/* * $Id$ */ /* * Harbour Project source code: * Decode function * * Copyright 2006 Francesco Saverio Giudice * www - http://harbour-project.org * www - http://www.xharbour.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA (or visit the web site http://www.gnu.org/). * * As a special exception, the Harbour Project gives permission for * additional uses of the text contained in its release of Harbour. * * The exception is that, if you link the Harbour libraries with other * files to produce an executable, this does not by itself cause the * resulting executable to be covered by the GNU General Public License. * Your use of that executable is in no way restricted on account of * linking the Harbour library code into it. * * This exception does not however invalidate any other reasons why * the executable file might be covered by the GNU General Public License. * * This exception applies only to the code released by the Harbour * Project under the name Harbour. If you copy code from other * Harbour Project or Free Software Foundation releases into a copy of * Harbour, as the General Public License permits, the exception does * not apply to the code that you add in this way. To avoid misleading * anyone as to the status of such modified files, you must delete * this exception notice from them. * * If you write modifications of your own for Harbour, it is your choice * whether to permit this exception to apply to your modifications. * If you do not wish that, delete this exception notice. * */ #include "common.ch" /* PROCEDURE Main() LOCAL aArray ? "DECODE FUNCTION TESTS" // Single, return empty value ? Decode( 10 ) // A list ? Decode( 3, 1, "A", 2, "B", 3, "C" ) // A list with default ? Decode( 4, 1, "A", 2, "B", 3, "C", "X" ) // Using an array as list of values to check ? Decode( 2, { 1, "A", 2, "B", 3, "C" } ) // Using an array with default as list of values to check ? Decode( 2, { 1, "A", 2, "B", 3, "C", "X" } ) // Using an hash as list ? Decode( 2, { 1 => "A", 2 => "B", 3 => "C" } ) // Returning a codeblock ? cStr( Decode( 2, 1, {|| 1 }, 2, {|| 2 }, 3, {|| 3 } ) ) // Checking an array aArray := { 1 } ? Decode( aArray, aArray, "A", { 2 }, "B", { 3 }, "C" ) RETURN */ /****************** * Function .......: hb_Decode( , [ ]> ) ---> * Author .........: Francesco Saverio Giudice * Date of creation: 25/01/1991 * Last revision ..: 24/01/2006 1.13 - rewritten for xHarbour and renamed in hb_Decode() * * Decode a value from a list. *******************/ FUNCTION HB_Decode(...) LOCAL aParams, nParams, xDefault LOCAL xVal, cKey, xRet LOCAL aValues, aResults, n, i, nPos, nLen aParams := hb_aParams() nParams := PCount() xDefault := NIL DO CASE CASE nParams > 1 // More parameters, real case xVal := aParams[ 1 ] hb_ADel( aParams, 1, .T. ) // Resize params nParams := Len( aParams ) // if I have a odd number of members, last is default IF ( nParams % 2 != 0 ) xDefault := aTail( aParams ) // Resize again deleting last hb_ADel( aParams, nParams, .T. ) nParams := Len( aParams ) ENDIF // Ok because I have no other value than default, I will check if it is a complex value // like an array or an hash, so I can get it to decode values IF xDefault != NIL .AND. ; ( HB_ISARRAY( xDefault ) .OR. ; HB_ISHASH( xDefault ) ) // If it is an array I will restart this function creating a linear call IF HB_ISARRAY( xDefault ) .AND. Len( xDefault ) > 0 // I can have a linear array like { 1, "A", 2, "B", 3, "C" } // or an array of array couples like { { 1, "A" }, { 2, "B" }, { 3, "C" } } // first element tell me what type is // couples of values IF HB_ISARRAY( xDefault[ 1 ] ) //// If i have an array as default, this contains couples of key / value //// so I have to convert in a linear array nLen := Len( xDefault ) // Check if array has a default value, this will be last value and has a value // different from an array IF ! HB_ISARRAY( xDefault[ nLen ] ) aParams := Array( ( nLen - 1 ) * 2 ) n := 1 FOR i := 1 TO nLen - 1 aParams[ n++ ] := xDefault[ i ][ 1 ] aParams[ n++ ] := xDefault[ i ][ 2 ] NEXT aAdd( aParams, xDefault[ nLen ] ) ELSE // I haven't a default aParams := Array( Len( xDefault ) * 2 ) n := 1 FOR i := 1 TO Len( xDefault ) aParams[ n++ ] := xDefault[ i ][ 1 ] aParams[ n++ ] := xDefault[ i ][ 2 ] NEXT ENDIF ELSE // I have a linear array aParams := xDefault ENDIF // If it is an hash, translate it in an array ELSEIF HB_ISHASH( xDefault ) aParams := Array( Len( xDefault ) * 2 ) i := 1 FOR EACH cKey IN xDefault:Keys aParams[ i++ ] := cKey aParams[ i++ ] := xDefault[ cKey ] NEXT ENDIF // Then add Decoding value at beginning hb_AIns( aParams, 1, xVal, .T. ) // And run decode() again xRet := hb_ExecFromArray( @hb_Decode(), aParams ) ELSE // Ok let's go ahead with real function // Combine in 2 lists having elements as { value } and { decode } aValues := Array( nParams / 2 ) aResults := Array( nParams / 2 ) i := 1 FOR n := 1 TO nParams - 1 STEP 2 aValues[ i ] := aParams[ n ] aResults[ i ] := aParams[ n + 1 ] i++ NEXT // Check if value exists (valtype of values MUST be same of xVal, // otherwise I will get a runtime error) // TODO: Have I to check also between different valtypes, jumping different ? nPos := aScan( aValues, {| e | e == xVal } ) IF nPos == 0 // Not Found, returning default xRet := xDefault // it could be also nil because not present ELSE xRet := aResults[ nPos ] ENDIF ENDIF CASE nParams == 0 // No parameters xRet := NIL CASE nParams == 1 // Only value to decode as parameter, return an empty value of itself xRet := EmptyValue( aParams[ 1 ] ) ENDCASE RETURN xRet FUNCTION HB_DecodeOrEmpty(...) LOCAL aParams := hb_aParams() LOCAL xVal := hb_ExecFromArray( @hb_decode(), aParams ) RETURN iif( xVal == NIL, EmptyValue( aParams[ 1 ] ), xVal ) STATIC FUNCTION EmptyValue( xVal ) LOCAL xRet LOCAL cType := ValType( xVal ) SWITCH cType CASE "C" // Char CASE "M" // Memo xRet := "" EXIT CASE "D" // Date xRet := hb_SToD() EXIT CASE "L" // Logical xRet := .F. EXIT CASE "N" // Number xRet := 0 EXIT CASE "B" // code block xRet := {|| NIL } EXIT CASE "A" // array xRet := {} EXIT CASE "H" // hash xRet := { => } EXIT CASE "U" // undefined xRet := NIL EXIT CASE "O" // Object xRet := NIL // Or better another value ? EXIT OTHERWISE // Create a runtime error for new datatypes xRet := "" IF xRet == 0 // BANG! ENDIF ENDSWITCH RETURN xRet