public ForEachStatement(
IExecutable declarationStatement,
IValue loopVariable,
IValueGetter containerExpression,
IExecutable loopBody,
KeywordToken keywordToken)
{
if (!typeof(IEnumerable).IsAssignableFrom(containerExpression.GetValueType()))
{
throw new ScriptParsingException(
source: keywordToken,
message: $"Collection of ForEach statement is not an Enumerable collection: {containerExpression.GetValueType().Name}");
}
if (!loopVariable.GetValueType().AssignableFromType(containerExpression.GetValueType().GetGenericArguments()[0]))
{
throw new ScriptParsingException(
source: keywordToken,
message: $"Collection items of type " +
$"({containerExpression.GetValueType().GetGenericArguments()[0].Name}) " +
$"not assignable to declared item type: {loopVariable.GetValueType().Name}");
}
this.loopVariable = loopVariable;
this.declarationStatement = declarationStatement;
this.containerExpression = containerExpression;
this.loopBody = loopBody;
}
public void ValidateFlowControlKeyword(KeywordToken controlKeyword)
{
if (!ControlKeywordValid())
{
throw new ScriptParsingException(
source: controlKeyword,
message: $"Unable to use control keyword {controlKeyword.keyword} here. No Loop present in parent contexts.");
}
}
public void ValidateReturn(KeywordToken returnKeyword, Type returnType)
{
if (!GetReturnType().AssignableFromType(returnType))
{
throw new ScriptParsingException(
source: returnKeyword,
message: $"Unable to return value. Expected type {GetReturnType().Name}, received type {returnType.Name}.");
}
}
public ReturnStatement(
KeywordToken keywordToken,
IValueGetter returnValue,
CompilationContext context)
{
this.returnValue = returnValue;
context.ValidateReturn(
returnKeyword: keywordToken,
returnType: returnValue?.GetValueType() ?? typeof(void));
returnType = context.GetReturnType();
}
public WhileStatement(
IValueGetter continueExpression,
IExecutable loopBody,
KeywordToken keywordToken)
{
if (continueExpression.GetValueType() != typeof(bool))
{
throw new ScriptParsingException(
source: keywordToken,
message: $"ContinueExpression of {keywordToken} statement is not a boolean value: type {continueExpression.GetValueType().Name}");
}
this.continueExpression = continueExpression;
this.loopBody = loopBody;
}
public ControlStatement(
KeywordToken keywordToken,
CompilationContext context)
{
keyword = keywordToken.keyword;
context.ValidateFlowControlKeyword(keywordToken);
switch (keyword)
{
case Keyword.Continue:
case Keyword.Break:
//Acceptable
break;
default: throw new ArgumentException($"Unexpected Keyword: {keyword}");
}
}
public static Type ReadType(this IEnumerator <Token> tokens)
{
KeywordToken typeToken = tokens.GetTokenAndAdvance <KeywordToken>();
if (!typeToken.keyword.IsTypeKeyword())
{
throw new ScriptParsingException(
source: typeToken,
message: $"Expected a Type keyword, but instead found: {typeToken.keyword}");
}
if (typeToken.keyword.IsGenericType())
{
return(typeToken.keyword.GetValueType().MakeGenericType(tokens.ReadTypeArguments()));
}
return(typeToken.keyword.GetValueType());
}
private static IExecutable ParseKeywordStatement(
KeywordToken kwToken,
IEnumerator <Token> tokens,
CompilationContext context)
{
//Valid operations:
// Continue, Break
// Return (With or Without return value)
// Declaration (With or Without assignment, with or without global)
// If ( Condition )
// While ( Condition )
// For ( A; B; C )
bool constDeclaration = false;
switch (kwToken.keyword)
{
case Keyword.If:
{
tokens.CautiousAdvance();
tokens.AssertAndSkip(Separator.OpenParen);
IValueGetter ifTest = Expression.ParseNextGetterExpression(tokens, context);
tokens.AssertAndSkip(Separator.CloseParen);
IExecutable trueStatement = ParseNextStatement(tokens, context);
IExecutable falseStatement = null;
if (trueStatement == null)
{
throw new ScriptParsingException(
source: kwToken,
message: $"No statement returned for If block: {kwToken}");
}
