Name	Name	Last commit message	Last commit date
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NAVFoundation.CsvLexer.axi	NAVFoundation.CsvLexer.axi
NAVFoundation.CsvLexer.h.axi	NAVFoundation.CsvLexer.h.axi
NAVFoundation.CsvParser.axi	NAVFoundation.CsvParser.axi
NAVFoundation.CsvParser.h.axi	NAVFoundation.CsvParser.h.axi
NAVFoundation.CsvUtils.axi	NAVFoundation.CsvUtils.axi
README.md	README.md

NAVFoundation.CsvUtils

A comprehensive, RFC 4180-compliant CSV parsing and serialization library for AMX NetLinx with extended escape sequence support.

Overview
Features
Standards Compliance
Quick Start
API Reference
- High-Level Functions
- Low-Level Components
Usage Examples
Escape Sequences
Configuration
Error Handling
Testing
Performance
Limitations

Overview

NAVFoundation.CsvUtils provides a robust solution for parsing and serializing CSV data in AMX NetLinx applications. The library is built on a three-layer architecture:

Lexer - Tokenizes CSV input into structured tokens
Parser - Transforms tokens into 2D array structures
High-Level Utils - Convenient functions for common operations

Features

✅ Core Capabilities

RFC 4180 Compliance - Full support for the CSV standard
Bidirectional - Both parsing (CSV → Array) and serialization (Array → CSV)
Quoted Fields - Handles fields containing commas, quotes, and newlines
Empty Fields - Correctly preserves empty fields and empty rows
Multiple Line Endings - Supports LF (\n), CR (\r), and CRLF (\r\n)
Whitespace Handling - Preserves quoted whitespace, trims unquoted
Quote Escaping - RFC 4180 double-quote escaping ("")
Extended Escapes - Optional backslash escape sequences (\n, \r, \t, \\, \")

🎯 Designed For

Reading CSV configuration files
Exporting data to CSV format
Processing CSV data from external systems
Generating CSV reports
Data interchange between AMX systems

Standards Compliance

RFC 4180 (Strict Compliance)

The library fully implements RFC 4180 including:

✅ CRLF line endings for serialization
✅ Optional header rows
✅ Quoted fields containing special characters
✅ Double-quote escaping within quoted fields
✅ Trailing newline handling
✅ Empty field preservation

NAVFoundation Extensions

Additional features beyond RFC 4180 for AMX development convenience:

✅ Backslash escape sequences in quoted strings
✅ LF and CR line ending parsing
✅ Flexible whitespace handling
✅ Large file support (up to 125KB input)

Quick Start

Basic Parsing

#include 'NAVFoundation.CsvUtils.axi'

define_start {
    stack_var char csvData[2048]
    stack_var char result[100][100][255]
    
    csvData = "'Name,Age,City', $0D, $0A, 'Alice,30,New York', $0D, $0A, 'Bob,25,Boston'"
    
    if (NAVCsvParse(csvData, result)) {
        // result[1][1] = 'Name'
        // result[1][2] = 'Age'
        // result[1][3] = 'City'
        // result[2][1] = 'Alice'
        // result[2][2] = '30'
        // result[2][3] = 'New York'
        // result[3][1] = 'Bob'
        // result[3][2] = '25'
        // result[3][3] = 'Boston'
    }
}

Basic Serialization

#include 'NAVFoundation.CsvUtils.axi'

define_start {
    stack_var char data[3][3][255]
    stack_var char csvOutput[2048]
    
    data[1][1] = 'Product'
    data[1][2] = 'Price'
    data[1][3] = 'Stock'
    data[2][1] = 'Widget'
    data[2][2] = '19.99'
    data[2][3] = '150'
    data[3][1] = 'Gadget'
    data[3][2] = '29.99'
    data[3][3] = '75'
    
    if (NAVCsvSerialize(data, csvOutput)) {
        // csvOutput = "Product,Price,Stock\r\nWidget,19.99,150\r\nGadget,29.99,75\r\n"
    }
}

API Reference

High-Level Functions

`NAVCsvParse`

Parse CSV string data into a 2D array.

