Context: The TDM compiler is failing when attempting to compile TDM program using device specs with symbolic template parameters in operations. This is due to the compiler seeing anything that is not a string (e.g., a value or a symbolic parameter) as a hard-coded parameter, which a template parameter is not, and concludes that the values in the spec differ from the values in the program.

Description of the Change:

Template parameters are no longer seen as a hard-coded parameter type.
If a template parameter is used instead of a p-type parameter, it can still be used to validate the parameter values in the device spec if it's named the same there.

Example: The following works, with all {s} values being validated using the gate parameter range 's': [[0.0, 99999999.]]. Also works as before with non-template p-types (e.g. p0) using the same name as in the device spec.

bbt = """\
name template_td3_fake
version 1.0
target TD3_fake (shots=1)
type tdm (temporal_modes=259, copies=1)

float array p0[1, 259] =
    {s}

Sgate({s}, 0.0) | 43
"""

device_spec = {
    'layout': bbt,
    'modes': 
    {
        'spatial': 1, 
        'concurrent': 44, 
        'temporal_max': 259
    }, 
    'compiler': ['TD3_fake'], 
    'gate_parameters': 
    {
        's': [[0.0, 99999999.]], 
    }
}

Benefits: TDM and QKD programs can be be more easily run through the compiler.

Possible Drawbacks: None

Related GitHub Issues: None

Codecov Report

Merging #625 (24988b1) into master (4254e59) will increase coverage by 0.00%. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #625   +/-   ##
=======================================
  Coverage   98.55%   98.55%           
=======================================
  Files          77       77           
  Lines        8985     8987    +2     
=======================================
+ Hits         8855     8857    +2     
  Misses        130      130

Impacted Files	Coverage Δ
strawberryfields/tdm/tdmprogram.py	`98.26% <100.00%> (+0.01%)`	:arrow_up:

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XanaduAI / strawberryfields

Symbolic parameter support in TDM compiler #625

Codecov Report