cirq.flatten_with_params

Creates a copy of val with any symbols or expressions replaced with new symbols.

val can be a Circuit, Gate, Operation, or other type. Also transforms a dictionary of symbol values for val to an equivalent dictionary mapping the new symbols to their evaluated values.

flatten_with_params goes through every parameter in val and does the following:

  • If the parameter is a number, don't change it.
  • If the parameter is a symbol, don't change it and use the same symbol with the same value in the new dictionary of symbol values.
  • If the parameter is an expression, replace it with a symbol and use the new symbol with the evaluated value of the expression in the new dictionary of symbol values. The new symbol will be sympy.Symbol('<x + 1>') if the expression was sympy.Symbol('x') + 1. In the unlikely case that an expression with a different meaning also has the string 'x + 1', a number is appended to the name to avoid collision: sympy.Symbol('<x + 1>_1').

val The value to copy and substitute parameter expressions with flattened symbols.
params A dictionary or ParamResolver where the keys are sympy.Symbols used by val and the values are numbers.

The tuple (new value, new params) where new value is val with flattened expressions and new params is a dictionary mapping the new symbols like sympy.Symbol('<x + 1>') to numbers like params['x'] + 1.