char NAVCsvParse(char data[], char csv[][][])

Parameters:

data - Input CSV string
csv - Output 2D array (passed by reference)

Returns:

1 (true) if parsing succeeded
0 (false) if parsing failed

Example:

stack_var char input[1024]
stack_var char output[50][50][255]

input = 'a,b,c'

if (NAVCsvParse(input, output)) {
    // output[1][1] = 'a'
    // output[1][2] = 'b'
    // output[1][3] = 'c'
}

`NAVCsvSerialize`

Serialize a 2D array into CSV string format.

char NAVCsvSerialize(char data[][][], char result[])

Parameters:

data - Input 2D array
result - Output CSV string (passed by reference)

Returns:

1 (true) if serialization succeeded
0 (false) if serialization failed

Example:

stack_var char input[2][2][255]
stack_var char output[1024]

input[1][1] = 'Hello'
input[1][2] = 'World'
input[2][1] = 'Foo'
input[2][2] = 'Bar'

if (NAVCsvSerialize(input, output)) {
    // output = "Hello,World\r\nFoo,Bar\r\n"
}

Low-Level Components

Lexer Functions

Function	Description
`NAVCsvLexerInit`	Initialize lexer with source text
`NAVCsvLexerTokenize`	Tokenize source into token array
`NAVCsvLexerTokenSerialize`	Serialize token to JSON-like string (debugging)
`NAVCsvLexerGetTokenType`	Get string representation of token type

Parser Functions

Function	Description
`NAVCsvParserInit`	Initialize parser with token array
`NAVCsvParserParse`	Parse tokens into 2D array

Usage Examples

Example 1: Configuration File

// config.csv:
// ip_address,port,name
// 192.168.1.100,23,Main Controller
// 192.168.1.101,23,Backup Controller

stack_var char fileData[2048]
stack_var char config[100][3][255]

fileData = ReadFileContents('config.csv')  // Your file read function

if (NAVCsvParse(fileData, config)) {
    stack_var integer i
    
    for (i = 2; i <= length_array(config); i++) {  // Skip header row
        stack_var char ip[255]
        stack_var integer port
        stack_var char name[255]
        
        ip = config[i][1]
        port = atoi(config[i][2])
        name = config[i][3]
        
        // Use configuration...
    }
}

Example 2: Quoted Fields

stack_var char input[1024]
stack_var char data[10][5][255]

// CSV with commas and quotes in fields
input = '"Smith, John","Engineer","Says ""Hello""",30,Boston'

if (NAVCsvParse(input, data)) {
    // data[1][1] = 'Smith, John'       // Comma preserved
    // data[1][2] = 'Engineer'
    // data[1][3] = 'Says "Hello"'      // Quote unescaped
    // data[1][4] = '30'
    // data[1][5] = 'Boston'
}

Example 3: Empty Fields

stack_var char input[1024]
stack_var char data[10][5][255]

input = 'a,,c,,'  // Leading, middle, and trailing empty fields

if (NAVCsvParse(input, data)) {
    // data[1][1] = 'a'
    // data[1][2] = ''      // Empty
    // data[1][3] = 'c'
    // data[1][4] = ''      // Empty
    // data[1][5] = ''      // Empty
}

Example 4: Multi-line Fields

stack_var char input[1024]
stack_var char data[10][3][255]

input = '"Line 1', $0A, 'Line 2",Value2,Value3"

if (NAVCsvParse(input, data)) {
    // data[1][1] = "Line 1\nLine 2"  // Newline preserved in quoted field
    // data[1][2] = 'Value2'
    // data[1][3] = 'Value3'
}

Example 5: Creating CSV Report

stack_var char report[100][4][255]
stack_var char csv[10000]
stack_var integer row

row = 1

// Header
report[row][1] = 'Timestamp'
report[row][2] = 'Event'
report[row][3] = 'Status'
report[row][4] = 'Details'
row++

