From 89f3eb0306f71495fcce6a4a486335026e985f1f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20L=C3=BChne?= <patrick-github@luehne.de>
Date: Thu, 31 Aug 2017 18:34:34 +0200
Subject: [PATCH] Implemented term parser.

---
 .../include/pddl/detail/parsing/Expressions.h | 10 +++++
 lib/pddl/include/pddl/detail/parsing/Term.h   | 27 ++++++++++++
 .../src/pddl/detail/parsing/AtomicFormula.cpp | 18 +++-----
 lib/pddl/src/pddl/detail/parsing/Term.cpp     | 42 +++++++++++++++++++
 4 files changed, 84 insertions(+), 13 deletions(-)
 create mode 100644 lib/pddl/include/pddl/detail/parsing/Term.h
 create mode 100644 lib/pddl/src/pddl/detail/parsing/Term.cpp

diff --git a/lib/pddl/include/pddl/detail/parsing/Expressions.h b/lib/pddl/include/pddl/detail/parsing/Expressions.h
index cfb676e..970aad2 100644
--- a/lib/pddl/include/pddl/detail/parsing/Expressions.h
+++ b/lib/pddl/include/pddl/detail/parsing/Expressions.h
@@ -25,6 +25,8 @@ template<typename Argument, typename ArgumentParser>
 std::experimental::optional<ast::AtPointer<Argument>> parseAt(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentParser parseArgument);
 template<typename Argument, typename ArgumentParser>
 std::experimental::optional<ast::EitherPointer<Argument>> parseEither(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentParser parseArgument);
+template<typename ArgumentLeft, typename ArgumentRight, typename ArgumentLeftParser, typename ArgumentRightParser>
+std::experimental::optional<ast::EqualsPointer<ArgumentLeft, ArgumentRight>> parseEquals(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentLeftParser parseArgumentLeft, ArgumentRightParser parseArgumentRight);
 template<typename Argument, typename ArgumentParser>
 std::experimental::optional<ast::ExistsPointer<Argument>> parseExists(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentParser parseArgument);
 template<typename Argument, typename ArgumentParser>
@@ -177,6 +179,14 @@ std::experimental::optional<ast::EitherPointer<Argument>> parseEither(Context &c
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+template<typename ArgumentLeft, typename ArgumentRight, typename ArgumentLeftParser, typename ArgumentRightParser>
+std::experimental::optional<ast::EqualsPointer<ArgumentLeft, ArgumentRight>> parseEquals(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentLeftParser parseArgumentLeft, ArgumentRightParser parseArgumentRight)
+{
+	return parseBinary<ast::Equals<ArgumentLeft, ArgumentRight>, ArgumentLeftParser, ArgumentRightParser>(context, astContext, variableStack, parseArgumentLeft, parseArgumentRight);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 template<typename Argument, typename ArgumentParser>
 std::experimental::optional<ast::ExistsPointer<Argument>> parseExists(Context &context, ASTContext &astContext, VariableStack &variableStack, ArgumentParser parseArgument)
 {
diff --git a/lib/pddl/include/pddl/detail/parsing/Term.h b/lib/pddl/include/pddl/detail/parsing/Term.h
new file mode 100644
index 0000000..6304e9e
--- /dev/null
+++ b/lib/pddl/include/pddl/detail/parsing/Term.h
@@ -0,0 +1,27 @@
+#ifndef __PDDL__DETAIL__PARSING__TERM_H
+#define __PDDL__DETAIL__PARSING__TERM_H
+
+#include <pddl/ASTForward.h>
+#include <pddl/Context.h>
+#include <pddl/detail/ASTContext.h>
+#include <pddl/detail/VariableStack.h>
+
+namespace pddl
+{
+namespace detail
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Type
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+std::experimental::optional<ast::Term> parseTerm(Context &context, ASTContext &astContext, VariableStack &variableStack);
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}
+
+#endif
diff --git a/lib/pddl/src/pddl/detail/parsing/AtomicFormula.cpp b/lib/pddl/src/pddl/detail/parsing/AtomicFormula.cpp
index 98e7a80..3bd7117 100644
--- a/lib/pddl/src/pddl/detail/parsing/AtomicFormula.cpp
+++ b/lib/pddl/src/pddl/detail/parsing/AtomicFormula.cpp
@@ -1,8 +1,9 @@
 #include <pddl/detail/parsing/AtomicFormula.h>
 
 #include <pddl/AST.h>
+#include <pddl/detail/parsing/Expressions.h>
 #include <pddl/detail/parsing/Predicate.h>
-#include <pddl/detail/parsing/Unsupported.h>
+#include <pddl/detail/parsing/Term.h>
 
 namespace pddl
 {
@@ -17,20 +18,11 @@ namespace detail
 
 std::experimental::optional<ast::AtomicFormula> parseAtomicFormula(Context &context, ASTContext &astContext, VariableStack &variableStack)
 {
-	auto &tokenizer = context.tokenizer;
+	std::experimental::optional<ast::AtomicFormula> atomicFormula;
 
-	// Test unsupported expressions first
-	const auto position = tokenizer.position();
+	if ((atomicFormula = parseEquals<ast::Term, ast::Term>(context, astContext, variableStack, parseTerm, parseTerm)))
+		return std::move(atomicFormula.value());
 
-	tokenizer.expect<std::string>("(");
-	tokenizer.skipWhiteSpace();
-
-	if (tokenizer.testIdentifierAndReturn("="))
-		throw exceptUnsupportedExpression(position, context);
-
-	tokenizer.seek(position);
-
-	// Now, test supported expressions
 	return parsePredicate(context, astContext, variableStack);
 }
 
diff --git a/lib/pddl/src/pddl/detail/parsing/Term.cpp b/lib/pddl/src/pddl/detail/parsing/Term.cpp
new file mode 100644
index 0000000..d0d9e66
--- /dev/null
+++ b/lib/pddl/src/pddl/detail/parsing/Term.cpp
@@ -0,0 +1,42 @@
+#include <pddl/detail/parsing/Term.h>
+
+#include <pddl/Exception.h>
+#include <pddl/detail/parsing/Constant.h>
+#include <pddl/detail/parsing/Variable.h>
+
+namespace pddl
+{
+namespace detail
+{
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+// Term
+//
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+std::experimental::optional<ast::Term> parseTerm(Context &context, ASTContext &astContext, VariableStack &variableStack)
+{
+	auto &tokenizer = context.tokenizer;
+
+	tokenizer.skipWhiteSpace();
+
+	// TODO: refactor
+	auto variable = testParsingVariable(context, variableStack);
+
+	if (variable)
+		return std::move(variable.value());
+
+	// Parse argument if it is a constant
+	auto constant = testParsingConstant(context, astContext);
+
+	if (constant)
+		return std::move(constant.value());
+
+	return std::experimental::nullopt;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+}
+}