/// <summary>
/// Creates an <see cref="InterpreterScope"/> with all variables required for the function call.
/// </summary>
public InterpreterScope CreateCaptureScope(InterpreterScope scope)
{
var captureScope = new InterpreterScope(scope);
captureScope.Context = this;
// only have to capture variables for anonymous functions
var userFunctionDefinition = this as AnonymousUserFunctionDefinitionExpression;
if (userFunctionDefinition != null)
{
foreach (var captured in userFunctionDefinition.CapturedVariables)
{
captureScope.DefineVariable(captured.Variable, captured.Expression);
}
}
// set the context to the function definition and return the new context
return(captureScope);
}
/// <summary>
/// Gets the string parameter from the <paramref name="scope"/> or <see cref="DefaultParameters"/> collections.
/// </summary>
/// <param name="scope">The scope.</param>
/// <param name="name">The name of the parameter.</param>
/// <param name="parseError">[out] The error that occurred.</param>
/// <returns>The parameter value, or <c>null</c> if an error occurred.</b></returns>
protected StringConstantExpression GetStringParameter(InterpreterScope scope, string name, out ExpressionBase parseError)
{
var parameter = GetParameter(scope, name, out parseError);
if (parameter == null)
{
return(null);
}
var typedParameter = parameter as StringConstantExpression;
if (typedParameter == null)
{
parseError = new ParseErrorExpression(name + " is not a string", parameter);
return(null);
}
parseError = null;
return(typedParameter);
}
/// <summary>
/// Gets a parameter from the <paramref name="scope"/> or <see cref="DefaultParameters"/> collections.
/// </summary>
/// <param name="scope">The scope.</param>
/// <param name="name">The name of the parameter.</param>
/// <param name="parseError">[out] The error that occurred.</param>
/// <returns>The parameter value, or <c>null</c> if an error occurred.</b></returns>
protected ExpressionBase GetParameter(InterpreterScope scope, string name, out ExpressionBase parseError)
{
var parameter = scope.GetVariable(name);
if (parameter == null)
{
parseError = new ParseErrorExpression("No value provided for " + name + " parameter");
return(null);
}
parseError = null;
// if it's a variable reference, return the referenced object.
if (parameter.Type == ExpressionType.VariableReference)
{
return(((VariableReferenceExpression)parameter).Expression);
}
// WARNING: variable references may still exist within a varargs object
return(parameter);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
ExpressionBase value = scope.GetVariable(Name);
if (value == null)
{
var func = scope.GetFunction(Name);
if (func != null)
{
// special wrapper for returning a function as a variable
result = new FunctionReferenceExpression(Name);
result.CopyLocation(this);
return(true);
}
result = new UnknownVariableParseErrorExpression("Unknown variable: " + Name, this);
return(false);
}
return(value.ReplaceVariables(scope, out result));
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
ExpressionBase value = scope.GetVariable(Name);
if (value == null)
{
var func = scope.GetFunction(Name);
if (func != null)
{
result = new ParseErrorExpression("Function used like a variable: " + Name, this);
}
else
{
result = new ParseErrorExpression("Unknown variable: " + Name, this);
}
return(false);
}
return(value.ReplaceVariables(scope, out result));
}
/// <summary>
/// Merges all varaibles/functions from the provided <see cref="InterpreterScope"/> into this <see cref="InterpreterScope"/>.