// Data rows
report[row][1] = '2025-10-15 14:30:00'
report[row][2] = 'System Boot'
report[row][3] = 'Success'
report[row][4] = 'All systems online'
row++

report[row][1] = '2025-10-15 14:31:15'
report[row][2] = 'User Login'
report[row][3] = 'Success'
report[row][4] = 'Administrator logged in'
row++

if (NAVCsvSerialize(report, csv)) {
    WriteFileContents('system_log.csv', csv)  // Your file write function
}

Example 6: Round-Trip Data Processing

stack_var char originalCsv[2048]
stack_var char data[50][50][255]
stack_var char modifiedCsv[2048]

// Read CSV
originalCsv = ReadFileContents('data.csv')
NAVCsvParse(originalCsv, data)

// Modify data
data[2][3] = 'UPDATED'

// Write back to CSV
NAVCsvSerialize(data, modifiedCsv)
WriteFileContents('data_modified.csv', modifiedCsv)

Escape Sequences

RFC 4180 Standard Escaping

Quotes within quoted fields are escaped by doubling:

Input:  "say ""hello"""
Output: say "hello"

NAVFoundation Backslash Escaping

Additional escape sequences supported within quoted fields:

Sequence	Result	Hex	Description
`\n`	LF	`$0A`	Line Feed (newline)
`\r`	CR	`$0D`	Carriage Return
`\t`	TAB	`$09`	Tab character
`\\`	`\`	`$5C`	Literal backslash
`\"`	`"`	`$22`	Literal quote
`\x`	`\x`	-	Unknown sequences preserved

Examples:

// Parsing with backslash escapes
Input:  "Line1\nLine2"
Output: "Line1<LF>Line2"

Input:  "Path\\File"
Output: "Path\File"

Input:  "Say \"Hi\""
Output: "Say "Hi""

Input:  "Tab\there"
Output: "Tab<TAB>here"

Compatibility Note:

Both escaping methods can be used simultaneously
"" (RFC 4180) and \" (NAVFoundation) produce identical results
External CSV parsers may not recognize backslash escapes
Use backslash escapes for AMX-internal CSV files only

Configuration

Adjustable Constants

Defined in header files - modify before including the library:

// In NAVFoundation.CsvLexer.h.axi
constant integer NAV_CSV_LEXER_MAX_TOKENS = 5000        // Max tokens (default: 5000)
constant integer NAV_CSV_LEXER_MAX_TOKEN_LENGTH = 255   // Max token length (default: 255)
constant long NAV_CSV_LEXER_MAX_SOURCE = 127500         // Max source size (default: 125KB)

// In NAVFoundation.CsvParser.h.axi
constant integer NAV_CSV_MAX_COLUMNS = 100              // Max columns (default: 100)
constant integer NAV_CSV_MAX_ROWS = 1000                // Max rows (default: 1000)
constant integer NAV_CSV_MAX_FIELD_LENGTH = 1024        // Max field length (default: 1024)

Example - Increase Limits:

// Define custom limits before including
#define NAV_CSV_MAX_COLUMNS 200
#define NAV_CSV_MAX_ROWS 5000

#include 'NAVFoundation.CsvUtils.axi'

Error Handling

Error Logging

All errors are logged via NAVLibraryFunctionErrorLog with detailed context:

ERROR:: NAVFoundation.CsvUtils.NAVCsvParse() => csv-utils.axs:: Input data is empty
ERROR:: NAVFoundation.CsvLexer.NAVCsvLexerTokenize() => csv-utils.axs:: Exceeded maximum token limit
ERROR:: NAVFoundation.CsvParser.NAVCsvParserParse() => csv-utils.axs:: Maximum column count exceeded: 100

Common Errors

Error	Cause	Solution
"Input data is empty"	Empty string passed	Check input before parsing
"Exceeded maximum token limit"	Too many tokens	Increase `NAV_CSV_LEXER_MAX_TOKENS`
"Maximum column count exceeded"	Row has too many columns	Increase `NAV_CSV_MAX_COLUMNS`
"Maximum row count exceeded"	Too many rows	Increase `NAV_CSV_MAX_ROWS`
"Lexer cursor out of bounds"	Internal error	Check for corrupted input

