REBOL 3 Concepts: Errors: Error Categories

Pending Revision

This document was written for R2 and has yet to be revised for R3.

There are several categories of errors.

Contents

Syntax Errors

Syntax errors occur when a script uses REBOL syntax incorrectly. For instance, if a closing bracket is missing or a string is missing its closing quote, a syntax error will occur. These errors only occur during the load or evaluation of a file or string.

Script Errors

Script errors are general run-time errors. For instance, an invalid argument to a function will cause a script error.

Math Errors

Math errors occur when a math operation cannot be processed. For instance, when attempting to divide by zero an error will occur.

Access Errors

Access errors occur when a problem occurs with a file, port or network access. For example, an access error will occur when attempting to read a file that does not exist.

User Errors

User errors are generated explicitly by a script by creating an error value and returning it.

Internal Errors

Internal errors occur within the REBOL interpreter.