/// </summary>
/// <param name="source">The <see cref="InterpreterScope"/> to merge variables/functions from.</param>
internal void Merge(InterpreterScope source)
{
if (source._variable.Key != null)
{
DefineVariable(source._variable.Key, source._variable.Value);
}
else if (source._variables != null)
{
foreach (var kvp in source._variables)
{
DefineVariable(kvp.Value.Key, kvp.Value.Value);
}
}
if (source._functions != null)
{
foreach (var kvp in source._functions)
{
AddFunction(kvp.Value);
}
}
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
ExpressionBase left;
if (!Left.ReplaceVariables(scope, out left))
{
result = left;
return(false);
}
ExpressionBase right;
if (!Right.ReplaceVariables(scope, out right))
{
result = right;
return(false);
}
var comparison = new ComparisonExpression(left, Operation, right);
CopyLocation(comparison);
result = comparison;
return(true);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope"/>.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns><c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result"/> will likely be a <see cref="ParseErrorExpression"/>.</returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
if (!Evaluate(scope, out result))
{
return(false);
}
if (result == null)
{
var functionCall = scope.GetContext <FunctionCallExpression>();
if (functionCall != null)
{
result = new ParseErrorExpression(Name.Name + " did not return a value", functionCall.FunctionName);
}
else
{
result = new ParseErrorExpression(Name.Name + " did not return a value");
}
return(false);
}
return(true);
}
private static ExpressionBase GetParameter(InterpreterScope parameterScope, InterpreterScope scope, AssignmentExpression assignment)
{
ExpressionBase value = assignment.Value;
var variable = value as VariableExpression;
if (variable != null)
{
value = scope.GetVariable(variable.Name);
if (value == null)
{
// could not find variable, fallback to VariableExpression.ReplaceVariables generating an error
value = assignment.Value;
}
else
{
// when a parameter is assigned to a variable that is an array or dictionary,
// assume it has already been evaluated and pass it by reference. this is magnitudes
// more performant, and allows the function to modify the data in the container.
if (value.Type == ExpressionType.Dictionary || value.Type == ExpressionType.Array)
{
value = scope.GetVariableReference(variable.Name);
assignment.Value.CopyLocation(value);
return(value);
}
}
}
if (value.IsConstant)
{
// already a basic type, do nothing
}
else if (value.Type == ExpressionType.FunctionDefinition)
{
var anonymousFunction = value as AnonymousUserFunctionDefinitionExpression;
if (anonymousFunction != null)
{
anonymousFunction.CaptureVariables(parameterScope);
}
}
else
{
bool isLogicalUnit = value.IsLogicalUnit;
// not a basic type, evaluate it
var assignmentScope = new InterpreterScope(scope)
{
Context = assignment
};
if (!value.ReplaceVariables(assignmentScope, out value))
{
var error = (ParseErrorExpression)value;
return(new ParseErrorExpression("Invalid value for parameter: " + assignment.Variable.Name, assignment.Value)
{
InnerError = error
});
}
value.IsLogicalUnit = isLogicalUnit;
assignment.Value.CopyLocation(value);
}
return(value);
}
/// <summary>
/// Creates a new scope for calling a function and populates values for parameters passed to the function.
/// </summary>
/// <param name="function">The function defining the parameters to populate.</param>
/// <param name="scope">The outer scope containing the function call.</param>
/// <param name="error">[out] A <see cref="ParseErrorExpression"/> indicating why constructing the new scope failed.</param>
/// <returns>The new scope, <c>null</c> if an error occurred - see <paramref name="error"/> for error details.</returns>
public InterpreterScope GetParameters(FunctionDefinitionExpression function, InterpreterScope scope, out ExpressionBase error)
{
var parameterScope = function.CreateCaptureScope(scope);
// optimization for no parameter function
if (function.Parameters.Count == 0 && Parameters.Count == 0)
{
error = null;
return(parameterScope);
}
// optimization for single parameter function
if (function.Parameters.Count == 1 && Parameters.Count == 1)
{
if (GetSingleParameter(function, parameterScope, out error))
{
return(parameterScope);
}
if (error != null)
{
return(null);
}
}
var providedParameters = new List <string>(function.Parameters.Count);
foreach (var parameter in function.Parameters)
{
providedParameters.Add(parameter.Name);
}
ArrayExpression varargs = null;
if (providedParameters.Remove("..."))
