Implements binding and evaluating function declarations

src/Binder/Binder.cpp

@@ -24,6 +24,7 @@ BoundStatement* Binder::BindStatement(ParsedStatement* statement){
         case ParsedStatementKind ::Block: return this -> BindBlockStatement(statement);
         case ParsedStatementKind ::Expression: return this -> BindExpressionStatement(statement);
         case ParsedStatementKind::Assignment: return this -> BindAssignmentStatement(statement);
+        case ParsedStatementKind ::FunctionDeclaration: return this->BindFunctionDeclarationStatement(statement);
 
         case ParsedStatementKind::Bad: return new BoundBadStatement();
     }
@@ -62,6 +63,41 @@ BoundStatement* Binder::BindAssignmentStatement(ParsedStatement *statement){
     }
 }
 
+ScriptType* ParseTypeIdentifier(HashedString s){
+    switch (s.GetHash()){
+        case HashedString::ConstHash("number"): return new NumericScriptType(false, false);
+        case HashedString::ConstHash("bool"): return new ScriptType(TypeClass::Bool);
+        case HashedString::ConstHash("string"): return new ScriptType(TypeClass::String);
+        default: return new ScriptType(TypeClass::Error); // todo: change to userdata
+    }
+}
+
+BoundStatement *Binder::BindFunctionDeclarationStatement(ParsedStatement *statement) {
+    auto functionStatement = (ParsedFunctionDeclarationStatement*) statement;
+    auto parameters = functionStatement->GetParameters();
+    vector<ScriptType*> parameterTypes = vector<ScriptType*>(parameters.size());
+    vector<int> parameterKeys = vector<int>(parameters.size());
+    this->_scope->GoInnerScope();
+    auto scopeId = this->_scope->GetCurrentScope();
+    for (int i = 0; i < parameters.size(); i++){
+        auto var = parameters[i];
+        auto parsedType = ParseTypeIdentifier(var->GetType());
+        parameterTypes[i] = parsedType;
+        parameterKeys[i] = var->GetIdentifier().GetHash();
+        this->_scope->CreateExplicitLocal(var->GetIdentifier().GetHash(), *parsedType);
+    }
+    auto boundBlock = this -> BindBlockStatement(functionStatement->GetBlock());
+    this->_scope->GoOuterScope();
+    auto identifier = functionStatement->GetIdentifier();
+    auto returnType = new ScriptType(TypeClass::Nil);
+    auto type = new FunctionScriptType(returnType, parameterTypes, parameterKeys, scopeId);
+    auto assignment = this->_scope->AssignVariable(identifier.GetHash(), *type);
+    if (assignment.GetResult() == VariableAssignmentResult::Ok){
+        return new BoundFunctionDeclarationStatement(type, assignment.GetKey(), (BoundBlockStatement*)boundBlock);
+    }
+    return new BoundBadStatement();
+}
+
 BoundExpression* Binder::BindExpression(ParsedExpression* expression){
     switch (expression -> GetKind()){
         case ParsedExpressionKind ::LiteralInteger:
@@ -226,3 +262,4 @@ BoundExpression* Binder::BindUnaryOperator(UnaryExpression* expression){
 
 }
 
+

src/Binder/Binder.hpp

@@ -17,6 +17,7 @@ class Binder {
     BoundStatement *BindBlockStatement(ParsedStatement *statement);
     BoundStatement *BindExpressionStatement(ParsedStatement *statement);
     BoundStatement *BindAssignmentStatement(ParsedStatement *statement);
+    BoundStatement *BindFunctionDeclarationStatement(ParsedStatement * statement);
 
     BoundExpression *BindExpression(ParsedExpression *expression);
     BoundExpression *BindVariableExpression(VariableExpression *expression);

src/Binder/BoundStatements/BoundStatement.hpp

@@ -16,6 +16,7 @@ enum class BoundStatementKind{
     Block,
     Expression,
     Assignment,
+    FunctionDeclaration,
 };
 
 class BoundStatement{
@@ -114,4 +115,32 @@ public:
     }
 };
 
+class BoundFunctionDeclarationStatement : public BoundStatement{
+    BoundVariableKey* _key;
+    BoundBlockStatement* _block;
+    FunctionScriptType* _type;
+public:
+    BoundFunctionDeclarationStatement(FunctionScriptType* type, BoundVariableKey* key, BoundBlockStatement* block){
+        _key = key;
+        _block = block;
+        _type = type;
+    }
+
+    BoundStatementKind GetKind() final{
+        return BoundStatementKind ::FunctionDeclaration;
+    }
+
+    BoundVariableKey* GetKey(){
+        return _key;
+    }
+
+    BoundBlockStatement* GetBlock(){
+        return _block;
+    }
+
+    FunctionScriptType* GetType(){
+        return _type;
+    }
+};
+
 #endif //PORYGONLANG_BOUNDSTATEMENT_HPP

src/Binder/BoundVariables/BoundScope.hpp

@@ -32,6 +32,10 @@ public:
     int GetDeepestScope(){
         return _deepestScope;
     }
+
+    int GetCurrentScope(){
+        return _currentScope;
+    }
 };
 
