ParseTarget.cpp

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/*----------------------------------------------------------------------------*/
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/* Copyright (c) 1995, 2004 IBM Corporation. All rights reserved.             */
/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
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/*----------------------------------------------------------------------------*/
/******************************************************************************/
/* REXX Translator                                                            */
/*                                                                            */
/* Primitive Procedure Parse Trigger Class                                    */
/*                                                                            */
/******************************************************************************/
#include <stdlib.h>
#include "RexxCore.h"
#include "StringClass.hpp"
#include "ArrayClass.hpp"
#include "RexxActivation.hpp"
#include "ParseTarget.hpp"
#include "ParseInstruction.hpp"
 
void RexxTarget::init(
    RexxObject     *_string,            /* target string                     */
    RexxObject    **_arglist,           /* argument list                     */
    size_t          _argcount,          /* size of the argument list         */
    size_t          _translate,         /* translation flag                  */
    bool            multiple,          /* have multiple strings             */
    RexxActivation *context,           /* execution context                 */
    RexxExpressionStack *s)            /* current expression stack          */
/******************************************************************************/
/* Function:  Initialize a parse target object                                */
/******************************************************************************/
{
  this->translate = _translate;         /* save the translation flag         */
  this->arglist = _arglist;             /* we have an array of strings       */
  this->argcount = _argcount;
  this->string = (RexxString *)_string; /* save the string also              */
  this->next_argument = 1;             /* start with the first argument     */
  this->stack = s;                     // save the expression stack for saving object references in
  this->stackTop = s->location();      // save the stack top for resets
  this->next(context);                 /* go perform needed resets          */
}
 
void RexxTarget::next(
    RexxActivation *context)           /* current execution context         */
/******************************************************************************/
/* Function:  Step to the "next" string to parse, resetting all of the        */
/*            cursor movement values.                                         */
/******************************************************************************/
{
    if (this->arglist != OREF_NULL)    /* have an argument list?            */
    {
        /* beyond the array bounds?          */
        if (this->next_argument > this->argcount)
        {
            this->string = OREF_NULLSTRING;  /* just use a null string            */
        }
        else
        {
            /* get the first element             */
            this->string = (RexxString *)this->arglist[this->next_argument - 1];
            if (this->string == OREF_NULL)   /* omitted argument?                 */
            {
                this->string = OREF_NULLSTRING;/* use the null string               */
            }
        }
    }
    else
    {
        if (this->next_argument != 1)      /* beyond the first argument         */
            this->string = OREF_NULLSTRING;  /* just use a null string            */
    }
    this->next_argument++;               /* bump the argument position        */
                                         /* make sure this is a string        */
    this->string = (RexxString *)REQUEST_STRING(this->string);
    if (this->translate == parse_upper)  /* need to uppercase?                */
    {
                                         /* fold it up                        */
        this->string = this->string->upper();
    }
    /* need to lowercase?                */
    else if (this->translate == parse_lower)
    {
        /* down we go                        */
        this->string = this->string->lower();
    }
 
    // reset the stack to the entry top, and push this value on to protect it.
    this->stack->setTop(this->stackTop);
    this->stack->push(string);
    // if tracing results or intermediates, show the string being parsed.
    context->traceResult(string);
    this->start = 0;                     /* start at the beginning            */
    this->pattern_end = 0;               /* no pattern done yet               */
    this->pattern_start = 0;             /* save the pattern start            */
                                         /* save the over all length          */
    this->string_length = this->string->getLength();
    this->subcurrent = 0;                /* no sub piece to process yet       */
}
 
void RexxTarget::moveToEnd()
/******************************************************************************/
/* Function:  Move the current cursor to the string end                       */
/******************************************************************************/
{
    this->start = this->pattern_end;     /* start from end of last pattern    */
                                         /* pattern at the end too            */
    this->pattern_end = this->string_length;
    /* no pattern length either          */
    this->pattern_start = this->string_length;
    this->end = this->string_length;     /* string end is at end also         */
                                         /* save the over all length          */
                                         /* no sub piece to process yet       */
    this->subcurrent = this->start;      /* set starting point                */
}
 
void RexxTarget::forward(
    stringsize_t offset)               /* offset to move                    */
/******************************************************************************/
/* Arguments:  distance to move the parse pointer                             */
/******************************************************************************/
{
    this->start = this->pattern_start;   /* start position is last position   */
    this->end = this->start + offset;    /* set the end position              */
    if (this->end >= this->string_length)/* take us past the end?             */
    {
        this->end = this->string_length;   /* just use the end position         */
    }
    if (this->end <= this->start)      /* no forward movement?              */
    {
        this->end = this->string_length;   /* just use the end position         */
        this->pattern_start = this->start; /* start here for the next one       */
    }
    else                                 /* normal movement                   */
    {
        this->pattern_start = this->end;   /* this is new start position        */
    }
                                           /* and have a zero length pattern    */
    this->pattern_end = this->pattern_start;
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
void RexxTarget::forwardLength(
    stringsize_t offset)               /* offset to move                    */
/******************************************************************************/
/* Arguments:  distance to move the parse pointer                             */
/******************************************************************************/
{
    this->start = this->pattern_start;   /* start position is last position   */
    this->end = this->start + offset;    /* set the end position              */
    if (this->end >= this->string_length)/* take us past the end?             */
    {
        this->end = this->string_length;   /* just use the end position         */
    }
    this->pattern_start = this->end;     /* this is new start position        */
                                         /* and have a zero length pattern    */
    this->pattern_end = this->pattern_start;
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
 
