Lumesh Sys Module

Overview of the Sys Module

The Sys module provides system-level operations and environment management functionalities, including environment variable management, variable definition checks, expression quoting, error handling, and system information retrieval. All functions support pipeline operations and provide a unified error handling mechanism.

Function Overview

Environment Management Functions

These functions are used to manage system environment variables:

env - Get the root environment as a mapping

• Parameters: None
• Returns: Map - All variables in the root environment

set <var> <val> - Define a variable in the root environment

• Parameters: var (required): String - Variable name, val (required): Any - Variable value
• Returns: None

unset <var> - Remove a variable from the root environment

• Parameters: var (required): String - Name of the variable to remove
• Returns: None

Variable Check Functions

These functions are used to check the definition status of variables:

vars - Get the defined variables in the current environment

• Parameters: None
• Returns: Map - Mapping of variables in the current environment

has <var> - Check if a variable is defined in the current environment

• Parameters: var (required): String - Name of the variable to check
• Returns: Boolean - Whether the variable exists

defined <var> - Check if a variable is defined in the current environment tree

• Parameters: var (required): String - Name of the variable to check
• Returns: Boolean - Whether the variable is defined in the environment tree

Expression Operation Functions

quote <expr> - Quote an expression

• Parameters: expr (required): Expression - Expression to quote
• Returns: Quote - Quoted expression

Error Handling Functions

These functions are used for error handling and debugging:

error <msg> - Return a runtime error

• Parameters: msg (required): String - Error message
• Returns: Throws LmError::CustomError

ecodes_rt - Display runtime error codes

• Parameters: None
• Returns: Expression - List of runtime error codes

ecodes_lm - Display LmError error codes

• Parameters: None
• Returns: Expression - List of LmError error codes

System Information Functions

info - Get operating system information

• Parameters: None
• Returns: String - Operating system information string

Output Control Functions

print_tty <arg> - Print control sequences to TTY

• Parameters: arg (required): String - Content to print
• Returns: None

discard <arg> - Send data to /dev/null

• Parameters: arg (required): Any - Data to discard
• Returns: None

Notes

The Sys module is one of the core components of the Lumesh built-in module system, registered as “Sys” in the module registry. The functions in this module are primarily used for system-level operations, complementing other application-level modules such as String and Parse.

The set and unset functions in the module are also available as global built-in functions and can be used directly without the module prefix.