State Machine, Examples of Tables in Expanded YAML

# Anything on the same line after a '#' is a comment

# Tables for building logic functions

# Not, And, Or, Xor


# Not function
"not":
-
  When: {in: "on"}
  Then: {out: "off"}
-
  When: {in: "off"}
  Then: {out: "on"}


# And function
"and":
  # check state on all input terminal assertions
  # for illustrative purposes, use don't care inputs in the "When" clause
  # don't care means the "When" is true for any value of the input terminal
  # so these "When" clauses are true for any assertion on "in1" or "in2"
-
  When: {in1: "*", in2: "*"}
  State: {in1: "on", in2: "on"}
  Then: {out: "on"}
-
  When: {in1: "*", in2: "*"}
  State: {in1: "off"}
  Then: {out: "off"}
-
  When: {in1: "*", in2: "*"}
  State: {in2: "off"}
  Then: {out: "off"}


# Or function
"or":
  # check state on all input terminal assertions
  # for illustrative purposes, list "When" transition states explicitly
  # also for illustrative purposes, use sets for defining "When" transition states
  # if the input value is in the set, the "When" is true
-
  When: {in1: ["on", "off"], in2: ["on", "off"]}
  State: {in1: "on"}
  Then: {out: "on"}
-
  When: {in1: ["on", "off"], in2: ["on", "off"]}
  State: {in2: "on"}
  Then: {out: "on"}
-
  When: {in1: ["on", "off"], in2: ["on", "off"]}
  State: {in1: "off", in2: "off"}
  Then: {out: "off"}


# Xor function
"xor":
  # "in1" and "in2" are don't care in "When" - check state for any assertion
-
  When: {in1: "*", in2: "*"}
  State: {in1: "on", in2: "off"}
  Then: {out: "on"}
-
  When: {in1: "*", in2: "*"}
  State: {in1: "off", in2: "on"}
  Then: {out: "on"}
-
  When: {in1: "*", in2: "*"}
  State: {in1: "off", in2: "off"}
  Then: {out: "off"}
-
  When: {in1: "*", in2: "*"}
  State: {in1: "on", in2: "on"}
  Then: {out: "off"}


# Counter function
# Counts when something stimulates its "in" input.
# When gets an "off" on its input, resets.
# Illustrates hidden state - counts input stimulations and then sets
# out to "on", if 5 non-"off" stimulations in a row.
# Table symbols which start with an underscore are not visible as terminals.
"count5":
-
  When: {in: "off"}
  Then: {out: "off", _state: 0} # reset
-
  When: {in: "*"}
  State: {_state: 0}
  Then: {_state: 1}
-
  When: {in: "*"}
  State: {_state: 1}
  Then: {_state: 2}
-
  When: {in: "*"}
  State: {_state: 2}
  Then: {_state: 3}
-
  When: {in: "*"}
  State: {_state: 3}
  Then: {_state: 4}
-
  When: {in: "*"}
  State: {_state: 4}
  Then: {out: "on"} # stay here
-
  # If get here, state not yet initialized.
  # Act like was just in 0 state.
  When: {in: "*"}
  Then: {out: "off", _state: 1}