{
varargs = new ArrayExpression();
parameterScope.DefineVariable(new VariableDefinitionExpression("varargs"), varargs);
}
var parameterCount = providedParameters.Count;
int index = 0;
bool namedParameters = false;
foreach (var parameter in Parameters)
{
var assignedParameter = parameter as AssignmentExpression;
if (assignedParameter != null)
{
if (!providedParameters.Remove(assignedParameter.Variable.Name))
{
if (!function.Parameters.Any(p => p.Name == assignedParameter.Variable.Name))
{
error = new ParseErrorExpression(String.Format("'{0}' does not have a '{1}' parameter", function.Name.Name, assignedParameter.Variable.Name), parameter);
return(null);
}
error = new ParseErrorExpression(String.Format("'{0}' already has a value", assignedParameter.Variable.Name), assignedParameter.Variable);
return(null);
}
var value = GetParameter(parameterScope, scope, assignedParameter);
error = value as ParseErrorExpression;
if (error != null)
{
return(null);
}
parameterScope.DefineVariable(new VariableDefinitionExpression(assignedParameter.Variable), value);
namedParameters = true;
}
else
{
if (namedParameters)
{
error = new ParseErrorExpression("Non-named parameter following named parameter", parameter);
return(null);
}
if (index >= parameterCount && varargs == null)
{
error = new ParseErrorExpression("Too many parameters passed to function", parameter);
return(null);
}
var variableName = (index < parameterCount) ? function.Parameters.ElementAt(index).Name : "...";
assignedParameter = new AssignmentExpression(new VariableExpression(variableName), parameter);
var value = GetParameter(parameterScope, scope, assignedParameter);
error = value as ParseErrorExpression;
if (error != null)
{
return(null);
}
if (index < parameterCount)
{
providedParameters.Remove(variableName);
parameterScope.DefineVariable(new VariableDefinitionExpression(variableName), value);
}
else
{
varargs.Entries.Add(value);
}
}
++index;
}
foreach (var parameter in providedParameters)
{
ExpressionBase value;
if (!function.DefaultParameters.TryGetValue(parameter, out value))
{
error = new ParseErrorExpression(String.Format("Required parameter '{0}' not provided", parameter), FunctionName);
return(null);
}
var assignmentScope = new InterpreterScope(scope)
{
Context = new AssignmentExpression(new VariableExpression(parameter), value)
};
if (!value.ReplaceVariables(assignmentScope, out value))
{
error = new ParseErrorExpression(value, this);
return(null);
}
parameterScope.DefineVariable(new VariableDefinitionExpression(parameter), value);
}
error = null;
return(parameterScope);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
if (Entries.Count == 0)
{
result = this;
return(true);
}
var dictScope = new InterpreterScope(scope);
var entries = new List <DictionaryEntry>();
foreach (var entry in Entries)
{
ExpressionBase key, value;
key = entry.Key;
dictScope.Context = new AssignmentExpression(new VariableExpression("@key"), key);
if (key.Type == ExpressionType.FunctionCall)
{
var expression = (FunctionCallExpression)key;
if (!expression.ReplaceVariables(dictScope, out value))
{
result = value;
return(false);
}
key = value;
}
if (!key.ReplaceVariables(dictScope, out key))
{
result = key;
return(false);
}
switch (key.Type)
{
case ExpressionType.StringConstant:
dictScope.Context = new AssignmentExpression(new VariableExpression("[" + ((StringConstantExpression)key).Value + "]"), entry.Value);
break;
case ExpressionType.IntegerConstant:
dictScope.Context = new AssignmentExpression(new VariableExpression("[" + ((IntegerConstantExpression)key).Value.ToString() + "]"), entry.Value);
break;
default:
result = new ParseErrorExpression("Dictionary key must evaluate to a constant", key);
return(false);
}
if (!entry.Value.ReplaceVariables(dictScope, out value))
{
result = value;
return(false);
}
if (entries.Exists(e => e.Key == key))
{
StringBuilder builder = new StringBuilder();
key.AppendString(builder);
builder.Append(" already exists in dictionary");