//Check the next token for Else or Else IF
if (tokens.TestAndConditionallySkip(Keyword.Else))
{
falseStatement = ParseNextStatement(tokens, context);
}
else if (tokens.TestWithoutSkipping(Keyword.ElseIf))
{
KeywordToken replacementIf = new KeywordToken(
source: tokens.Current,
keyword: Keyword.If);
falseStatement = ParseKeywordStatement(
kwToken: replacementIf,
tokens: tokens,
context: context);
}
return(new IfStatement(
condition: ifTest,
trueBlock: trueStatement,
falseBlock: falseStatement,
keywordToken: kwToken));
}
case Keyword.While:
{
tokens.CautiousAdvance();
//New context is used for loop
context = context.CreateChildScope(true);
tokens.AssertAndSkip(Separator.OpenParen);
IValueGetter conditionTest = Expression.ParseNextGetterExpression(tokens, context);
tokens.AssertAndSkip(Separator.CloseParen);
IExecutable loopBody = ParseNextStatement(tokens, context);
return(new WhileStatement(
continueExpression: conditionTest,
loopBody: loopBody,
keywordToken: kwToken));
}
case Keyword.For:
{
tokens.CautiousAdvance();
//New context is used for loop
context = context.CreateChildScope(true);
//Open Paren
tokens.AssertAndSkip(Separator.OpenParen);
//Initialization
IExecutable initializationStatement = ParseNextStatement(tokens, context);
//Semicolon already skipped by statement parsing
//Continue Expression
IValueGetter continueExpression = Expression.ParseNextGetterExpression(tokens, context);
//Semicolon
tokens.AssertAndSkip(Separator.Semicolon);
//Increment
IExecutable incrementStatement = ParseForIncrementer(tokens, context);
//Close Paren
tokens.AssertAndSkip(Separator.CloseParen);
IExecutable loopBody = ParseNextStatement(tokens, context);
return(new ForStatement(
initializationStatement: initializationStatement,
continueExpression: continueExpression,
incrementStatement: incrementStatement,
loopBody: loopBody,
keywordToken: kwToken));
}
case Keyword.ForEach:
{
tokens.CautiousAdvance();
//New context is used for loop
context = context.CreateChildScope(true);
//Open Paren
tokens.AssertAndSkip(Separator.OpenParen);
//Item Declaration
Type itemType = tokens.GetTokenAndAdvance <KeywordToken>().keyword.GetValueType();
IdentifierToken identifierToken = tokens.GetTokenAndAdvance <IdentifierToken>();
IExecutable declaration = new DeclarationOperation(
identifierToken: identifierToken,
valueType: itemType,
context: context);
IValue loopVariable = new IdentifierExpression(
identifierToken: identifierToken,
context: context);
tokens.AssertAndSkip(Keyword.In);
//Container
IValueGetter containerExpression = Expression.ParseNextGetterExpression(tokens, context);
//Close Paren
tokens.AssertAndSkip(Separator.CloseParen);
IExecutable loopBody = ParseNextStatement(tokens, context);
return(new ForEachStatement(
declarationStatement: declaration,
loopVariable: loopVariable,
containerExpression: containerExpression,
loopBody: loopBody,
keywordToken: kwToken));
}
case Keyword.Continue:
case Keyword.Break:
{
tokens.CautiousAdvance();
tokens.AssertAndSkip(Separator.Semicolon, false);
return(new ControlStatement(kwToken, context));
}
case Keyword.Return:
{
tokens.CautiousAdvance();
IExecutable returnStatement = new ReturnStatement(
keywordToken: kwToken,
returnValue: Expression.ParseNextGetterExpression(tokens, context),
context: context);
tokens.AssertAndSkip(Separator.Semicolon, false);
return(returnStatement);
}
case Keyword.Extern:
case Keyword.Global:
throw new ScriptParsingException(
source: kwToken,
message: $"{kwToken.keyword} variable declarations invalid in local context. Put them outside classes and methods.");
case Keyword.Const:
constDeclaration = true;
tokens.CautiousAdvance();
goto case Keyword.Bool;
case Keyword.Bool:
case Keyword.Double:
case Keyword.Integer:
case Keyword.String:
case Keyword.List:
case Keyword.Queue:
case Keyword.Stack:
case Keyword.DepletableBag:
case Keyword.DepletableList:
case Keyword.RingBuffer:
case Keyword.Dictionary:
