Identifier

An identifier starts with an ASCII letter and may continue with letters or numbers. A single underscore can separate groups. Lowercase snake_case is the recommended convention, but uppercase letters are accepted.

Underscore rules:

• Underscores (_) can be used within the identifier
• Only a single consecutive _ is allowed (no __)
• Underscores cannot be at the start or end of the identifier
• An underscore must always be followed by a character (not at the end)

You will encounter identifiers when defining targets, phases, extensions, variables, and locals.

There are some syntax extensions for specific usages:

• Target reference identifier can start with ^ (for example ^build) - see target configuration.
• Internal extension identifier starts with @ (for example @dotnet) - see project configuration.

Examples

✅ Valid identifiers

• config - Simple identifier
• project42 - Contains numbers
• this_is_a_var - Single underscore between words
• my_var_123 - Underscore followed by numbers
• a - Single letter
• version_1_0 - Multiple single underscores
• Config - Uppercase letters are accepted, although lowercase is recommended

❌ Invalid identifiers

• _config - Cannot start with underscore
• config_ - Cannot end with underscore
• project__42 - Two consecutive underscores are not allowed
• this_is_a_var_ - Trailing underscore (underscore must be followed by a character)
• _ - Cannot be just an underscore
• var% - Invalid character %
• my-var - Hyphens are not allowed (use underscore instead)
• my.var - Dots are not allowed (use underscore instead)
• 123project - Cannot start with a number