Return Values

Both high-level functions return boolean success/failure:

if (!NAVCsvParse(input, output)) {
    // Handle error - check diagnostics log
    NAVLog('CSV parsing failed!')
    return
}

// Success - use output

Testing

Test Coverage

The library includes comprehensive test suites:

238 total tests (100% passing)
113 lexer tests - Tokenization, escaping, edge cases
106 parser tests - Parsing, field handling, RFC 4180 compliance
10 parse tests - High-level parsing function
12 serialize tests - High-level serialization function

Running Tests

# From repository root
cd __tests__
.\build.ps1 csv-utils

# Or using genlinx directly
genlinx build __tests__\src\csv-utils.axs

Test Categories

Basic Parsing - Simple CSV structures
Empty Field Handling - Leading, trailing, middle empty fields
Quoted Fields - Quoted strings with special characters
Whitespace Handling - Space and tab preservation
Edge Cases - Unusual but valid CSV structures
RFC 4180 Compliance - Standard conformance tests
Backslash Escapes - Extension feature tests
Round-Trip - Parse → Serialize → Parse integrity

Performance

Benchmarks

Small files (< 1KB): < 10ms parsing time
Medium files (10-50KB): < 100ms parsing time
Large files (100KB+): < 500ms parsing time

Benchmarks approximate on NX-series controllers

Optimization Tips

Pre-size arrays appropriately to avoid dynamic resizing
Reuse structures - Don't recreate lexer/parser each time
Use appropriate limits - Don't over-allocate memory
Process in chunks for very large datasets
Cache parsed results rather than re-parsing

Memory Usage

Approximate memory requirements:

Lexer: ~2.5MB (5000 tokens × 255 bytes + source)
Parser: ~100KB (1000 rows × 100 columns)
Total working memory: ~3MB for typical operations

Limitations

Known Constraints

Maximum Source Size: 127,500 bytes (125KB) default
Maximum Tokens: 5,000 tokens default
Maximum Columns: 100 columns default
Maximum Rows: 1,000 rows default
Maximum Field Length: 1,024 bytes default

All limits are configurable via constants

Not Supported

❌ Streaming/incremental parsing (entire file must be in memory)
❌ Automatic type conversion (all values are strings)
❌ Column name/header extraction (treated as regular data)
❌ Comments in CSV files
❌ Custom delimiters (comma only)
❌ Variable quote characters (double-quote only)

Platform Limitations

NetLinx Constraints:
- Fixed-size arrays (no dynamic memory)
- Limited string manipulation functions
- No native CSV support
- Memory constraints on older controllers

Advanced Topics

Custom Delimiters

Not directly supported, but can be pre-processed:

// Convert pipe-delimited to CSV
data = NAVFindAndReplace(data, '|', ',')
NAVCsvParse(data, result)

Type Conversion

Manual conversion required:

stack_var char data[100][10][255]

NAVCsvParse(csvInput, data)

// Convert to appropriate types
stack_var integer age
stack_var float price
stack_var char name[100]

age = atoi(data[1][2])        // String to integer
price = atof(data[1][3])      // String to float
name = data[1][1]             // Already string

Header Row Extraction

stack_var char data[100][10][255]
stack_var char headers[10][255]
stack_var integer i

NAVCsvParse(csvInput, data)

// Extract header row
for (i = 1; i <= length_array(data[1]); i++) {
    headers[i] = data[1][i]
}

// Find column by name
define_function integer FindColumn(char headers[][255], char name[]) {
    stack_var integer i
    
    for (i = 1; i <= length_array(headers); i++) {
        if (headers[i] == name) {
            return i
        }
    }
    
    return 0
}

Troubleshooting

Problem: "Exceeded maximum token limit"

Cause: Input has more than 5,000 tokens (fields + delimiters)

Solution:

#define NAV_CSV_LEXER_MAX_TOKENS 10000
#include 'NAVFoundation.CsvUtils.axi'

Problem: Quotes not being escaped properly

Cause: Using single backslash instead of doubled quotes