CattleTape

CattleTape — Infinite-length memory tape

Functions

Properties

gchar current-value Read / Write

Types and Values

struct CattleTape

Object Hierarchy

    GObject
    ╰── CattleTape

Includes

#include <cattle/cattle.h>

Description

A CattleTape represents an infinte-length memory tape, which is used by a CattleInterpreter to store its data. The tape contains a virtually infinte number of memory cells, each one able to store a single byte.

A tape supports three kinds of operations: reading the value of the current cell, updating the value of the current cell (either by increasing/decreasing it or by setting it to a certain value), and moving the current cell pointer (either to the left or to the right).

The tape grows automatically as more cells are needed, the only limit being the amount of available memory. It is possible to check if the current cell is at the beginning or at the end of the tape using cattle_tape_is_at_beginning() and cattle_tape_is_at_end().

Functions

cattle_tape_new ()

CattleTape *
cattle_tape_new (void);

Create and initialize a new memory tape.

Returns

a new CattleTape.

[transfer full]


cattle_tape_set_current_value ()

void
cattle_tape_set_current_value (CattleTape *tape,
                               gint8 value);

Set the value of the current cell.

Accepted values range from G_MININT8 to G_MAXINT8.

Parameters

tape

a CattleTape

 

value

the current cell's new value

 

cattle_tape_get_current_value ()

gint8
cattle_tape_get_current_value (CattleTape *tape);

Get the value of the current cell. See cattle_tape_set_current_value().

Parameters

tape

a CattleTape

 

Returns

the value of the current cell


cattle_tape_increase_current_value ()

void
cattle_tape_increase_current_value (CattleTape *tape);

Increase the value in the current cell by one.

Parameters

tape

a CattleTape

 

cattle_tape_increase_current_value_by ()

void
cattle_tape_increase_current_value_by (CattleTape *tape,
                                       gulong value);

Increase the value in the current cell by value .

Increasing the value this way is much faster than calling cattle_tape_increase_current_value() multiple times.

Parameters

tape

a CattleTape

 

value

increase amount

 

cattle_tape_decrease_current_value ()

void
cattle_tape_decrease_current_value (CattleTape *tape);

Decrease the value in the current cell by one.

Parameters

tape

a CattleTape

 

cattle_tape_decrease_current_value_by ()

void
cattle_tape_decrease_current_value_by (CattleTape *tape,
                                       gulong value);

Decrease the value in the current cell by value .

Decreasing the value this way is much faster than calling cattle_tape_decrease_current_value() multiple times.

Parameters

tape

a CattleTape

 

value

decrease amount

 

cattle_tape_move_left ()

void
cattle_tape_move_left (CattleTape *tape);

Move tape one cell to the left.

If there are no memory cells on the left of the current one, one will be created on the fly.

Parameters

tape

a CattleTape

 

cattle_tape_move_left_by ()

void
cattle_tape_move_left_by (CattleTape *tape,
                          gulong steps);

Move tape steps cells to the left.

Moving this way is much faster than calling cattle_tape_move_left() multiple times.

Parameters

tape

a CattleTape

 

steps

number of steps

 

cattle_tape_move_right ()

void
cattle_tape_move_right (CattleTape *tape);

Move tape one cell to the right.

If there are no memory cells on the right of the current one, one will be created on the fly.

Parameters

tape

a CattleTape

 

cattle_tape_move_right_by ()

void
cattle_tape_move_right_by (CattleTape *tape,
                           gulong steps);

Move tape steps cells to the right.

Moving this way is much faster than calling cattle_tape_move_right() multiple times.

Parameters

tape

a CattleTape

 

steps

number of steps

 

cattle_tape_is_at_beginning ()

gboolean
cattle_tape_is_at_beginning (CattleTape *tape);

Check if the current cell is the first one of tape .

Since the tape grows automatically as more cells are needed, it is possible to move left from the first cell.

Parameters

tape

a CattleTape

 

Returns

TRUE if the current cell is the first one, FALSE otherwise


cattle_tape_is_at_end ()

gboolean
cattle_tape_is_at_end (CattleTape *tape);

Check if the current cell is the last one of tape .

Since the tape grows automatically as more cells are needed, it is possible to move right from the last cell.

Parameters

tape

a CattleTape

 

Returns

TRUE if the current cell is the last one, FALSE otherwise


cattle_tape_push_bookmark ()

void
cattle_tape_push_bookmark (CattleTape *tape);

Create a bookmark to the current tape position and save it on the bookmark stack.

Parameters

tape

a CattleTape

 

cattle_tape_pop_bookmark ()

gboolean
cattle_tape_pop_bookmark (CattleTape *tape);

Restore the previously-saved tape position. See cattle_tape_push_bookmark().

Parameters

tape

a CattleTape

 

Returns

FALSE if the bookmarks stack is empty, TRUE otherwise

Types and Values

struct CattleTape

struct CattleTape;

Opaque data structure representing a memory tape. It should never be accessed directly.

Property Details

The “current-value” property

  “current-value”            gchar

Value of the current cell.

Changes to this property are not notified.

Owner: CattleTape

Flags: Read / Write

Default value: 0