void RexxTarget::absolute(
    stringsize_t offset)               /* offset to move                    */
/******************************************************************************/
/* Arguments:  new parse position                                             */
/******************************************************************************/
{
    if (offset > 0)                      /* positive offset?                  */
    {
        offset--;                          /* make origin zero                  */
    }
    this->start = this->pattern_end;     /* start position is last position   */
    if ((size_t)offset <= this->start) /* backward movement?                */
    {
        this->end = this->string_length;   /* matches to the end                */
        this->pattern_start = offset;      /* pattern start is actual position  */
    }
    else                               /* forward movement                  */
    {
        this->end = offset;                /* use the specified position        */
                                           /* take us past the end?             */
        if (this->end >= this->string_length)
        {
            /* just use the end position         */
            this->end = this->string_length;
        }
        this->pattern_start = this->end;   /* this is new start position        */
    }
    /* and have a zero length pattern    */
    this->pattern_end = this->pattern_start;
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
void RexxTarget::backward(
    stringsize_t offset)               /* offset to move                    */
/******************************************************************************/
/* Arguments:  distance to move the parse pointer                             */
/******************************************************************************/
{
    this->start = this->pattern_start;   /* start position is last position   */
    this->end = this->string_length;     /* negatives always use to the end   */
    /* go past start of string?          */
    if (offset > this->pattern_start)
    {
        this->pattern_start = 0;         /* this resets to the start          */
    }
    else
    {
        this->pattern_start -= offset;   /* just back up                      */
    }
    /* and have a zero length pattern    */
    this->pattern_end = this->pattern_start;
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
 
void RexxTarget::backwardLength(
    stringsize_t offset)               /* offset to move                    */
/******************************************************************************/
/* Arguments:  distance to move the parse pointer                             */
/******************************************************************************/
{
    this->start = this->pattern_start;   /* start position is last position   */
    this->end = this->string_length;     /* negatives always use to the end   */
                                         /* go past start of string?          */
    if (offset > this->pattern_start)
    {
        this->start = 0;
    }
    else
    {
        this->start = this->pattern_start - offset;
    }
    this->end = this->pattern_start;     // the end is the starting location
                                         /* and have a zero length pattern    */
    this->pattern_end = this->pattern_start;
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
 
void RexxTarget::search(
    RexxString *needle)                /* target search string              */
/******************************************************************************/
/* Arguments:  target location string                                         */
/******************************************************************************/
{
    /* start position for strings is the */
    this->start = this->pattern_end;     /* end of the last pattern           */
                                         /* search for the string trigger     */
    this->end = this->string->pos(needle, this->start);
    if (this->end == 0)                /* not found?                        */
    {
        this->end = this->string_length;   /* that is the end position          */
                                           /* next pattern is end also          */
        this->pattern_start = this->string_length;
        /* and the end pattern is also there */
        this->pattern_end = this->string_length;
    }
    else
    {
        this->end--;                       /* convert to origin zero            */
        this->pattern_start = this->end;   /* this is the starting point        */
                                           /* end is start + trigger length     */
        this->pattern_end = this->pattern_start + needle->getLength();
    }
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
void RexxTarget::caselessSearch(
    RexxString *needle)                /* target search string              */
/******************************************************************************/
/* Arguments:  target location string                                         */
/******************************************************************************/
{
    /* start position for strings is the */
    this->start = this->pattern_end;     /* end of the last pattern           */
                                         /* search for the string trigger     */
    this->end = this->string->caselessPos(needle, this->start);
    if (this->end == 0)                /* not found?                        */
    {
        this->end = this->string_length;   /* that is the end position          */
                                           /* next pattern is end also          */
        this->pattern_start = this->string_length;
        /* and the end pattern is also there */
        this->pattern_end = this->string_length;
    }
    else
    {
        this->end--;                       /* convert to origin zero            */
        this->pattern_start = this->end;   /* this is the starting point        */
                                           /* end is start + trigger length     */
        this->pattern_end = this->pattern_start + needle->getLength();
    }
    this->subcurrent = this->start;      /* set the subpiece pointer          */
}
 
