knit_script.knit_script_interpreter.statements.Swap_Statement module

Statement that swaps layers between two needles.

This module provides the Swap_Statement class, which handles layer position exchanges between needles in multi-sheet gauge configurations. It supports both layer-based swapping and sheet-based swapping for complex stitch organization.

class Swap_Statement(parser_node, needles, swap_type, value)

Bases: Statement

Statement that swaps stitch layers between needles.

This statement exchanges the layer positioning of stitches either between specific layer numbers or between needles on different sheets of a multi-sheet gauge setup. The swap operation allows for complex stitch organization and layer management in advanced knitting patterns.

The statement supports two types of swapping: layer swaps that exchange positions with needles at specific layer indices,

and sheet swaps that exchange positions between corresponding needles on different sheets.

_needles

List of expressions that evaluate to needles whose layers should be swapped.

Type:

list[Expression]

_layer

Expression for layer-based swapping.

Type:

Expression | None

_sheet

Expression for sheet-based swapping.

Type:

Expression | None

__init__(parser_node, needles, swap_type, value)

Initialize a swap statement.

Parameters:

• parser_node (LRStackNode) – The parser node from the abstract syntax tree.

• needles (list[Expression]) – List of expressions that evaluate to needles whose layers should be swapped.

• swap_type (str) – Type of swap operation, either “sheet” for swapping between sheets or “layer” for swapping with specific layer positions.

• value (Expression) – Expression that evaluates to either a sheet number (for sheet swaps) or layer number (for layer swaps).

classmethod __class_getitem__(params)

Parameterizes a generic class.

At least, parameterizing a generic class is the main thing this method does. For example, for some generic class Foo, this is called when we do Foo[int] - there, with cls=Foo and params=int.

However, note that this method is also called when defining generic classes in the first place with class Foo(Generic[T]): ….

classmethod __init_subclass__(**kwargs)

Automatically wrap execute methods in subclasses with appropriate error handling and debugging decorators.

This method is called whenever a class inherits from Statement. It checks if the subclass defines its own execute method and wraps it with the appropriate decorators

Parameters:

**kwargs (Any) – Additional keyword arguments passed to super().__init_subclass__

property file_name: str | None

Returns: str | None: The file name of the knitscript program this was parsed from or None if the program was passed as a string.

property line_number: int

Get the line number of the symbol that generated this statement.

Returns:

The line number where this element appears in the source file.

Return type:

int

property local_path: str | None

Returns: str | None: The path to the directory containing the file from which this element was parsed or None if the value was parsed from a python string.

property location: Location

Get the location of this symbol in KnitScript file.

Returns:

The location of this symbol in the source file, including file name, line number, and position information.

Return type:

Location

property location_str: str

Returns: str: The string referencing the line number and possible file name information about this element.

property position_context: str

The position context string is the string from the knitscript program from which this element was parsed. The context string will begin at the start of this element and continue to the end of the line of knitscript or a semicolon on new line are reached.

Returns:

The string used to contextualize this element in the knitscript program.

Return type:

str

execute(context)

Execute the swap operation on the specified needles.

For layer swaps, finds needles with the specified layer number and swaps their positions with the target needles.

For sheet swaps, swaps layers between needles on different sheets at corresponding positions within the gauge configuration.

Parameters:

context (Knit_Script_Context) – The current execution context of the knit script interpreter.

Raises:

TypeError – If sheet or layer values are not integers.