/*****************************************************************************

	ExeF()

	This function executes a F command.
	nF_	Destructive search and replace
	F'	Flow to end of conditional
	F<	Flow to start of iteration
	F>	Flow to end of iteration
	F|	Flow to ELSE part of conditional
	m,nFB	Search between locations m and n
	nFB	Search, bounded by n lines
	m,nFC	Search and replace between locations m and n
	nFC	Search and replace over n lines
	nFD	Search and delete string
	nFK	Search and delete intervening text
	nFN	Global string replace
	FR	Replace last string
	nFS	Local string replace

*****************************************************************************/

#include "zport.h"		/* define portability identifiers */
#include "tecoc.h"		/* define general identifiers */
#include "defext.h"		/* define external global variables */
#include "chmacs.h"		/* define character processing macros */
#include "deferr.h"		/* define identifiers for error messages */

#if USE_PROTOTYPES
static DEFAULT ExeFBr(void);
static DEFAULT ExeFC(void);
static DEFAULT ExeFD(void);
static DEFAULT ExeFGt(void);
static DEFAULT ExeFK(void);
static DEFAULT ExeFLs(void);
static DEFAULT ExeFN(void);
static DEFAULT ExeFR(void);
static DEFAULT ExeFS(void);
static DEFAULT ExeFSQ(void);
static DEFAULT ExeFUn(void);
#endif

/*****************************************************************************

	ExeFBr()

	This function executes a F| (F-bar) command.

*****************************************************************************/

static DEFAULT ExeFBr()			/* execute an F| command */
{
	DBGFEN(1,"ExeFBr",NULL);

	CmdMod = '\0';				/* clear modifiers flags */
	EStTop = EStBot;			/* clear expression stack */

	DBGFEX(1,DbgFNm,"FlowEE()");
	return FlowEE();
}

/*****************************************************************************

	ExeFC()

	This function executes a FC command.

*****************************************************************************/

static DEFAULT ExeFC()			/* execute an FC command */
{
	DBGFEN(1,"ExeFC",NULL);

	if (CmdMod & DCOLON) {			/* if it's ::FC */
		ErrStr(ERR_ILL, "::FC");	/* illegal command "::FC" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	SrcTyp = FB_SEARCH;
	if (Replac() == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFD()

	This function executes a FD command.

*****************************************************************************/

static DEFAULT ExeFD()			/* execute an FD command */
{
	DBGFEN(1,"ExeFD",NULL);

/*
 * The command m,nFD is illegal: the user should use m,nFB
 */

	if (CmdMod & MARGIS) {			/* if it's m,nFD */
		ErrStr(ERR_ILL, "m,nFD");	/* illegal command "m,nFD" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (CmdMod & DCOLON) {			/* if it's ::FD */
		ErrStr(ERR_ILL, "::FD");	/* illegal command "::FD" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	SrcTyp = S_SEARCH;
	if (Search(FALSE) == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (Matchd) {				/* if successful search */
		GapBeg += RefLen;		/* delete found string */
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFGt()

	This function executes a F> command.

*****************************************************************************/

static DEFAULT ExeFGt()			/* execute an F> command */
{
	DBGFEN(1,"ExeFGt",NULL);

	if (LStTop == LStBot) {			/* if not in a loop */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (FlowEL() == FAILURE) {		/* flow to end-of-loop */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}
	CBfPtr--;				/* backup before the ">" */
	LStTop++;				/* cancel what FlowEL did */
	CmdMod = '\0';				/* clear modifiers flags */
	EStTop = EStBot;			/* clear expression stack */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFK()

	This function executes a FK command.

*****************************************************************************/

static DEFAULT ExeFK()			/* execute an FK command */
{
	DBGFEN(1,"ExeFK",NULL);

	if (CmdMod & MARGIS) {			/* if it's m,nFK */
		ErrStr(ERR_ILL, "m,nFK");	/* illegal command "m,nFK" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (CmdMod & DCOLON) {			/* if it's ::FK */
		ErrStr(ERR_ILL, "::FK");	/* illegal command "::FK" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	SrcTyp = FK_SEARCH;

	if (Search(FALSE) == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFLs()

	This function executes a F< command.

*****************************************************************************/

static DEFAULT ExeFLs()			/* execute an F< command */
{
	DBGFEN(1,"ExeFLs",NULL);

	CmdMod = '\0';				/* clear modifiers flags */
	EStTop = EStBot;			/* clear expression stack */
	CBfPtr = (LStTop == LStBot) ? CStBeg-1 : LStack[LStTop].LAddr;

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFN()

	This function executes a FN command.

*****************************************************************************/

static DEFAULT ExeFN()			/* execute an FN command */
{
	DBGFEN(1,"ExeFN",NULL);

/*
 * The command m,nFN is illegal: the user should use m,nFC
 */

	if (CmdMod & MARGIS) {			/* if it's m,nFN */
		ErrStr(ERR_ILL, "m,nFN");	/* illegal command "m,nFN" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (CmdMod & DCOLON) {			/* if it's ::FN */
		ErrStr(ERR_ILL, "::FN");	/* illegal command "::FN" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	SrcTyp = N_SEARCH;

	if (Replac() == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFR()

	This function executes a FR command.

