/// <summary>
/// Parse Script
/// </summary>
/// <exception cref="ScriptParsingException"></exception>
public Script(
IEnumerator <Token> scriptTokens,
params FunctionSignature[] expectedFunctions)
{
ScriptCompilationContext compilationContext = new ScriptCompilationContext();
while (!(scriptTokens.Current is EOFToken))
{
ParseNextGlobal(scriptTokens, compilationContext);
}
foreach (FunctionSignature data in expectedFunctions)
{
if (!scriptFunctions.ContainsKey(data.identifierToken.identifier))
{
throw new ScriptParsingException(
source: scriptTokens.Current ?? new EOFToken(0, 0),
message: $"Expected Function not found: {data}");
}
if (!data.Matches(scriptFunctions[data.identifierToken.identifier].functionSignature))
{
throw new ScriptParsingException(
source: scriptFunctions[data.identifierToken.identifier].functionSignature.identifierToken,
message: $"Expected Function: {data} Found Function: {scriptFunctions[data.identifierToken.identifier].functionSignature}");
}
}
foreach (ScriptFunction scriptFunction in scriptFunctions.Values)
{
scriptFunction.ParseFunctions(compilationContext);
}
}
public void ParseNextGlobal(
IEnumerator <Token> scriptTokens,
ScriptCompilationContext context)
{
switch (scriptTokens.Current)
{
case KeywordToken kwToken:
//Valid operations:
// Global declaration
// Extern declaration
// Member declaration
// Class declaration
switch (kwToken.keyword)
{
case Keyword.Global:
case Keyword.Extern:
//Parse Global Declaration
{
scriptTokens.CautiousAdvance();
Type valueType = scriptTokens.ReadType();
IdentifierToken identToken = scriptTokens.GetTokenAndAdvance <IdentifierToken>();
IValueGetter initializerExpression = null;
if (scriptTokens.TestAndConditionallySkip(Operator.Assignment))
{
initializerExpression = Expression.ParseNextGetterExpression(scriptTokens, context);
}
scriptTokens.AssertAndSkip(Separator.Semicolon, false);
scriptDeclarations.Add(
new GlobalDeclaration(
identifierToken: identToken,
valueType: valueType,
isExtern: kwToken.keyword == Keyword.Extern,
initializer: initializerExpression,
context: context));
}
return;
case Keyword.Const:
{
scriptTokens.CautiousAdvance();
Type valueType = scriptTokens.ReadType();
IdentifierToken identToken = scriptTokens.GetTokenAndAdvance <IdentifierToken>();
scriptTokens.AssertAndSkip(Operator.Assignment);
IValueGetter initializerExpression = Expression.ParseNextGetterExpression(scriptTokens, context);
scriptTokens.AssertAndSkip(Separator.Semicolon, false);
if (!(initializerExpression is LiteralToken litToken))
{
throw new ScriptParsingException(
source: kwToken,
message: $"The value of Const declarations must be constant");
}
object value = litToken.GetAs <object>();
if (!valueType.IsAssignableFrom(litToken.GetValueType()))
{
value = Convert.ChangeType(value, valueType);
}
context.DeclareConstant(
identifierToken: identToken,
type: valueType,
value: value);
}
return;
case Keyword.Void:
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:
//Parse Function or Member Declaration
{
Type valueType = scriptTokens.ReadType();
IdentifierToken identToken = scriptTokens.GetTokenAndAdvance <IdentifierToken>();
if (scriptTokens.TestWithoutSkipping(Separator.OpenParen))
{
VariableData[] arguments = ParseArgumentsDeclaration(scriptTokens);
if (scriptFunctions.ContainsKey(identToken.identifier))
{
throw new ScriptParsingException(
source: identToken,
message: $"Two declarations of function {identToken.identifier} found.");
}
scriptFunctions.Add(identToken.identifier,
new ScriptFunction(
functionTokens: scriptTokens,
functionSignature: new FunctionSignature(
identifierToken: identToken,
returnType: valueType,
arguments: arguments),
context: context));
}
else
{
//Member declaration
if (kwToken.keyword == Keyword.Void)
{
throw new ScriptParsingException(
source: kwToken,
message: $"Cannot declare a member of type Void");
}
IValueGetter initializerExpression = null;
if (scriptTokens.TestAndConditionallySkip(Operator.Assignment))
{
initializerExpression = Expression.ParseNextGetterExpression(scriptTokens, context);
}
scriptTokens.AssertAndSkip(Separator.Semicolon, false);
scriptDeclarations.Add(
new MemberDeclaration(
identifierToken: identToken,
valueType: valueType,
initializer: initializerExpression,
context: context));
}
}
return;
default:
throw new ScriptParsingException(
source: kwToken,
message: $"Token not valid for global context: {kwToken}.");
}
default:
throw new ScriptParsingException(
source: scriptTokens.Current,
message: $"Token not valid for global context: {scriptTokens.Current}.");
}
}