ZStringBuilder

SwiftForth SWOOP class for building strings large or small, inspired by .NET StringBuilder class

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** by Robert Dickow, aka Budsy **

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License

This project is licensed under the MIT License. See the LICENSE file for details.

Requirements

SwiftForth 32/64 or compatible Forth system

Tested with:

• SwiftForth 4.1.9

Features

Manages an expandable string in a system RAM buffer Dynamically and transparently expands storage as strings are appended Easy words to initialize, free and clear the buffer Unlimited string size (except by available RAM of course.)

Files

• zstring-builder-class.f - class code.
• test.f - simple test.
• README.md - this readme file.

general usage:

• ... declare a class instance.
• ... call INIT before doing any other operations.
• ... will initialize the string buffer with 0 length string.
• ... APPEND or APPENDLINE zstrings to end of current string.
• ... GET the current zstring as desired for printing, etc.
• ... or TYPE to print the string
• ... CLEAR for resetting to empty string and for rebuilding if desired.

• (does not FREE the memory)
  

• ... FREE when done. Must call INIT again to reuse instance.

available class methods (words):

INIT ( -- ) \ initialize by creating a 0 len string in new allocated buffer.
             \ call init after FREE if reuse is desired.
CLEAR ( -- ) \  clear the string to empty string, but still leaves allocated memory
FREE  ( -- ) \ cleanup using this. Class may still be INITted again for reuse.
APPEND ( zptr -- ) \ add a string to the end of current string.
APPENDLINE ( zptr -- ) \ adds a string with new line appended.
GET    ( -- zptr ) \ returns the address of the current zstring buffer
   Throws exception AllocError if problem allocating memory occurs.
LENGTH ( -- n ) \ length of instance string in characters
TYPE   ( -- )  \ prints the current string to the console.

Running Demo in SwiftForth IDE

include demo

Example declaration and interactive usage:

include ZSTRING-BUILDER-CLASS

zstring-builder builds str \ declare static instance 'str' word

str init \ first call the init method
z" Hello World!" str appendline \ append string to empty buffer
str length cr .  \ print the length of the string.
str type \ prints the string to the console.
z"  No worries " str append
z" at all!" str appendline
str type
str free \ frees allocated memory. Do when done to free allocated memory resources.

See SwiftForth documentation for how to use dynamic object declaration and use.