knit_script.knit_script_interpreter.expressions.Gauge_Expression module

Expression for getting a sheet at a gauge.

This module provides the Gauge_Expression class, which handles the creation of sheet identifiers with specific gauge configurations. It allows knit script programs to specify sheet and gauge combinations for multi-sheet knitting operations.

class Gauge_Expression(parser_node, sheet, gauge)[source]

Bases: Expression

Manages gauge expressions.

The Gauge_Expression class handles the creation of Sheet_Identifier objects with specified sheet and gauge values. It provides a way to explicitly specify both the sheet number and gauge configuration, with automatic bounds checking and fallback to context values when needed.

This expression type is essential for multi-sheet knitting operations where different sheets need to be referenced with specific gauge configurations. It ensures that sheet numbers are valid for the specified gauge and provides sensible defaults from the execution context.

_sheet

The expression that evaluates to the sheet position.

Type:: Expression

_gauge

The expression that evaluates to the number of sheets (gauge).

Type:: Expression

__init__(parser_node, sheet, gauge)[source]

Initialize the Gauge_Expression.

Parameters:

parser_node (LRStackNode) – The parser node from the parse tree.
sheet (Expression) – The expression that evaluates to the sheet position.
gauge (Expression) – The expression that evaluates to the number of sheets in the gauge configuration.

evaluate(context)[source]

Evaluate the expression to create a sheet identifier.

Evaluates the sheet and gauge expressions and creates a Sheet_Identifier with the resulting values. Provides fallback to context values when expressions evaluate to None and performs bounds checking to ensure the sheet number is valid for the gauge.

Parameters:: context (Knit_Script_Context) – The current context of the knit_script_interpreter.
Returns:: The sheet identifier with the specified sheet and gauge parameters.
Return type:: Sheet_Identifier

Note

If the sheet number is greater than or equal to the gauge, it will be automatically adjusted to gauge-1 to ensure validity.

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 evaluate methods in subclasses with appropriate error handling decorator.

This method is called whenever a class inherits from Expression. It checks if the subclass defines its own evaluate method and wraps it with the appropriate decorator.

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