*****************************************************************************/

static DEFAULT ExeFR()			/* execute an FR command */
{
	DBGFEN(1,"ExeFR",NULL);

	if ((GapBeg-RefLen) < EBfBeg) {		/* if out of range */
		ErrMsg(ERR_DTB);		/* DTB = "delete too big" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	GapBeg += RefLen;			/* delete */

	CmdMod = (CmdMod & COLON);		/* retain only colon bit */
	EStTop = EStBot;			/* clear expression stack */

	DBGFEX(1,DbgFNm,"ExeI()");
	return ExeI();
}

/*****************************************************************************

	ExeFS()

	This function executes a FS command.

*****************************************************************************/

static DEFAULT ExeFS()			/* execute an FS command */
{
	DBGFEN(1,"ExeFS",NULL);

/*
 * The command m,nFS is illegal: the user should use m,nFC
 */

	if (CmdMod & MARGIS) {			/* if it's m,nFS */
		ErrStr(ERR_ILL, "m,nFS");	/* illegal command "m,nFS" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

/*
 * If it's ::FStext$,  it's a compare,  not a search.  The text argument is
 * compared to the characters immediately following the character pointer.
 * It returns -1 if the strings match, else 0.  A ::FStext$ command is
 * equivalent to a .,.+1:FCtext$ command, so that's the way it's implemented.
 */

	if (CmdMod & DCOLON) {			/* if it's ::FS */
		if (CmdMod & MARGIS) {		/* if it's m,n::FS */
			ErrStr(ERR_ILL, "m,n::FS");
			DBGFEX(1,DbgFNm,"FAILURE");
			return FAILURE;
		}
		if (EStTop > EStBot) {		/* if it's n::FS */
			ErrStr(ERR_ILL, "n::FS");
			DBGFEX(1,DbgFNm,"FAILURE");
			return FAILURE;
		}
		if (GapEnd == EBfEnd) {		/* if nothing to search */
			CmdMod = '\0';		/* clear modifiers flags */
			DBGFEX(1,DbgFNm,"PushEx(0)");
			return PushEx(0L,OPERAND);
		}
		CmdMod &= ~DCOLON;		/* clear double-colon bit */
		CmdMod |= COLON;		/* set colon bit */
		CmdMod |= MARGIS;		/* set m defined bit */
		MArgmt = GapBeg - EBfBeg;	/* set m */
		if (PushEx((LONG)((GapBeg-EBfBeg)+1),OPERAND) == FAILURE) {
			DBGFEX(1,DbgFNm,"FAILURE, PushEx() failed");
			return FAILURE;
		}
		DBGFEX(1,DbgFNm,"ExeFC()");
		return ExeFC();			/* execute FC command */
	}

	SrcTyp = S_SEARCH;
	if (Replac() == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE, Replac() failed");
		return FAILURE;
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeFSQ()

	This function executes a F' command.

*****************************************************************************/

static DEFAULT ExeFSQ()				/* execute an F' command */
{
	DBGFEN(1,"ExeFSQ",NULL);

	CmdMod = '\0';				/* clear modifiers flags */
	EStTop = EStBot;			/* clear expression stack */

	DBGFEX(1,DbgFNm,"FlowEC()");
	return FlowEC();
}

/*****************************************************************************

	ExeFUn()

	This function executes a F_ command.

*****************************************************************************/

static DEFAULT ExeFUn()				/* execute an F_ command */
{
	DBGFEN(1,"ExeFUn",NULL);

/*
 * The command m,nF_ is illegal: the user should use m,nFC
 */


	if (CmdMod & MARGIS) {			/* if it's m,nF_ */
		ErrStr(ERR_ILL, "m,nF_");	/* illegal command "m,nF_" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	if (CmdMod & DCOLON) {			/* if it's ::F_ */
		ErrStr(ERR_ILL, "::F_");	/* illegal command "::F_" */
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	SrcTyp = U_SEARCH;

	if (Replac() == FAILURE) {
		DBGFEX(1,DbgFNm,"FAILURE");
		return FAILURE;
	}

	CmdMod = '\0';				/* clear modifiers flags */

	DBGFEX(1,DbgFNm,"SUCCESS");
	return SUCCESS;
}

/*****************************************************************************

	ExeF()

	This function executes an F command.

*****************************************************************************/

DEFAULT ExeF()				/* execute one of the F commands */
{
	if (IncCBP() == FAILURE) {
		return FAILURE;
	}

	switch (To_Upper(*CBfPtr)) {
          case 'S':  return ExeFS();
	  case 'N':  return ExeFN();
	  case 'D':  return ExeFD();
	  case 'R':  return ExeFR();
	  case 'B':  return ExeFB();
	  case 'C':  return ExeFC();
	  case 'K':  return ExeFK();
	  case '_':  return ExeFUn();
	  case '>':  return ExeFGt();
	  case '<':  return ExeFLs();
	  case '\'': return ExeFSQ();
	  case '|':  return ExeFBr();
	  default:   ErrChr(ERR_IFC, *CBfPtr);
		     return FAILURE;
	}
}