C++ Editor Features

The Autonomy Edge IDE provides a rich editing experience for C++ function blocks. When you open a C++ function block, you get syntax highlighting, intelligent code completion, signature help, and code snippets that help you write correct code faster.

Editor Basics

The C++ code editor provides:

• Syntax highlighting: Keywords, types, strings, numbers, comments, and preprocessor directives are color-coded for easy reading.
• Bracket matching: Matching braces, parentheses, and brackets are highlighted when your cursor is next to one.
• Auto-closing: Opening braces, parentheses, brackets, and quotes automatically insert their closing counterpart.
• Indentation: The editor automatically indents code inside blocks, functions, and control structures.
• Code folding: Collapse and expand function bodies, conditional blocks, and other code regions.

These features work out of the box with no configuration required.

Code Completion

The IDE includes a comprehensive completion provider that offers intelligent suggestions as you type. Press Ctrl+Space (or Cmd+Space on macOS) to manually trigger the completion menu at any time.

The completion provider draws from four sources:

1. Standard C/C++ Library Functions

The editor suggests functions from commonly used standard library headers:

stdio.h: Standard input/output:

stdlib.h: General utilities:

string.h: String and memory operations:

math.h: Mathematical functions:

2. Arduino API Functions

When your project targets Arduino-compatible hardware, the completion provider also suggests Arduino API functions:

Core Functions:

Serial Communication:

I2C (Wire Library):

SPI Library:

EEPROM Library:

3. Code Snippets

The editor provides code snippets for common C++ patterns. Type a snippet prefix and select it from the completion menu to insert a template with tab stops.

For example, typing for and selecting the snippet produces:

cpp
for (int i = 0; i < count; i++) {
    // body
}

The cursor is positioned at the first tab stop (i), and you can press Tab to jump to the next editable position.

4. Local Variable Parsing

The completion provider analyzes your code in real time and extracts locally declared variables. Variables you define in your C++ code (not just those in the Variables Table) appear in the completion suggestions.

The parser recognizes common declaration patterns including:

• Simple declarations: int x = 0;
• Pointer declarations: float *ptr;
• Array declarations: int buffer[100];
• Const declarations: const int MAX_SIZE = 50;

Signature Help

When you type an opening parenthesis ( after a known function name, the editor displays a signature help popup showing the function's parameters, their types, and a brief description. As you type each argument and add commas, the popup highlights the current parameter.

For example, typing pinMode( displays:

code
pinMode(pin: uint8_t, mode: uint8_t)
  pin  - The pin number to configure
  mode - INPUT, OUTPUT, or INPUT_PULLUP

Signature help is available for standard C/C++ library functions and Arduino API functions.

Tips for Effective C++ Editing

Use Tab Completion

Instead of typing full function names, type the first few characters and press Tab or Enter to accept the highlighted completion. This reduces typos and speeds up coding.

Leverage the Variables Table

Variables declared in the Variables Table are always available in your code by name. If a variable name doesn't autocomplete, check that it's properly defined in the Variables Table.

Watch for Type Mismatches

The IEC types map to specific C types (see C++ Function Block Structure for the full table). Common pitfalls:

• IEC_BOOL is uint8_t, not C++ bool. Use 0 and 1, not false and true.
• IEC_INT is int16_t (16-bit), not int (typically 32-bit). Arithmetic overflow can occur at 32,767.
• IEC_REAL is float (32-bit), not double. Use f suffix for float literals (e.g., 3.14f) to avoid implicit conversion warnings.

Keep Code Organized

Even though all your C++ code goes into a single loop() function, you can define helper functions and call them from loop():

cpp
float clamp(float value, float minVal, float maxVal) {
    if (value < minVal) return minVal;
    if (value > maxVal) return maxVal;
    return value;
}

void setup() {
    OUTPUT = 0.0;
}

void loop() {
    OUTPUT = clamp(INPUT * GAIN, 0.0f, 100.0f);
}

Helper functions, global variables, struct definitions, and #define constants can all be placed above setup() and loop().

Use Preprocessor Guards for Arduino Code

If your function block might run on both Arduino and non-Arduino targets, wrap Arduino-specific code in #ifdef ARDUINO guards:

cpp
void setup() {
    #ifdef ARDUINO
    Serial.begin(9600);
    pinMode(LED_PIN, OUTPUT);
    #endif
}

This prevents build errors when targeting Linux or other non-Arduino platforms.

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What's Next?

Learn how to declare and manage variables for all POU types, including the variable classes, data types, and editor features: Local Variables.