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Eval: Move logic from defines back into functions

master
Riyyi 2 years ago
parent
commit
21f0d8fbd8
  1. 206
      src/eval.cpp
  2. 3
      src/eval.h

206
src/eval.cpp

@ -27,105 +27,6 @@ Eval::Eval(ASTNodePtr ast, EnvironmentPtr env)
// -----------------------------------------
#define EVAL_LET(ast, nodes, env) \
{ \
if (nodes.size() != 2) { \
Error::the().add(format("wrong number of arguments: let*, {}", nodes.size())); \
return nullptr; \
} \
\
auto first_argument = *nodes.begin(); \
auto second_argument = *std::next(nodes.begin()); \
\
/* First argument needs to be a List or Vector */ \
if (!is<Collection>(first_argument.get())) { \
Error::the().add(format("wrong argument type: collection, '{}'", first_argument)); \
return nullptr; \
} \
\
/* Get the nodes out of the List or Vector */ \
std::list<ASTNodePtr> binding_nodes; \
auto bindings = std::static_pointer_cast<Collection>(first_argument); \
binding_nodes = bindings->nodes(); \
\
/* List or Vector needs to have an even number of elements */ \
size_t count = binding_nodes.size(); \
if (count % 2 != 0) { \
Error::the().add(format("wrong number of arguments: {}, {}", "let* bindings", count)); \
return nullptr; \
} \
\
/* Create new environment */ \
auto let_env = Environment::create(env); \
\
for (auto it = binding_nodes.begin(); it != binding_nodes.end(); std::advance(it, 2)) { \
/* First element needs to be a Symbol */ \
if (!is<Symbol>(*it->get())) { \
Error::the().add(format("wrong argument type: symbol, '{}'", *it)); \
return nullptr; \
} \
\
std::string key = std::static_pointer_cast<Symbol>(*it)->symbol(); \
m_ast_stack.push(*std::next(it)); \
m_env_stack.push(let_env); \
ASTNodePtr value = evalImpl(); \
let_env->set(key, value); \
} \
\
/* TODO: Remove limitation of 3 arguments */ \
/* Eval all values in this new env, return last sexp of the result */ \
m_ast_stack.push(second_argument); \
m_env_stack.push(let_env); \
continue; /* TCO */ \
}
#define EVAL_DO(ast, nodes, env) \
{ \
if (nodes.size() == 0) { \
Error::the().add(format("wrong number of arguments: do, {}", nodes.size())); \
return nullptr; \
} \
\
/* Evaluate all nodes except the last */ \
for (auto it = nodes.begin(); it != std::prev(nodes.end(), 1); ++it) { \
m_ast_stack.push(*it); \
m_env_stack.push(env); \
evalImpl(); \
} \
\
/* Eval last node */ \
m_ast_stack.push(nodes.back()); \
m_env_stack.push(env); \
continue; /* TCO */ \
}
#define EVAL_IF(ast, nodes, env) \
{ \
if (nodes.size() != 2 && nodes.size() != 3) { \
Error::the().add(format("wrong number of arguments: if, {}", nodes.size())); \
return nullptr; \
} \
\
auto first_argument = *nodes.begin(); \
auto second_argument = *std::next(nodes.begin()); \
auto third_argument = (nodes.size() == 3) ? *std::next(std::next(nodes.begin())) : makePtr<Value>(Value::Nil); \
\
m_ast_stack.push(first_argument); \
m_env_stack.push(env); \
auto first_evaluated = evalImpl(); \
if (!is<Value>(first_evaluated.get()) \
|| std::static_pointer_cast<Value>(first_evaluated)->state() == Value::True) { \
m_ast_stack.push(second_argument); \
m_env_stack.push(env); \
continue; /* TCO */ \
} \
else { \
m_ast_stack.push(third_argument); \
m_env_stack.push(env); \
continue; /* TCO */ \
} \
}
void Eval::eval()
{
m_ast_stack = std::stack<ASTNodePtr>();
@ -175,13 +76,16 @@ ASTNodePtr Eval::evalImpl()
return evalDef(nodes, env);
}
if (symbol == "let*") {
EVAL_LET(ast, nodes, env);
evalLet(nodes, env);
continue; // TCO
}
if (symbol == "do") {
EVAL_DO(ast, nodes, env);
evalDo(nodes, env);
continue; // TCO
}
if (symbol == "if") {
EVAL_IF(ast, nodes, env);
evalIf(nodes, env);
continue; // TCO
}
if (symbol == "fn*") {