RexxString *RexxTarget::getWord()
/******************************************************************************/
/*  Returned:  Next word extracted from parsed substring                      */
/******************************************************************************/
{
    RexxString *word;                    /* extracted word                    */
    size_t  length;                      /* word length                       */
    const char *scan;                    /* scan pointer                      */
    const char *endScan;                 /* end of string location            */
 
    if (this->subcurrent >= this->end)   /* already used up?                  */
    {
        word = OREF_NULLSTRING;            /* just return a null string         */
    }
    else                               /* need to scan off a word           */
    {
        /* point to the current position     */
        scan = this->string->getStringData() + this->subcurrent;
        /* and the scan end point            */
        endScan = this->string->getStringData() + this->end;
        /* NOTE:  All string objects have a terminating NULL, so the */
        /* scan for nonblanks is guaranteed to stop before getting into */
        /* trouble, which eliminates the need to check against the */
        /* length */
        while (*scan == ' ' || *scan == '\t')
        {
            scan++;                          /* step for each match found         */
        }
        /* set the new location              */
        this->subcurrent = scan - this->string->getStringData();
        if (this->subcurrent >= this->end) /* already used up?                  */
        {
            word = OREF_NULLSTRING;          /* just return a null string         */
        }
        else                             /* have a real word                  */
        {
            /* look for the next blank           */
            endScan = NULL;
            const char *scanner = scan;
            const char *endPosition = string->getStringData() + this->end;
            while (scanner < endPosition)
            {
                if (*scanner == ' ' || *scanner == '\t')
                {
                    endScan = scanner;
                    break;
                }
                scanner++;
            }
            if (endScan == NULL)           /* no match?                         */
            {
                /* calculate the length              */
                length = this->end - this->subcurrent;
                this->subcurrent = this->end;  /* use the rest of it                */
            }
            else
            {
                /* set the new location              */
                this->subcurrent = endScan - this->string->getStringData();
                length = endScan - scan;       /* calculate from the pointers       */
            }
            /* step past terminating blank...note*/
            /* that this is done unconditionally,*/
            /* but safely, since the check at the*/
            /* start will catch the out of bounds*/
            this->subcurrent++;              /* condition                         */
                                             /* this the entire string?           */
            if (length == this->string_length)
            {
                word = this->string;           /* just return it directly           */
            }
            else
            {
                /* extract the subpiece              */
                word = new_string(scan, length);
            }
        }
    }
    return word;                         /* give this word back               */
}
 
void RexxTarget::skipWord()
/******************************************************************************/
/*  Returned:  Next word extracted from parsed substring                      */
/******************************************************************************/
{
    const char *scan;                    /* scan pointer                      */
    const char *endScan;                 /* end of string location            */
 
    if (this->subcurrent < this->end)  /* something left?                   */
    {
        /* point to the current position     */
        scan = this->string->getStringData() + this->subcurrent;
        /* and the scan end point            */
        endScan = this->string->getStringData() + this->end;
        /* NOTE:  All string objects have a terminating NULL, so the */
        /* scan for nonblanks is guaranteed to stop before getting into */
        /* trouble, which eliminates the need to check against the */
        /* length */
        while (*scan == ' ' || *scan == '\t')
        {
            scan++;                          /* step for each match found         */
        }
        /* set the new location              */
        this->subcurrent = scan - this->string->getStringData();
        if (this->subcurrent < this->end)/* something left over?              */
        {
            /* look for the next blank           */
            endScan = NULL;
            const char *scanner = scan;
            const char *endPosition = string->getStringData() + this->end;
            while (scanner < endPosition)
            {
                if (*scanner == ' ' || *scanner == '\t')
                {
                    endScan = scanner;
                    break;
                }
                scanner++;
            }
            if (endScan == NULL)             /* no match?                         */
            {
                this->subcurrent = this->end;  /* use the rest of it                */
            }
            else
            {
                /* set the new location              */
                this->subcurrent = endScan - this->string->getStringData();
            }
            /* step past terminating blank...note*/
            /* that this is done unconditionally,*/
            /* but safely, since the check at the*/
            /* start will catch the out of bounds*/
            this->subcurrent++;              /* condition                         */
        }
    }
}
 
RexxString *RexxTarget::remainder()
/******************************************************************************/
/*  Returned:  Remaining portion of parsed substring                          */
/******************************************************************************/
{
    RexxString *word;                    /* extracted word                    */
    size_t  length;                      /* length to extract                 */
 
    if (this->subcurrent >= this->end)   /* already used up?                  */
    {
        word = OREF_NULLSTRING;            /* just return a null string         */
    }
    else                               /* extract the remaining piece       */
    {
        /* calculate the length              */
        length = this->end - this->subcurrent;
        if (length == this->string_length) /* this the entire string?           */
        {
            word = this->string;             /* just return it directly           */
        }
        else                               /* need to extract a piece           */
        {
            word = this->string->extract(this->subcurrent, length);
        }
        this->subcurrent = this->end;      /* eat the remainder piece           */
    }
    return word;                         /* give this word back               */
}