public static StringDistribution SubAverageConditional(StringDistribution str, int start, int minLength, int maxLength)
{
Argument.CheckIfNotNull(str, "str");
Argument.CheckIfInRange(start >= 0, "start", "Start index must be non-negative.");
Argument.CheckIfInRange(minLength >= 0, "minLength", "Min length must be non-negative.");
Argument.CheckIfInRange(maxLength >= 0, "maxLength", "Max length must be non-negative.");
if (str.IsPointMass)
{
var strPoint = str.Point;
var alts = new HashSet <string>();
for (int length = minLength; length <= maxLength; length++)
{
var s = strPoint.Substring(start, Math.Min(length, strPoint.Length));
alts.Add(s);
}
return(StringDistribution.OneOf(alts));
}
var anyChar = StringAutomaton.ConstantOnElement(1.0, ImmutableDiscreteChar.Any());
var transducer = StringTransducer.Consume(StringAutomaton.Repeat(anyChar, minTimes: start, maxTimes: start));
transducer.AppendInPlace(StringTransducer.Copy(StringAutomaton.Repeat(anyChar, minTimes: minLength, maxTimes: maxLength)));
transducer.AppendInPlace(StringTransducer.Consume(StringAutomaton.Constant(1.0)));
return(StringDistribution.FromWeightFunction(transducer.ProjectSource(str.ToAutomaton())));
}
/// <summary>
/// Creates an automaton for validating the correctness of argument placeholders for a given argument.
/// </summary>
/// <param name="argToValidateIndex">The index of the argument to validate.</param>
/// <param name="argNames">The names of all arguments.</param>
/// <returns>The created automaton.</returns>
private static StringAutomaton GetArgumentValidatingAutomaton(int argToValidateIndex, IReadOnlyList <string> argNames)
{
Debug.Assert(
argNames != null && argNames.All(name => !string.IsNullOrEmpty(name)),
"A valid array of argument names must be provided.");
Debug.Assert(
argToValidateIndex >= 0 && argToValidateIndex < argNames.Count,
"The provided argument index must be a valid index in the argument name array.");
string argListKey = ArgumentListToDictionaryKey(argToValidateIndex, argNames);
StringAutomaton result;
if (ArgsToValidatingAutomaton.TryGetValue(argListKey, out result))
{
return(result);
}
// Accepts placeholder for the current argument
StringAutomaton checkBracesForCurrentArg = StringAutomaton.ConstantOn(1.0, "{" + argNames[argToValidateIndex] + "}");
StringAutomaton checkBracesForOtherArgs = DisallowBracesAutomaton.Clone();
if (argNames.Count > 1)
{
// Skips placeholders for every argument except the current one
StringAutomaton skipOtherArgs = StringAutomaton.ConstantOnElement(1.0, '{');
skipOtherArgs.AppendInPlace(StringAutomaton.ConstantOn(1.0, argNames.Where((arg, index) => index != argToValidateIndex)));
skipOtherArgs.AppendInPlace(StringAutomaton.ConstantOnElement(1.0, '}'));
// Accepts placeholders for arguments other than current, with arbitrary intermediate text
checkBracesForOtherArgs.AppendInPlace(skipOtherArgs);
checkBracesForOtherArgs = StringAutomaton.Repeat(checkBracesForOtherArgs, minTimes: 0);
checkBracesForOtherArgs.AppendInPlace(DisallowBracesAutomaton);
}
// Checks the placeholder for the current argument, then skips placeholders for other arguments
StringAutomaton validateArgumentThenOtherArguments = checkBracesForCurrentArg.Clone();
validateArgumentThenOtherArguments.AppendInPlace(checkBracesForOtherArgs);
if (!RequirePlaceholderForEveryArgument)
{
// Make this block optional
validateArgumentThenOtherArguments = StringAutomaton.Sum(
validateArgumentThenOtherArguments,
StringAutomaton.ConstantOn(1.0, string.Empty));
}
// Accepts placeholders for arguments other then current, then for the current argument, then again other placeholders
result = checkBracesForOtherArgs.Clone();
result.AppendInPlace(validateArgumentThenOtherArguments);
result.TryDeterminize();
ArgsToValidatingAutomaton[argListKey] = result;
return(result);
}
/// <summary>EP message to <c>str</c>.</summary>
/// <param name="sub">Incoming message from <c>sub</c>.</param>
/// <param name="start">Constant value for <c>start</c>.</param>
