From 1014462963f3a15a191228dd7f42375b55dbdd25 Mon Sep 17 00:00:00 2001
From: Adam Wardynski <award@.(win7-laptop)>
Date: Thu, 18 Nov 2010 18:36:24 +0100
Subject: [PATCH] Const contract on function return Value. Generally we want to
avoid accidental change of value of a constant or of a variable. Originally
I'd copy value on access, but this changed it so a const Value is returned
instead and copy is done only when it's needed.
---
libwccl/ops/affix.cpp | 2 +-
libwccl/ops/constant.h | 7 +++----
libwccl/ops/functions.h | 8 ++++----
libwccl/ops/regex.cpp | 2 +-
libwccl/ops/tolower.cpp | 4 ++--
libwccl/ops/toupper.cpp | 2 +-
tests/constant_tests.cpp | 10 ----------
7 files changed, 12 insertions(+), 23 deletions(-)
diff --git a/libwccl/ops/affix.cpp b/libwccl/ops/affix.cpp
index 59562af..934787d 100644
--- a/libwccl/ops/affix.cpp
+++ b/libwccl/ops/affix.cpp
@@ -25,7 +25,7 @@ Affix::BaseRetValPtr Affix::apply_internal(const FunExecContext& context) const
if(affix_length_ == 0) {
return strset_expr_->apply(context);
}
- const boost::shared_ptr<StrSet>& set = strset_expr_->apply(context);
+ const boost::shared_ptr<const StrSet>& set = strset_expr_->apply(context);
boost::shared_ptr<StrSet> a_set = boost::shared_ptr<StrSet>(new StrSet());
if(affix_length_ < 0) {
foreach(const UnicodeString& s, set->contents()) {
diff --git a/libwccl/ops/constant.h b/libwccl/ops/constant.h
index c5c933f..c9bb5d8 100644
--- a/libwccl/ops/constant.h
+++ b/libwccl/ops/constant.h
@@ -1,7 +1,6 @@
#ifndef LIBWCCL_OPS_CONSTANT_H
#define LIBWCCL_OPS_CONSTANT_H
-#include <boost/scoped_ptr.hpp>
#include <boost/concept_check.hpp>
#include <libwccl/ops/functions.h>
@@ -45,12 +44,12 @@ protected :
/**
* Applying Constant function returns the held value of a constant
*/
- virtual BaseRetValPtr apply_internal(const FunExecContext&) const {
- return BaseRetValPtr (new T(*value_));
+ BaseRetValPtr apply_internal(const FunExecContext&) const {
+ return value_;
}
private:
- const boost::scoped_ptr<const T> value_;
+ const boost::shared_ptr<const T> value_;
};
diff --git a/libwccl/ops/functions.h b/libwccl/ops/functions.h
index 34acfe0..bda8751 100644
--- a/libwccl/ops/functions.h
+++ b/libwccl/ops/functions.h
@@ -17,9 +17,9 @@ namespace Wccl {
*/
class FunctionBase : public Operator {
protected:
- typedef boost::shared_ptr<Value> BaseRetValPtr;
+ typedef boost::shared_ptr<const Value> BaseRetValPtr;
/**
- * Applies the function, given the sentence context.
+ * Applies the function for the given execution context.
*/
virtual BaseRetValPtr apply_internal(const FunExecContext& context) const = 0;
};
@@ -37,7 +37,7 @@ public:
* Type returned after application of function (shared pointer to
* a variable of the specified return type)
*/
- typedef boost::shared_ptr<T> RetValPtr;
+ typedef boost::shared_ptr<const T> RetValPtr;
/**
* Applies the function, given the sentence context, returning specific
@@ -45,7 +45,7 @@ public:
* be specified in derived classes.
*/
RetValPtr apply(const FunExecContext& context) const {
- RetValPtr v = boost::dynamic_pointer_cast<T>(apply_internal(context));
+ RetValPtr v = boost::dynamic_pointer_cast<const T>(apply_internal(context));
BOOST_ASSERT(v);
return v;
}
diff --git a/libwccl/ops/regex.cpp b/libwccl/ops/regex.cpp
index 0c4dca7..4759ea9 100644
--- a/libwccl/ops/regex.cpp
+++ b/libwccl/ops/regex.cpp
@@ -73,7 +73,7 @@ std::string Regex::to_raw_string() const {
}
Regex::BaseRetValPtr Regex::apply_internal(const FunExecContext& context) const {
- const boost::shared_ptr<StrSet>& set = strset_expr_->apply(context);
+ const boost::shared_ptr<const StrSet>& set = strset_expr_->apply(context);
if(set->empty()) {
return Predicate::False->apply(context);
}
diff --git a/libwccl/ops/tolower.cpp b/libwccl/ops/tolower.cpp
index 52ad8c3..f88ce8a 100644
--- a/libwccl/ops/tolower.cpp
+++ b/libwccl/ops/tolower.cpp
@@ -12,8 +12,8 @@ std::string ToLower::to_raw_string() const {
return UnaryFunctionFormatter::to_raw_string(*this, *strset_expr_);
}
-ToLower::BaseRetValPtr ToLower::apply_internal(const FunExecContext& context) const {
- const boost::shared_ptr<StrSet >& set = strset_expr_->apply(context);
+ToLower::BaseRetValPtr ToLower::apply_internal(const FunExecContext& context) const {
+ const boost::shared_ptr<const StrSet >& set = strset_expr_->apply(context);
boost::shared_ptr<StrSet > l_set = boost::make_shared<StrSet>();
//TODO: should tolower be a method of StrSet as well?
foreach(const UnicodeString& s, set->contents()) {
diff --git a/libwccl/ops/toupper.cpp b/libwccl/ops/toupper.cpp
index ec55211..edbc3c7 100644
--- a/libwccl/ops/toupper.cpp
+++ b/libwccl/ops/toupper.cpp
@@ -13,7 +13,7 @@ std::string ToUpper::to_raw_string() const {
}
ToUpper::BaseRetValPtr ToUpper::apply_internal(const FunExecContext& context) const {
- const boost::shared_ptr<StrSet >& set = strset_expr_->apply(context);
+ const boost::shared_ptr<const StrSet >& set = strset_expr_->apply(context);
boost::shared_ptr<StrSet > u_set = boost::make_shared<StrSet>();
//TODO: should tolower be a method of StrSet as well?
foreach(const UnicodeString& s, set->contents()) {
diff --git a/tests/constant_tests.cpp b/tests/constant_tests.cpp
index b4754c7..08e1f02 100644
--- a/tests/constant_tests.cpp
+++ b/tests/constant_tests.cpp
@@ -58,14 +58,4 @@ BOOST_FIXTURE_TEST_CASE(bool_to_raw_string, BoolFix)
BOOST_CHECK_EQUAL(false_value.to_raw_string(), false_constant.to_raw_string());
}
-BOOST_FIXTURE_TEST_CASE(bool_value_preserved, BoolFix)
-{
- boost::shared_ptr<Bool> v = true_constant.apply(cx);
- v->set_value(false);
- BOOST_CHECK_EQUAL(true, true_constant.apply(cx)->get_value());
- v = false_constant.apply(cx);
- v->set_value(true);
- BOOST_CHECK_EQUAL(false, false_constant.apply(cx)->get_value());
-}
-
BOOST_AUTO_TEST_SUITE_END()
--
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