case Keyword.HashSet:
case Keyword.Random:
case Keyword.DataFile:
{
Type valueType = tokens.ReadType();
IdentifierToken identToken = tokens.GetTokenAndAdvance <IdentifierToken>();
if (tokens.TestAndConditionallySkip(Separator.Semicolon, false))
{
if (constDeclaration)
{
throw new ScriptParsingException(
source: kwToken,
message: $"const variable declared without a value. What is the point?");
}
return(new DeclarationOperation(
identifierToken: identToken,
valueType: valueType,
context: context));
}
else if (tokens.TestAndConditionallySkip(Operator.Assignment))
{
IValueGetter initializerExpression = Expression.ParseNextGetterExpression(tokens, context);
tokens.AssertAndSkip(Separator.Semicolon, false);
return(DeclarationAssignmentOperation.CreateDelcaration(
identifierToken: identToken,
valueType: valueType,
initializer: initializerExpression,
isConstant: constDeclaration,
context: context));
}
throw new ScriptParsingException(
source: identToken,
message: $"Invalid variable declaration: {kwToken} {identToken} {tokens.Current}");
}
case Keyword.System:
case Keyword.User:
case Keyword.Debug:
case Keyword.Math:
{
IExecutable identifierStatement =
Expression.ParseNextExecutableExpression(tokens, context);
tokens.AssertAndSkip(Separator.Semicolon, false);
return(identifierStatement);
}
case Keyword.ElseIf:
case Keyword.Else:
throw new ScriptParsingException(
source: kwToken,
message: $"Unpaired {kwToken.keyword} token: {kwToken}");
default:
throw new ScriptParsingException(
source: kwToken,
message: $"A Statement cannot begin with this keyword: {kwToken}");
}
}
private static void HandleNextKeyword(
KeywordToken keywordToken,
List <ParsingUnit> units,
IEnumerator <Token> tokens,
CompilationContext context)
{
switch (keywordToken.keyword)
{
case Keyword.New:
{
tokens.CautiousAdvance();
Type newObjectType = tokens.ReadType();
IValueGetter[] args = ParseArguments(tokens, context);
if (tokens.TestWithoutSkipping(Separator.OpenCurlyBoi))
{
Type itemType = newObjectType.GetInitializerItemType();
if (itemType == null)
{
throw new ScriptParsingException(
source: keywordToken,
message: $"Initializer Lists only function on collections. " +
$"Did you enter the wrong type, or possibly omit a semicolon at the end of the expression?");
}
//Initializer Syntax
IValueGetter[] items = ParseItems(tokens, itemType, context);
units.Add(new ParsedValuedUnit(
value: new ConstructInitializedCollectionExpression(
objectType: newObjectType,
args: args,
items: items,
source: keywordToken),
firstToken: keywordToken));
}
else
{
units.Add(new ParsedValuedUnit(
value: new ConstructObjectExpression(
objectType: newObjectType,
args: args),
firstToken: keywordToken));
}
}
break;
case Keyword.System:
case Keyword.User:
case Keyword.Math:
case Keyword.Debug:
{
tokens.CautiousAdvance();
tokens.AssertAndSkip(Operator.MemberAccess);
IdentifierToken identifierToken = tokens.GetTokenAndAdvance <IdentifierToken>();
if (tokens.TestWithoutSkipping(Operator.IsLessThan))
{
//Generic Method
Type[] internalTypes = tokens.ReadTypeArguments();
units.Add(new ParsedValuedUnit(
value: MemberManagement.HandleStaticGenericMethodExpression(
keywordToken: keywordToken,
args: ParseArguments(tokens, context),
identifier: identifierToken.identifier,
genericTypes: internalTypes),
firstToken: keywordToken));
}
else if (tokens.TestWithoutSkipping(Separator.OpenParen))
{
//Method
units.Add(new ParsedValuedUnit(
value: MemberManagement.HandleStaticMethodExpression(
keywordToken: keywordToken,
args: ParseArguments(tokens, context),
identifier: identifierToken.identifier),
firstToken: keywordToken));
}
else
{
//Member
units.Add(new ParsedValuedUnit(
value: MemberManagement.HandleStaticMemberExpression(
keywordToken: keywordToken,
identifier: identifierToken.identifier),
firstToken: keywordToken));
}
}
break;
default:
units.Add(new TokenUnit(tokens.Current));
tokens.CautiousAdvance();
break;
}
}