List of combinational blocks

This section lists combinational blocks offered by the edzed library.

Conventions used in this chapter:

Only block specific parameters are listed in the signatures. In detail:

  • the mandatory positional argument name is documented in the base class Block

  • common optional keyword arguments on_output, debug, comment and x_NAME are shown only as **block_kwargs, they are documented in the base class Block too

class edzed.FuncBlock(name, *, func: Callable, unpack: bool = True, **block_kwargs)

Create a circuit block from a regular Python function func.

Note

This is the only combinational block required, because for every possible functionality a corresponding custom function can be written. All other combinational blocks exist just for convenience.

Inputs as defined by CBlock.connect()’s positional and keyword arguments will be passed to the function as its respective positional and keyword arguments. The return value of func becomes the block’s output.

When unpack is False, all positional argument will be passed as a single tuple. This allows to directly call many useful functions expecting an iterable like all() and any() (see And() and Or() helpers below), sum(), etc. In Python, it represents the difference between func(*args) when unpack is True (default) and func(args) when unpack is False.

class edzed.Not(name, **block_kwargs)

Logical NOT (Inverter). This block has exactly one unnamed input.

class edzed.And(name, **block_kwargs)

Logical AND with arbitrary number of unnamed inputs. The output is True only if all inputs are true.

And is a subclass of the FuncBlock with fixed func=all.

class edzed.Or(name, **block_kwargs)

Logical OR with arbitrary number of unnamed inputs. The output is True only if at least one input is true.

Or is a subclass of the FuncBlock with fixed func=any.

class edzed.Xor(name, **block_kwargs)

Logical XOR with arbitrary number of unnamed inputs. The output is True only if an odd number of inputs is true.

Xor is a subclass of the FuncBlock with fixed custom func.

class edzed.Compare(name, *, low, high, **block_kwargs)

A comparator with hysteresis.

This block has one unnamed input where a numeric value is expected. Internally there is a second hidden input connected to the output. Arguably, such feedback introduces some sort of state, but for practical purposes this is a combinational block.

The output is True when the input reaches the high threshold (value >= high) and is False when the input value drops below the low threshold (value < low).

When started with an input value in the zone between low and high, the output is set to True if the input value is closer to high than to low and False in the opposite case.

class edzed.Override(name, *, null_value: Any = None, **block_kwargs)

Either pass input to output unchanged or override it with a value.

A typical use-case is an on/auto/off switch.

This block has two named inputs. Usage:

edzed.Override(NAME).connect(input=block1, override=block2)
  • pass mode (output = value from block input):

    when override is equal to null_value.

  • override mode (output = value from block override):

    when override differs from null_value.