 

src/Evaluator/EvalValues/ScriptFunctionEvalValue.hpp

@@ -0,0 +1,57 @@
+
+#ifndef PORYGONLANG_SCRIPTFUNCTIONEVALVALUE_HPP
+#define PORYGONLANG_SCRIPTFUNCTIONEVALVALUE_HPP
+
+#include "../../ScriptType.hpp"
+#include "EvalValue.hpp"
+#include "../../Binder/BoundStatements/BoundStatement.hpp"
+#include "../Evaluator.hpp"
+
+class ScriptFunctionEvalValue : public EvalValue{
+    BoundBlockStatement* _innerBlock;
+    FunctionScriptType _type;
+public:
+    explicit ScriptFunctionEvalValue(BoundBlockStatement* innerBlock, const FunctionScriptType& type)
+    : _type(type)
+    {
+        _innerBlock = innerBlock;
+    }
+
+    EvalValue* Clone() final{
+        return new ScriptFunctionEvalValue(_innerBlock, _type);
+    }
+
+    ~ScriptFunctionEvalValue() final{
+        delete _innerBlock;
+    }
+
+    ScriptType* GetType() final{
+        return &_type;
+    };
+
+    bool operator ==(EvalValue* b) final{
+        if (b->GetType()->GetClass() != TypeClass::Function)
+            return false;
+        return this->_innerBlock == ((ScriptFunctionEvalValue*)b)->_innerBlock;
+    };
+
+    EvalValue* EvaluateFunction(Evaluator* evaluator, const vector<EvalValue*>& parameters){
+        auto parameterTypes = _type.GetParameterTypes();
+        auto parameterKeys = _type.GetParameterKeys();
+        auto scope = evaluator->GetScope();
+        for (int i = 0; i < parameterTypes.size() && i < parameterKeys.size() && i < parameters.size(); i++){
+            auto parameter = parameters[i];
+            auto requiredType = parameterTypes[i];
+            if (parameter->GetType() != requiredType){
+                throw EvaluationException("Passed wrong type to function.");
+            }
+            auto key = parameterKeys[i];
+            scope->CreateVariable(_type.GetScopeId(), key, parameter->Clone());
+        }
+        evaluator->EvaluateBlockStatement(_innerBlock);
+        return nullptr;
+    }
+};
+
+
+#endif //PORYGONLANG_SCRIPTFUNCTIONEVALVALUE_HPP

src/Evaluator/Evaluator.cpp

@@ -3,6 +3,7 @@
 #include "EvaluationException.hpp"
 #include "../Script.hpp"
 #include "EvaluationScope/EvaluationScope.hpp"
+#include "EvalValues/ScriptFunctionEvalValue.hpp"
 
 void Evaluator::Evaluate(BoundScriptStatement *statement) {
     this->_evaluationScope = new EvaluationScope(this->_scriptData->_scriptVariables, statement->GetDeepestScope());
@@ -15,6 +16,7 @@ void Evaluator::EvaluateStatement(BoundStatement *statement) {
         case BoundStatementKind ::Block: return this -> EvaluateBlockStatement((BoundBlockStatement*)statement);
         case BoundStatementKind ::Expression: return this -> EvaluateExpressionStatement((BoundExpressionStatement*)statement);
         case BoundStatementKind ::Assignment: return this -> EvaluateAssignmentStatement((BoundAssignmentStatement*)statement);
+        case BoundStatementKind ::FunctionDeclaration: return this->EvaluateFunctionDeclarationStatement((BoundFunctionDeclarationStatement*)statement);
 
         case BoundStatementKind::Bad:
             throw;
@@ -46,6 +48,18 @@ void Evaluator::EvaluateAssignmentStatement(BoundAssignmentStatement *statement)
     }
 }
 