result = new ParseErrorExpression(builder.ToString(), entry.Key);
return(false);
}
entries.Add(new DictionaryEntry {
Key = key, Value = value
});
}
result = new DictionaryExpression {
Entries = entries
};
return(true);
}
private bool Evaluate(InterpreterScope scope, bool inAssignment, out ExpressionBase result)
{
var functionDefinition = scope.GetFunction(FunctionName.Name);
if (functionDefinition == null)
{
if (scope.GetVariable(FunctionName.Name) != null)
{
result = new UnknownVariableParseErrorExpression(FunctionName.Name + " is not a function", FunctionName);
}
else
{
result = new UnknownVariableParseErrorExpression("Unknown function: " + FunctionName.Name, FunctionName);
}
return(false);
}
var functionParametersScope = GetParameters(functionDefinition, scope, out result);
if (functionParametersScope == null || result is ParseErrorExpression)
{
return(false);
}
if (functionParametersScope.Depth >= 100)
{
result = new ParseErrorExpression("Maximum recursion depth exceeded", this);
return(false);
}
functionParametersScope.Context = this;
if (inAssignment)
{
// in assignment, just replace variables
functionDefinition.ReplaceVariables(functionParametersScope, out result);
if (result.Type == ExpressionType.FunctionCall)
{
// if the result is a function call, check for any variable references. it can't be marked
// as fully expanded if any variable references are present.
var functionCall = (FunctionCallExpression)result;
if (!functionCall.Parameters.Any(p => p is VariableReferenceExpression))
{
functionCall._fullyExpanded = true;
}
// if there was no change, also mark the source as fully expanded.
if (result == this)
{
_fullyExpanded = true;
}
// when expanding the parameters, a new functionCall object will be created without a name
// location. if that has happened, replace the temporary name object with the real one.
if (functionCall.FunctionName.Location.Start.Line == 0 && functionCall.FunctionName.Name == FunctionName.Name)
{
functionCall.FunctionName = FunctionName;
}
}
}
else
{
// not in assignment, evaluate the function
functionDefinition.Evaluate(functionParametersScope, out result);
}
var error = result as ParseErrorExpression;
if (error != null)
{
if (error.Location.Start.Line == 0)
{
this.CopyLocation(error);
}
result = ParseErrorExpression.WrapError(error, FunctionName.Name + " call failed", FunctionName);
return(false);
}
return(true);
}
public InterpreterScope(InterpreterScope parent)
: this()
{
_parent = parent;
Depth = parent.Depth + 1;
}
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
return(Expression.ReplaceVariables(scope, out result));
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
ExpressionBase left;
if (!Left.ReplaceVariables(scope, out left))
{
result = left;
return(false);
}
ExpressionBase right;
if (!Right.ReplaceVariables(scope, out right))
{
result = right;
return(false);
}
var integerLeft = left as IntegerConstantExpression;
var integerRight = right as IntegerConstantExpression;
switch (Operation)
{
case MathematicOperation.Add:
var stringLeft = left as StringConstantExpression;
var stringRight = right as StringConstantExpression;
if (stringLeft != null)
{
if (stringRight != null)
{
result = new StringConstantExpression(stringLeft.Value + stringRight.Value);
return(true);
}
if (integerRight != null)
{
result = new StringConstantExpression(stringLeft.Value + integerRight.Value.ToString());
return(true);
}
}
else if (stringRight != null)
{
if (integerLeft != null)
{
result = new StringConstantExpression(integerLeft.Value.ToString() + stringRight.Value);
return(true);
}
}
// prefer constants on right
if (integerLeft != null && integerRight == null)
{
var temp = left;
left = right;
right = temp;
integerRight = integerLeft;
integerLeft = null;
}
if (integerRight != null)
{
if (integerRight.Value == 0) // anything plus 0 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value + integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Subtract:
