Can I configure the highlighting for escaped characters in a string?

Question

Given a simple mistake like

void setup() {
 Serial.begin(9600);
}
void loop() {
 Serial.println("\"); // note: " is escaped, so this won't compile
}

This is rendered in Arduino IDE 2.0.3 as

Syntax highlighting in Arduino IDE 2.0

and the problem is hard to spot.

The Jetbrains IDEs have special highlighting for escaped characters like

Special highlighting of escape characters

which makes the problem more obvious because the two quotation marks have different color.

Any chance that this can be configured in the new Arduino IDE 2.0.3 as well?

Because it was asked in the comments: no, the syntax highlighting does not highlight the escaped character when the string is complete. The backslash and quotation mark are both still green.

Complete string

• Thomas Weller: @hcheung "\" is not a string as it does not have a closing quotation mark. \" is an escaped character in a string.
• hcheung: "\" is an escape " without closing ", you might get the correct syntax highlight if you do "\"".
• jsotola: use a text editor that supports it
• Thomas Weller: @jsotola: I'm working with children at the age of 10. I can't simply tell them to switch the editor.
• Thomas Weller: @hcheung: No, it's not highlighted when the string is complete: i.sstatic.net/Dbb6x.png

Answer 1

Any chance that this can be configured in the new Arduino IDE 2.0.3 as well?

Yes. You'll need to enable the Arduino language features provided by the language server. They're disabled by default.

• Press F1,
• Type Preferences: Open Settings (JSON),
• Press Enter,
• The settings.json file opens.

Add the following to the JSON and save it if you do not have auto-save enabled:

{
 "arduino.language.realTimeDiagnostics": true
}

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My settings.json with the Arduino language features enabled.

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Select a board. You can ignore the port selection if you like. The language feature should start, and you will see the error in the editor.

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More details on the Advanced Settings are here.

• Thomas Weller: Thanks. Undoubtedly, this is very helpful. The color of the escaped character is still the same, though.
• dankeboy36: In the JetBrains IDE, you wrote Serial.println("\"); and in the Arduino IDE Serial.println("\"); // note: " is escaped, so this won't compile. Can you please update your question about the syntax coloring in JetBrains with the longer example? Thanks! I compared the built-in C++ extension in VS Code with Arduino IDE, and they behave the same. The compiler error seems valid: Expected expression clang(expected_expression). I do not think you will be able to tweak the syntax highlighting in Arduino IDE.
• Thomas Weller: My VSCode has syntax highlighting in strings: i.sstatic.net/Tq9iS.png Haven't used it for a long time, but IMHO I only use it for Typescript, not C++, so I don't think I have any C++ specific extensions installed and it even asks me whether I want to install some..
• dankeboy36: I did another check and can confirm a bug in the Arduino IDE that does not highlight the regex matches. If there are no compiler errors, VS Code correctly highlights \d in the "\d+" string. Arduino IDE 2.0.3 fails to do it.
• dankeboy36: One more update. The regex syntax coloring works in the Arduino IDE with both the Light (Theia) and Dark (Theia) themes, not with the Arduino ones. Steps to reproduce. Your sketch: void setup() {} void loop() { Serial.println("\d"); }. \d is not highlighted. Open settings with Ctrl/⌘+,. Select one of the Theia themes from the dropdown, and close the dialog with OK. \d is highlighted. If I select any of the Arduino themes, it does not work. This is a theme bug.