bs::command_math Class Reference

Prints on stdout the result of a mathematical operation. More...

#include <command_math.h>

Inheritance diagram for bs::command_math:

Collaboration diagram for bs::command_math:

Public Member Functions
	command_math ()
	Constructs command.
shell_status	run (const std::span< const std::string > &vArgs, shell_session &oSession) const override
	Prints on stdout the result of a mathematical operation.
virtual void	msg_error_math (std::ostream &oStdErr, shell_status nStatus) const
	Displays the error message for math errors.
Public Member Functions inherited from bs::command
	command (std::string sName)
	Construct a command with a given name.
virtual	~command ()=default
	Virtual destructor.
std::string	get_name () const
	Get the command name (copy).
const std::string &	get_name_ref () const noexcept
	Get the command name (reference).

Detailed Description

Prints on stdout the result of a mathematical operation.

Syntax: math mathematics expression

Supports:

• Operators: + - * / ^ ** × ÷
• Integer numbers within the range of bc2 64 bits
• Parentheses: ( ) (and nested parentheses).
• Negative powers partially: { x != 0 } ^ { y < 0 } = 0
• Functions:
  • factorial(x)
  • abs(x): |x|
  • sign(x): x != 0: x / abs(x), x == 0: 0
  • sum(variable; start; end; step; expression) where expression is f(variable), ex: count = sum(x;1;1;100;1)
  • product(variable; start; end; step; expression) where expression is f(variable), ex: factorial = product(x;1;1;100;x)
  • Note that sum/product with same variable, the variable from the one inside will hide the variable of the one outside
  • Note that sum/product require variable names acceptable by the shell

Possible errors:

• Not an integer: bs::shell_status::SHELL_CMD_ERROR_MATH_NOT_AN_INTEGER
• Overflow: bs::shell_status::SHELL_CMD_ERROR_MATH_OVERFLOW
• Underflow: bs::shell_status::SHELL_CMD_ERROR_MATH_UNDERFLOW
• Division by 0: bs::shell_status::SHELL_CMD_ERROR_MATH_DIV_BY_ZERO
• Power of 0^0: bs::shell_status::SHELL_CMD_ERROR_MATH_POW_0_EXP_0
• Factorial of negative: bs::shell_status::SHELL_CMD_ERROR_MATH_FACTORIAL_NEGATIVE
• Malformed expression: bs::shell_status::SHELL_CMD_ERROR_MATH_MALFORMED_EXPRESSION
• Maximum depth reached (512 as of now): bs::shell_status::SHELL_CMD_ERROR_MATH_MAX_DEPTH_REACHED
• Invalid variable name (on function variable): bs::shell_status::SHELL_CMD_ERROR_MATH_INVALID_VARIABLE_NAME
• Sequence logic error if sequence function is invalid: bs::shell_status::SHELL_CMD_ERROR_MATH_SEQ_ITERATION_LOGIC

Member Function Documentation

msg_error_math()

void bs::command_math::msg_error_math ( std::ostream &  oStdErr, shell_status  nStatus  ) const

virtual

Displays the error message for math errors.

Can be overwritten with custom behaviour.

Parameters

oStdErr	Error output stream
nStatus	Status code

run()

shell_status bs::command_math::run ( const std::span< const std::string > &  vArgs, shell_session &  oSession  ) const

overridevirtual

Prints on stdout the result of a mathematical operation.

Parameters

vArgs	Arguments for the command.
oSession	The shell session context.

Returns

Status of command execution.

Implements bs::command.

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The documentation for this class was generated from the following files:

• /home/runner/work/bashspark/bashspark/include/BashSpark/command/command_math.h
• /home/runner/work/bashspark/bashspark/src/BashSpark/command/command_math.cpp