if (integerRight != null)
{
if (integerRight.Value == 0) // anything minus 0 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value - integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Multiply:
// prefer constants on right
if (integerLeft != null && integerRight == null)
{
var temp = left;
left = right;
right = temp;
integerRight = integerLeft;
integerLeft = null;
}
if (integerRight != null)
{
if (integerRight.Value == 0) // anything times 0 is 0
{
result = right;
return(true);
}
if (integerRight.Value == 1) // anything times 1 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value * integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Divide:
if (integerRight != null)
{
if (integerRight.Value == 0) // division by 0 is impossible
{
result = new ParseErrorExpression("division by zero", this);
return(false);
}
if (integerRight.Value == 1) // anything divided by 1 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value / integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Modulus:
if (integerRight != null)
{
if (integerRight.Value == 0) // division by 0 is impossible
{
result = new ParseErrorExpression("division by zero", this);
return(false);
}
if (integerRight.Value == 1) // anything modulus 1 is 0
{
result = new IntegerConstantExpression(0);
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value % integerRight.Value);
return(true);
}
}
break;
}
var mathematic = new MathematicExpression(left, Operation, right);
mathematic.Line = Line;
mathematic.Column = Column;
result = mathematic;
return(true);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope"/>.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns><c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result"/> will likely be a <see cref="ParseErrorExpression"/>.</returns>
public virtual bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
result = this;
return(true);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
if (_fullyExpanded)
{
result = this;
return(true);
}
bool hasTrue = false;
bool hasFalse = false;
bool isChanged = false;
var updatedConditions = new List <ExpressionBase>(_conditions.Count);
for (int i = 0; i < _conditions.Count; ++i)
{
if (!_conditions[i].ReplaceVariables(scope, out result))
{
return(false);
}
// can eliminate true/false now, but not things that evaluate to true/false.
// (like always_true or always_false) as those may be used to generate explicit alt groups.
var booleanExpression = result as BooleanConstantExpression;
if (booleanExpression != null)
{
if (booleanExpression.Value)
{
hasTrue = true;
if (Operation == ConditionalOperation.And)
{
isChanged = true;
continue;
}
}
else
{
hasFalse = true;
if (Operation == ConditionalOperation.Or)
{
isChanged = true;
continue;
}
}
}
isChanged |= !ReferenceEquals(result, _conditions[i]);
updatedConditions.Add(result);
}
bool?logicalResult = null;
switch (Operation)
{
case ConditionalOperation.Not:
if (hasTrue)
{
logicalResult = false;
}
else if (hasFalse)
{
logicalResult = true;
}
else
{
result = InvertExpression(updatedConditions[0]);
if (result.Type == ExpressionType.ParseError)
{
return(false);
}
CopyLocation(result);
// InvertExpression may distribute Nots to subnodes, recurse
return(result.ReplaceVariables(scope, out result));
}
break;
case ConditionalOperation.Or:
if (hasTrue)
{
// anything or true is true
logicalResult = true;
}
else if (hasFalse && updatedConditions.Count == 0)
{
// all conditions were false, entire condition is false
logicalResult = false;
}
break;
case ConditionalOperation.And:
if (hasFalse)
{
// anything and false is false
logicalResult = false;
}
if (hasTrue && updatedConditions.Count == 0)
{
// all conditions were true, entire condition is true
logicalResult = true;
}
break;
}
if (logicalResult == true)
{
result = new BooleanConstantExpression(true);
}
else if (logicalResult == false)
{
result = new BooleanConstantExpression(false);
}
else
{
// merge with nested logic when possible
