Valid Identifier Format

An identifier is a name that is used to identify various entities in a program:

  • function names

  • Labels

  • User-defined data type (struct and enum) names

An identifier must match the following regular expression.

[A-Za-z_][A-Za-z0-9_]+

The above regular expression means that an identifier has the following rules:

  • It must start with a letter or underscore.

  • It must contain at least one more letter, number, or underscore.

In addition, an identifier has the following restrictions:

  • It cannot be the same as any of the reserved keywords (see Reserved Keywords).

  • It cannot be the same as any of the axes used in the system.

  • It cannot be an axis name followed by an integer literal, e.g., X100 if there is an axis called X.

  • It cannot be any of the supported Supported G-Code Letters, or a G-code letter followed by an integer literal, such as F100.

Identifiers are case-sensitive. For example, an identifier MyLabel is treated as a different identifier than MYLABEL.