return evalFn(nodes, env);
@ -291,6 +195,104 @@ ASTNodePtr Eval::evalDef(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env)
return env->set(symbol, value);
}
void Eval::evalLet(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env)
{
if (nodes.size() != 2) {
Error::the().add(format("wrong number of arguments: let*, {}", nodes.size()));
return;
}
auto first_argument = *nodes.begin();
auto second_argument = *std::next(nodes.begin());
// First argument needs to be a List or Vector
if (!is<Collection>(first_argument.get())) {
Error::the().add(format("wrong argument type: collection, '{}'", first_argument));
return;
}
// Get the nodes out of the List or Vector
std::list<ASTNodePtr> binding_nodes;
auto bindings = std::static_pointer_cast<Collection>(first_argument);
binding_nodes = bindings->nodes();
// List or Vector needs to have an even number of elements
size_t count = binding_nodes.size();
if (count % 2 != 0) {
Error::the().add(format("wrong number of arguments: {}, {}", "let* bindings", count));
return;
}
// Create new environment
auto let_env = Environment::create(env);
for (auto it = binding_nodes.begin(); it != binding_nodes.end(); std::advance(it, 2)) {
// First element needs to be a Symbol
if (!is<Symbol>(*it->get())) {
Error::the().add(format("wrong argument type: symbol, '{}'", *it));
return;
}
std::string key = std::static_pointer_cast<Symbol>(*it)->symbol();
m_ast_stack.push(*std::next(it));
m_env_stack.push(let_env);
ASTNodePtr value = evalImpl();
let_env->set(key, value);
}
// TODO: Remove limitation of 3 arguments
// Eval all values in this new env, return last sexp of the result
m_ast_stack.push(second_argument);
m_env_stack.push(let_env);
return; // TCO
}
void Eval::evalDo(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env)
{
if (nodes.size() == 0) {
Error::the().add(format("wrong number of arguments: do, {}", nodes.size()));
return;
}
// Evaluate all nodes except the last
for (auto it = nodes.begin(); it != std::prev(nodes.end(), 1); ++it) {
m_ast_stack.push(*it);
m_env_stack.push(env);
evalImpl();
}
// Eval last node
m_ast_stack.push(nodes.back());
m_env_stack.push(env);
return; // TCO
}
void Eval::evalIf(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env)
{
if (nodes.size() != 2 && nodes.size() != 3) {
Error::the().add(format("wrong number of arguments: if, {}", nodes.size()));
return;
}
auto first_argument = *nodes.begin();
auto second_argument = *std::next(nodes.begin());
auto third_argument = (nodes.size() == 3) ? *std::next(std::next(nodes.begin())) : makePtr<Value>(Value::Nil);
m_ast_stack.push(first_argument);
m_env_stack.push(env);
auto first_evaluated = evalImpl();
if (!is<Value>(first_evaluated.get())
|| std::static_pointer_cast<Value>(first_evaluated)->state() == Value::True) {
m_ast_stack.push(second_argument);
m_env_stack.push(env);
return; // TCO
}
m_ast_stack.push(third_argument);
m_env_stack.push(env);
return; // TCO
}
#define ARG_COUNT_CHECK(name, comparison, size) \
if (comparison) { \
Error::the().add(format("wrong number of arguments: {}, {}", name, size)); \

3
src/eval.h

@ -29,6 +29,9 @@ private:
ASTNodePtr evalImpl();
ASTNodePtr evalAst(ASTNodePtr ast, EnvironmentPtr env);
ASTNodePtr evalDef(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env);
void evalLet(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env);
void evalDo(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env);
void evalIf(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env);
ASTNodePtr evalFn(const std::list<ASTNodePtr>& nodes, EnvironmentPtr env);
ASTNodePtr apply(std::shared_ptr<List> evaluated_list);

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