for (int i = updatedConditions.Count - 1; i >= 0; i--)
{
var conditionalExpression = updatedConditions[i] as ConditionalExpression;
if (conditionalExpression != null && conditionalExpression.Operation == Operation)
{
updatedConditions.RemoveAt(i);
updatedConditions.InsertRange(i, conditionalExpression._conditions);
isChanged = true;
}
}
if (!isChanged)
{
_fullyExpanded = true;
result = this;
return(true);
}
else
{
var newConditionalExpression = new ConditionalExpression(Operation, updatedConditions);
newConditionalExpression._fullyExpanded = true;
result = newConditionalExpression;
}
}
CopyLocation(result);
return(true);
}
/// <summary>
/// Determines whether the expression evaluates to true for the provided <paramref name="scope" />
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="error">[out] The error that prevented evaluation (or null if successful).</param>
/// <returns>
/// The result of evaluating the expression
/// </returns>
public override bool?IsTrue(InterpreterScope scope, out ParseErrorExpression error)
{
bool?isTrue;
switch (Operation)
{
case ConditionalOperation.And:
foreach (var condition in _conditions)
{
isTrue = condition.IsTrue(scope, out error);
if (error != null)
{
return(isTrue);
}
if (isTrue == false)
{
return(false);
}
if (isTrue == null)
{
return(null);
}
}
error = null;
return(true);
case ConditionalOperation.Or:
foreach (var condition in _conditions)
{
isTrue = condition.IsTrue(scope, out error);
if (error != null)
{
return(isTrue);
}
if (isTrue == true)
{
return(true);
}
if (isTrue == null)
{
return(null);
}
}
error = null;
return(false);
case ConditionalOperation.Not:
isTrue = _conditions[0].IsTrue(scope, out error);
if (isTrue == null)
{
return(null);
}
return(!isTrue);
default:
error = null;
return(null);
}
}
protected new ExpressionBase Parse(PositionalTokenizer tokenizer)
{
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != '(')
{
return(ExpressionBase.ParseError(tokenizer, "Expected '(' after function name", Name));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ')')
{
do
{
var line = tokenizer.Line;
var column = tokenizer.Column;
var parameter = tokenizer.ReadIdentifier();
if (parameter.IsEmpty)
{
return(ExpressionBase.ParseError(tokenizer, "Invalid parameter name", line, column));
}
var variableDefinition = new VariableDefinitionExpression(parameter.ToString(), line, column);
Parameters.Add(variableDefinition);
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar == '=')
{
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
var value = ExpressionBase.Parse(tokenizer);
if (value.Type == ExpressionType.ParseError)
{
return(ExpressionBase.ParseError(tokenizer, "Invalid default value for " + parameter.ToString(), value));
}
var scope = new InterpreterScope(AchievementScriptInterpreter.GetGlobalScope());
scope.Context = new TriggerBuilderContext(); // prevent errors passing memory references as default parameters
ExpressionBase evaluated;
if (!value.ReplaceVariables(scope, out evaluated))
{
return(ExpressionBase.ParseError(tokenizer, "Default value for " + parameter.ToString() + " is not constant", evaluated));
}
DefaultParameters[parameter.ToString()] = evaluated;
}
else if (DefaultParameters.Count > 0)
{
return(ExpressionBase.ParseError(tokenizer,
string.Format("Non-default parameter {0} appears after default parameters", parameter.ToString()), variableDefinition));
}
if (tokenizer.NextChar == ')')
{
break;
}
if (tokenizer.NextChar != ',')
{
return(ExpressionBase.ParseError(tokenizer, "Expected ',' or ')' after parameter name, found: " + tokenizer.NextChar));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
} while (true);
}
tokenizer.Advance(); // closing parenthesis
ExpressionBase.SkipWhitespace(tokenizer);
ExpressionBase expression;
if (tokenizer.Match("=>"))
{
return(ParseShorthandBody(tokenizer));
}
if (tokenizer.NextChar != '{')
{
