt16 iOption ); - void DumpToken( xbExpToken &t, xbInt16 iOption = 0 ); - #endif - - xbInt16 GetResultLen() const; - char GetReturnType() const; - xbInt16 GetBoolResult( xbBool &bResult ); - xbInt16 GetDateResult( xbDate &dtResult ); - xbInt16 GetNumericResult( xbDouble &dResult ); - xbInt16 GetStringResult( xbString &sResult ); - xbInt16 GetStringResult( char * vpResult, xbUInt32 ulLen ); - xbExpNode *GetTreeHandle(); - xbInt16 ParseExpression( const xbString &sExpression ); - xbInt16 ParseExpression( xbDbf *dbf, const xbString &sExpression ); - xbInt16 ProcessExpression(); - xbInt16 ProcessExpression( xbInt16 iRecBufSw ); - - - protected: - xbInt16 GetNextToken( xbExpToken &t ); - xbInt16 OperatorWeight( const xbString &sOperator ); - xbExpNode *GetNextNode( xbExpNode * n ) const; // traverses the tree from bottom left node, right, then up - - private: // methods - - // xbInt16 CalcExpressionResultLen(); - xbInt16 CalcFunctionResultLen( xbExpNode *n ) const; - xbInt16 CalcCharNodeLen( xbExpNode *n ); - xbInt16 CheckParensAndQuotes( const xbString &sExpression ); - xbInt16 GetExpressionResultLen() const; - - xbInt16 GetTokenCharConstant ( xbExpToken &t ); - xbInt16 GetTokenDatabaseField ( xbExpToken &t ); - xbInt16 GetTokenDateConstant ( xbExpToken &t ); - xbInt16 GetTokenFunction ( xbExpToken &t ); - xbInt16 GetTokenLogicalConstant( xbExpToken &t ); - xbInt16 GetTokenNumericConstant( xbExpToken &t ); - xbInt16 GetTokenOperator ( xbExpToken &t ); - xbInt16 GetTokenParen ( xbExpToken &t ); - - xbBool IsFunction ( const xbString &sExp, char &cReturnType ); - xbBool IsLogicalConstant ( const xbString &sExp ); - xbBool IsNumericConstant ( const xbString &sExp, char cPrevNodeType ); - xbBool IsOperator ( const xbString &sExp ); - char IsTokenSeparator ( char c ); - xbBool IsWhiteSpace ( char c ); - - xbInt16 ParseExpression ( const xbString &sExpression, xbInt16 iWeight ); - xbInt16 ParseExpressionConstant( xbExpToken &t, xbExpNode *n ); - xbInt16 ParseExpressionFunction( xbExpToken &t, xbExpNode *n, xbInt16 iWeight ); - xbInt16 ParseExpressionFunctionParms( const xbString &sParms, xbLinkList<xbString> &llParms ); - xbInt16 ParseExpressionField ( xbExpToken &t, xbExpNode *n ); - xbInt16 ParseExpressionOperator( xbExpToken &t, xbExpNode *n, xbInt16 iWeight ); - - xbInt16 ProcessExpressionFunction( xbExpNode *n, xbInt16 iRecBufSw = 0 ); - xbInt16 ProcessExpressionOperator( xbExpNode *n ); - - private: // fields - xbXBase *xbase; - xbDbf *dbf; - xbExpNode *nTree; // pointer to tree of expNodes - // xbInt16 iExpLen; // size of expression result - - -}; - -/* Expression handler */ - - -}; -#endif // XB_EXPRESSION_SUPPORT -#endif // __XB_EXP_H__ - - |