2.12 Syntax Notes

SWI-Prolog uses standard `Edinburgh' syntax. A description of this syntax can be found in the Prolog books referenced in the introduction. Below are some non-standard or non-common constructs that are accepted by SWI-Prolog:

• 0'<char>
  This construct is not accepted by all Prolog systems that claim to have Edinburgh compatible syntax. It describes the ASCII value of <char>. To test whether C is a lower case character one can use between(0'a, 0'z, C).
• /* ... /* ... */ ... */
  The /* ... */ comment statement can be nested. This is useful if some code with /* ... */ comment statements in it should be commented out.

• 2.12.1 ISO Syntax Support
  • 2.12.1.1 Character Escape Syntax
  • 2.12.1.2 Syntax for Non-Decimal Numbers