/// <param name="length">Constant value for <c>length</c>.</param>
/// <returns>The outgoing EP message to the <c>str</c> argument.</returns>
/// <remarks>
/// <para>The outgoing message is a distribution matching the moments of <c>str</c> as the random arguments are varied. The formula is <c>proj[p(str) sum_(sub) p(sub) factor(sub,str,start,length)]/p(str)</c>.</para>
/// </remarks>
public static StringDistribution StrAverageConditional(StringDistribution sub, int start, int length)
{
Argument.CheckIfNotNull(sub, "sub");
Argument.CheckIfInRange(start >= 0, "start", "Start index must be non-negative.");
Argument.CheckIfInRange(length >= 0, "length", "Length must be non-negative.");
var anyChar = StringAutomaton.ConstantOnElement(1.0, DiscreteChar.Any());
var transducer = StringTransducer.Produce(StringAutomaton.Repeat(anyChar, minTimes: start, maxTimes: start));
transducer.AppendInPlace(StringTransducer.Copy(StringAutomaton.Repeat(anyChar, minTimes: length, maxTimes: length)));
transducer.AppendInPlace(StringTransducer.Produce(StringAutomaton.Constant(1.0)));
return(StringDistribution.FromWorkspace(transducer.ProjectSource(sub)));
}
public void ConsumeAutomaton()
{
StringAutomaton automaton = StringAutomaton.Constant(2.0, DiscreteChar.Lower());
automaton = automaton.Sum(StringAutomaton.ConstantOnElement(3.0, 'a'));
StringTransducer consume = StringTransducer.Consume(automaton);
StringInferenceTestUtilities.TestTransducerValue(consume, "aaa", string.Empty, 2.0);
StringInferenceTestUtilities.TestTransducerValue(consume, "bb", string.Empty, 2.0);
StringInferenceTestUtilities.TestTransducerValue(consume, "a", string.Empty, 5.0);
StringInferenceTestUtilities.TestTransducerValue(consume, string.Empty, string.Empty, 2.0);
StringInferenceTestUtilities.TestTransducerValue(consume, "bb", "aaa", 0.0);
StringInferenceTestUtilities.TestTransducerValue(consume, "bb", "bb", 0.0);
StringInferenceTestUtilities.TestTransducerValue(consume, string.Empty, "bb", 0.0);
StringInferenceTestUtilities.TestTransducerValue(consume, string.Empty, "a", 0.0);
}
public void ProduceAutomaton()
{
StringAutomaton automaton = StringAutomaton.Constant(2.0, ImmutableDiscreteChar.Lower());
automaton = automaton.Sum(StringAutomaton.ConstantOnElement(3.0, 'a'));
StringTransducer produce = StringTransducer.Produce(automaton);
StringInferenceTestUtilities.TestTransducerValue(produce, string.Empty, "aaa", 2.0);
StringInferenceTestUtilities.TestTransducerValue(produce, string.Empty, "bb", 2.0);
StringInferenceTestUtilities.TestTransducerValue(produce, string.Empty, "a", 5.0);
StringInferenceTestUtilities.TestTransducerValue(produce, string.Empty, string.Empty, 2.0);
StringInferenceTestUtilities.TestTransducerValue(produce, "aaa", "bb", 0.0);
StringInferenceTestUtilities.TestTransducerValue(produce, "bb", "bb", 0.0);
StringInferenceTestUtilities.TestTransducerValue(produce, "bb", string.Empty, 0.0);
StringInferenceTestUtilities.TestTransducerValue(produce, "a", string.Empty, 0.0);
}
public void ReplaceAutomaton()
{
StringAutomaton automaton1 = StringAutomaton.Constant(2.0, DiscreteChar.Lower());
automaton1 = automaton1.Sum(StringAutomaton.ConstantOnElement(3.0, 'a'));
StringAutomaton automaton2 = StringAutomaton.Constant(0.5, DiscreteChar.Digit());
automaton2 = automaton2.Sum(StringAutomaton.Constant(2.5, DiscreteChar.LetterOrDigit()));
StringTransducer replace = StringTransducer.Replace(automaton1, automaton2);
StringInferenceTestUtilities.TestTransducerValue(replace, string.Empty, "123", 6.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "a", "123", 15.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "ax", "AbC", 5.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "a", "a", 12.5);
StringInferenceTestUtilities.TestTransducerValue(replace, string.Empty, string.Empty, 6.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "123", string.Empty, 0.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "AbC", "ax", 0.0);
StringInferenceTestUtilities.TestTransducerValue(replace, "1", "1", 0.0);
}