return(ExpressionBase.ParseError(tokenizer, "Expected '{' after function declaration", Name));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
bool seenReturn = false;
while (tokenizer.NextChar != '}')
{
expression = ExpressionBase.Parse(tokenizer);
if (expression.Type == ExpressionType.ParseError)
{
// the ExpressionTokenizer will capture the error, we should still return the incomplete FunctionDefinition
if (tokenizer is ExpressionTokenizer)
{
break;
}
// not an ExpressionTokenizer, just return the error
return(expression);
}
if (expression.Type == ExpressionType.Return)
{
seenReturn = true;
}
else if (seenReturn)
{
ExpressionBase.ParseError(tokenizer, "Expression after return statement", expression);
}
Expressions.Add(expression);
ExpressionBase.SkipWhitespace(tokenizer);
}
Location = new TextRange(Location.Start, tokenizer.Location);
tokenizer.Advance();
return(MakeReadOnly(this));
}
internal DictionaryExpression.DictionaryEntry GetDictionaryEntry(InterpreterScope scope, out ExpressionBase result, bool create)
{
ExpressionBase index;
if (Index.Type == ExpressionType.FunctionCall)
{
var expression = (FunctionCallExpression)Index;
if (!expression.ReplaceVariables(scope, out index))
{
result = index;
return(null);
}
}
else if (!Index.ReplaceVariables(scope, out index))
{
result = index;
return(null);
}
ExpressionBase value;
var indexed = Variable as IndexedVariableExpression;
if (indexed != null)
{
var entry = indexed.GetDictionaryEntry(scope, out result, create);
if (entry == null)
{
return(null);
}
value = entry.Value;
}
else
{
var variable = Variable as VariableExpression;
if (variable != null)
{
value = scope.GetVariable(variable.Name);
if (value == null)
{
result = new ParseErrorExpression("Unknown variable: " + variable.Name, variable);
return(null);
}
}
else if (!Variable.ReplaceVariables(scope, out value))
{
result = value;
return(null);
}
}
var dict = value as DictionaryExpression;
if (dict != null)
{
var entry = dict.Entries.FirstOrDefault(e => Object.Equals(e.Key, index));
if (entry != null)
{
result = dict;
return(entry);
}
if (create)
{
entry = new DictionaryExpression.DictionaryEntry {
Key = index
};
dict.Entries.Add(entry);
result = dict;
return(entry);
}
var builder = new StringBuilder();
builder.Append("No entry in dictionary for key: ");
index.AppendString(builder);
result = new ParseErrorExpression(builder.ToString(), Index);
}
else
{
var array = value as ArrayExpression;
if (array != null)
{
var intIndex = index as IntegerConstantExpression;
if (intIndex == null)
{
result = new ParseErrorExpression("Index does not evaluate to an integer constant", index);
}
else if (intIndex.Value < 0 || intIndex.Value >= array.Entries.Count)
{
result = new ParseErrorExpression(String.Format("Index {0} not in range 0-{1}", intIndex.Value, array.Entries.Count - 1), index);
}
else
{
result = array;
return(new ArrayDictionaryEntryWrapper {
Array = array, Key = index, Value = array.Entries[intIndex.Value]
});
}
}
else
{
var builder = new StringBuilder();
builder.Append("Cannot index: ");
Variable.AppendString(builder);
builder.Append(" (");
builder.Append(value.Type);
builder.Append(')');
result = new ParseErrorExpression(builder.ToString(), Variable);
}
}
return(null);
}
/// <summary>
/// Determines whether the expression evaluates to true for the provided <paramref name="scope"/>
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="error">[out] The error that prevented evaluation (or null if successful).</param>
/// <returns>The result of evaluating the expression</returns>
public virtual bool?IsTrue(InterpreterScope scope, out ParseErrorExpression error)
{
error = null;
return(null);
}
/// <summary>
/// Determines whether the expression evaluates to true for the provided <paramref name="scope" />
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="error">[out] The error that prevented evaluation (or null if successful).</param>
/// <returns>
/// The result of evaluating the expression
/// </returns>
