simple_zstring

Overview

SIMPLE_ZSTRING provides memory-efficient Unicode string handling using a dual-storage architecture. Inspired by the ZSTRING implementation in Eiffel-Loop. Characters are stored in an 8-bit primary area using ISO-8859-15 (Latin-9) encoding, with Unicode characters outside the codec range stored in a compact secondary area.

This approach provides ~70% memory savings for Western European text while supporting the full Unicode range including emoji and CJK characters. The library includes utilities for splitting, searching, escaping, formatting, and fluent string building.

Quick Start

local
    z: SIMPLE_ZSTRING
do
    create z.make_from_string ("Hello World")
    create z.make_from_utf_8 ("Bonjour le monde")
    z.append_character ((0x1F600).to_character_32)  -- Emoji
    print (z.to_string_32)
    print (z.to_utf_8)
end

Features

Dual-storage architecture (8-bit primary + 32-bit overflow)
UTF-8 encoding/decoding
ISO-8859-15 codec (Latin-9 with Euro sign)
String splitting, searching, escaping
Formatting and templates
Fluent builder pattern
Design by Contract throughout
Void-safe implementation
SCOOP-compatible

API Reference

Main dual-storage string class with 8-bit primary storage and 32-bit overflow.

Feature	Description
`make (n)`	Create with capacity for n characters
`make_empty`	Create empty string
`make_from_string (s)`	Create from general string
`make_from_utf_8 (s)`	Create from UTF-8 bytes
`item (i)`	Character at position i
`append_character (c)`	Append character at end
`to_string_32`	Convert to full Unicode STRING_32
`to_utf_8`	Convert to UTF-8 encoded STRING_8

SIMPLE_ZSTRING_SPLITTER

String splitting operations by character, string, lines, or words.

Feature	Description
`split_by_character (s, c)`	Split string by character
`split_lines (s)`	Split into lines
`split_words (s)`	Split into words

SIMPLE_ZSTRING_SEARCHER

String searching with wildcards and prefix/suffix matching.

Feature	Description
`index_of (s, pat, start)`	Find pattern starting at position
`matches_wildcard (s, pat)`	Match with * and ? wildcards
`starts_with (s, prefix)`	Check prefix

SIMPLE_ZSTRING_ESCAPER

XML, JSON, URL, CSV, and shell escaping/unescaping.

Feature	Description
`escape_xml (s)`	Escape for XML
`escape_json (s)`	Escape for JSON
`url_encode (s)`	URL percent-encoding

Installation

Add to your ECF file:

<library name="simple_zstring" location="$SIMPLE_LIBS/simple_zstring/simple_zstring.ecf"/>