+void Evaluator::EvaluateFunctionDeclarationStatement(BoundFunctionDeclarationStatement *statement) {
+    auto type = statement->GetType();
+    auto key = statement->GetKey();
+    auto block = statement->GetBlock();
+    auto value = new ScriptFunctionEvalValue(block, *type);
+    if (key->IsCreation()){
+        this->_evaluationScope->CreateVariable(key->GetScopeId(), key->GetIdentifier(), value);
+    } else{
+        this->_evaluationScope->SetVariable(key->GetScopeId(), key->GetIdentifier(), value);
+    }
+}
+
 EvalValue *Evaluator::EvaluateExpression(BoundExpression *expression) {
     auto type = expression -> GetType();
     switch (type->GetClass()){

src/Evaluator/Evaluator.hpp

@@ -20,9 +20,9 @@ class Evaluator {
     EvaluationScope* _evaluationScope;
 
     void EvaluateStatement(BoundStatement* statement);
-    void EvaluateBlockStatement(BoundBlockStatement* statement);
     void EvaluateExpressionStatement(BoundExpressionStatement* statement);
     void EvaluateAssignmentStatement(BoundAssignmentStatement* statement);
+    void EvaluateFunctionDeclarationStatement(BoundFunctionDeclarationStatement *statement);
 
     EvalValue* EvaluateExpression(BoundExpression* expression);
     NumericEvalValue* EvaluateIntegerExpression(BoundExpression* expression);
@@ -50,7 +50,11 @@ public:
     }
 
     void Evaluate(BoundScriptStatement* statement);
+    void EvaluateBlockStatement(BoundBlockStatement* statement);
 
+    EvaluationScope* GetScope(){
+        return _evaluationScope;
+    }
 };
 
 

src/Evaluator/UnaryEvaluation.cpp

@@ -37,3 +37,4 @@ BooleanEvalValue *Evaluator::EvaluateBooleanUnary(BoundUnaryExpression *expressi
             throw;
     }
 }
+

src/ScriptType.hpp

@@ -1,7 +1,9 @@
-
 #ifndef PORYGONLANG_SCRIPTTYPE_HPP
 #define PORYGONLANG_SCRIPTTYPE_HPP
 
+#include <utility>
+#include <vector>
+
 enum class TypeClass{
     Error,
     Nil,
@@ -55,4 +57,41 @@ public:
     }
 };
 
+class FunctionScriptType : public ScriptType{
+    ScriptType* _returnType;
+    std::vector<ScriptType*> _parameterTypes;
+    std::vector<int> _parameterKeys;
+    int _scopeId;
+public:
+    FunctionScriptType(ScriptType* returnType, std::vector<ScriptType*> parameterTypes, std::vector<int> parameterKeys, int scopeId)
+    : ScriptType(TypeClass::Function){
+        _returnType = returnType;
+        _parameterTypes = std::move(parameterTypes);
+        _parameterKeys = std::move(parameterKeys);
+        _scopeId = scopeId;
+    }
+    ~FunctionScriptType() final{
+        delete _returnType;
+        for (auto t: _parameterTypes){
+            delete t;
+        }
+    }
+
+    ScriptType* GetReturnType(){
+        return _returnType;
+    }
+
+    std::vector<ScriptType*> GetParameterTypes(){
+        return _parameterTypes;
+    }
+
+    std::vector<int> GetParameterKeys(){
+        return _parameterKeys;
+    }
+
+    int GetScopeId(){
+        return _scopeId;
+    }
+};
+
 #endif //PORYGONLANG_SCRIPTTYPE_HPP

src/Utilities/HashedString.hpp

@@ -5,15 +5,17 @@
 #include <string>
 
 class HashedString{
-    int _hash;
+    const int _hash;
-    static unsigned constexpr const_hash(char const *input) {
-        return *input ?
-               static_cast<unsigned int>(*input) + 33 * const_hash(input + 1) :
-               5381;
-    }
 public:
-    explicit HashedString(std::string s){
+    explicit HashedString(const std::string& s) : _hash(ConstHash(s.c_str())){
-        _hash = const_hash(s.c_str());
+    }
+    explicit HashedString(char const *input) : _hash(ConstHash(input)){
+    }
+
+    static unsigned constexpr ConstHash(char const *input) {
+        return *input ?
+               static_cast<unsigned int>(*input) + 33 * ConstHash(input + 1) :
+               5381;
     }
 
     const int GetHash(){

tests/integration/Functions.cpp

@@ -0,0 +1,17 @@
+#ifdef TESTS_BUILD
+#include <catch.hpp>
+#include "../src/Script.hpp"
+
+TEST_CASE( "Define script function", "[integration]" ) {
+    Script* script = Script::Create("function add(number a, number b) a + b end");
+    REQUIRE(!script->Diagnostics -> HasErrors());
+    script->Evaluate();
+    auto variable = script->GetVariable("add");
+    REQUIRE(variable != nullptr);
+    REQUIRE(variable->GetType()->GetClass() == TypeClass::Function);
+    delete script;
+}
+
+
+
+#endif