public override bool IsTrue(InterpreterScope scope, out ParseErrorExpression error)
{
ExpressionBase left, right;
if (!Left.ReplaceVariables(scope, out left))
{
error = left as ParseErrorExpression;
return(false);
}
if (!Right.ReplaceVariables(scope, out right))
{
error = right as ParseErrorExpression;
return(false);
}
error = null;
var integerLeft = left as IntegerConstantExpression;
if (integerLeft != null)
{
var integerRight = right as IntegerConstantExpression;
if (integerRight == null)
{
return(false);
}
switch (Operation)
{
case ComparisonOperation.Equal:
return(integerLeft.Value == integerRight.Value);
case ComparisonOperation.NotEqual:
return(integerLeft.Value != integerRight.Value);
case ComparisonOperation.GreaterThan:
return(integerLeft.Value > integerRight.Value);
case ComparisonOperation.GreaterThanOrEqual:
return(integerLeft.Value >= integerRight.Value);
case ComparisonOperation.LessThan:
return(integerLeft.Value < integerRight.Value);
case ComparisonOperation.LessThanOrEqual:
return(integerLeft.Value <= integerRight.Value);
default:
return(false);
}
}
var stringLeft = left as StringConstantExpression;
if (stringLeft != null)
{
var stringRight = right as StringConstantExpression;
if (stringRight == null)
{
return(false);
}
switch (Operation)
{
case ComparisonOperation.Equal:
return(stringLeft.Value == stringRight.Value);
case ComparisonOperation.NotEqual:
return(stringLeft.Value != stringRight.Value);
case ComparisonOperation.GreaterThan:
return(String.Compare(stringLeft.Value, stringRight.Value) > 0);
case ComparisonOperation.GreaterThanOrEqual:
return(String.Compare(stringLeft.Value, stringRight.Value) >= 0);
case ComparisonOperation.LessThan:
return(String.Compare(stringLeft.Value, stringRight.Value) < 0);
case ComparisonOperation.LessThanOrEqual:
return(String.Compare(stringLeft.Value, stringRight.Value) <= 0);
default:
return(false);
}
}
return(false);
}
public override bool?IsTrue(InterpreterScope scope, out ParseErrorExpression error)
{
error = null;
return(Value);
}
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
result = new StringConstantExpression(Value);
CopyLocation(result);
return(true);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
var newDict = new DictionaryExpression();
var entries = newDict._entries;
if (_state == DictionaryState.Unprocessed)
{
result = UpdateState();
if (result != null)
{
return(false);
}
}
// constant dictionary
if (_state == DictionaryState.ConstantSorted)
{
entries.AddRange(_entries);
result = newDict;
CopyLocation(result);
return(true);
}
// non-constant dictionary - have to evaluate
var dictScope = new InterpreterScope(scope);
foreach (var entry in _entries)
{
ExpressionBase key, value;
key = entry.Key;
if (!key.IsConstant)
{
dictScope.Context = new AssignmentExpression(new VariableExpression("@key"), key);
if (!key.ReplaceVariables(dictScope, out value))
{
result = value;
return(false);
}
if (!value.IsConstant)
{
result = new ParseErrorExpression("Dictionary key must evaluate to a constant", key);
return(false);
}
key = value;
}
if (entry.Value.IsConstant)
{
value = entry.Value;
}
else
{
var builder = new StringBuilder();
builder.Append('[');
key.AppendString(builder);
builder.Append(']');
dictScope.Context = new AssignmentExpression(new VariableExpression(builder.ToString()), entry.Value);
if (!entry.Value.ReplaceVariables(dictScope, out value))
{
result = value;
return(false);
}
}
var newEntry = new DictionaryEntry {
Key = key, Value = value
};
if (_state == DictionaryState.ConstantKeysSorted)
{
entries.Add(newEntry);
}
else
{
var index = entries.BinarySearch(newEntry, newEntry);
if (index >= 0)
{
StringBuilder builder = new StringBuilder();
key.AppendString(builder);
builder.Append(" already exists in dictionary");
result = new ParseErrorExpression(builder.ToString(), entry.Key);
return(false);
}
entries.Insert(~index, newEntry);
}
}
newDict._state = DictionaryState.ConstantSorted;
result = newDict;
CopyLocation(result);
return(true);
}
