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Common Error Patterns

Recognizing and handling frequent error scenarios improves code reliability.

Why this exists​

Certain error conditions occur commonly across programs, and standardized handling patterns prevent bugs.

How it works​

Common patterns include validation checks, resource cleanup, and graceful degradation. Use try/catch strategically around risky operations.

Examples​

# Input validation
fn processInput(input) {
  check input == null {
    throw "Input cannot be null"
  }
  check typeof(input) != "string" {
    throw "Input must be a string"
  }
  return input.toUpperCase()
}

# Resource management
fn readFile(path) {
  set file = null
  try {
    set file = open(path)
    set content = file.read()
    return content
  } catch error {
    throw "Failed to read file: " + error
  } finally {
    check file != null {
      file.close()
    }
  }
}

# Graceful degradation
fn getConfig() {
  try {
    return loadConfigFile()
  } catch error {
    say "Using default config due to: " + error
    return getDefaultConfig()
  }
}

Common mistakes​

  • Not validating inputs before processing
  • Failing to clean up resources in error paths
  • Making programs brittle by not handling expected failures