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126 lines
5.4 KiB
Plaintext
126 lines
5.4 KiB
Plaintext
Sta Functions
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This module contains extended stack manipulation functions.
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Usage: at the beginning of the program use the directives
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#include <stddef.h02>
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#include <memory.h02>
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#include <string.h02>
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#include <stack.h02>
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#include <stackx.h02>
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The following application functions are defined:
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r = stkstr(&s); Stack String: Creates a new entry at the end of
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the stack consisting the characters in string
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s, including the terminating ASCII null. This
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ensures that when the entry is popped off the
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stack, the destination string will be properly
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terminated.
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If the string is empty or the bew entry would
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overflow the end of the stack space, no entry is
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created and a value of 0 is returned. Otherwise,
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the number of bytes in the new entry is returned.
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Note: Calls the strlen function, then calls the
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stkpsh function.
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r = stktop(&m); Stack Top: Copies the bytes from the last entry of
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the stack into array m and leaves the entry on the
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stack.
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If the stack is empty, the value 0 is returned.
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Otherwise, the number of bytes in the entry is
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returned.
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Note: Calls stkpop, then restores stklo and stkhi
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to their prior values.
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r = stkdup(); Stack Duplicate: Creates a new entry at the end of
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the stack consisting of the bytes in the last entry
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of the stack.
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If the stack is empty or the new entry would
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overflow the end of the stack space, no entry is
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created and a value of 0 is returned. Otherwise,
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the number of bytes in the new entry is returned.
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Note: Sets dstlo and dsthi to the stklo and stkhi,
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sets srclo and srchi to point to the beginning
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of the last entry, updates stklo and stkhi, then
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calls the memcpy function.
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r = stkovr(); Stack Over: Creates a new entry at the end of
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the stack consisting of the bytes in the second
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to last entry of the stack.
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If there are less than two entries in the stack
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or the new entry would overflow the end of the
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stack space, no entry is created and a value of
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0 is returned. Otherwise, the number of bytes in
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the new entry is returned.
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Note: Sets dstlo and dsthi to the stklo and stkhi,
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sets srclo and srchi to point to the beginning
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of the second to last entry, updates stklo and
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stkhi, then calls the memcpy function.
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r = stkswp(); Stack Swap: Moves the last entry in the stack to
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the second to last position and the second to
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last entry to the last position.
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If there are less than two entries in the stack
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or there is not enough room in the stack space
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to make a copy of the second to last entry, the
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entries are not swapped and a value of 0 is
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returned. Otherwise, the number of bytes in the
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new last entry is returned.
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Note: Calls stkovr, creating a copy of the second
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to last stack entry, restores stklo and stkhi to
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their original values, then calls the memcpy twice.
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*,m,l = stkptr(); Stack Pointer: Returns the address contained in
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the stack pointer as the most significant byte
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and the least significant byte.
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This is a utility function not normally used in
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application code.
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Note: Gets variables stkslo and stkshi.
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stkset(&d); Stack Set: Sets stack pointer to address d.
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This is a utility function not normally used in
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application code.
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Note: Sets variables stkslo and stkshi.
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Note: This library expects the following functions to be defined
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memcpl Copy memory (alternate entry point)
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stkadd Add to stack pointer
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stkdrn Stack drop (alternate entry point)
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stkpsa Push entry onto stack (alternate entry point)
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stkrsp Restore Stack Pointer
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stkssp Save Stack Pointer
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strlen Get string length
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along with the zero page variable pairs
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srclo, srchi Source String Pointer
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dstlo, dsthi Destination String Pointer
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stklo, stkhi stack Pointer
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the static variables
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stkslo, stkshi Stack Start Address
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stkelo, stkehi Stack End Address
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and the transient variables
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temp0, temp1 Temporary storage
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temp2, temp3
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