[libcamera-devel,v2,02/10] libcamera: utils: Add string join function
diff mbox series

Message ID 20200316214310.27665-3-laurent.pinchart@ideasonboard.com
State Superseded
Headers show
Series
  • Simple pipeline handler
Related show

Commit Message

Laurent Pinchart March 16, 2020, 9:43 p.m. UTC 
Add a utils::join() function to join elements of a container into a
string, with a separator and an optional conversion function if the
elements are not implicitly convertible to std::string.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/libcamera/include/utils.h | 44 +++++++++++++++++++++++++++++++++++
 src/libcamera/utils.cpp       | 16 +++++++++++++
 test/utils.cpp                |  7 +++++-
 3 files changed, 66 insertions(+), 1 deletion(-)

Comments

Jacopo Mondi March 17, 2020, 12:06 p.m. UTC | #1 
Hi Laurent,

On Mon, Mar 16, 2020 at 11:43:02PM +0200, Laurent Pinchart wrote:
> Add a utils::join() function to join elements of a container into a
> string, with a separator and an optional conversion function if the
> elements are not implicitly convertible to std::string.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> ---
>  src/libcamera/include/utils.h | 44 +++++++++++++++++++++++++++++++++++
>  src/libcamera/utils.cpp       | 16 +++++++++++++
>  test/utils.cpp                |  7 +++++-
>  3 files changed, 66 insertions(+), 1 deletion(-)
>
> diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
> index 940597760ee2..74ceed760cb3 100644
> --- a/src/libcamera/include/utils.h
> +++ b/src/libcamera/include/utils.h
> @@ -11,6 +11,7 @@
>  #include <chrono>
>  #include <memory>
>  #include <ostream>
> +#include <sstream>
>  #include <string>
>  #include <string.h>
>  #include <sys/time.h>
> @@ -109,6 +110,49 @@ inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
>
>  size_t strlcpy(char *dst, const char *src, size_t size);
>
> +#ifndef __DOXYGEN__
> +template<typename Container, typename UnaryOp>
> +std::string join(const Container &items, const std::string &sep, UnaryOp op)
> +{
> +	std::ostringstream ss;
> +	bool first = true;
> +
> +	for (typename Container::const_iterator it = std::begin(items);
> +	     it != std::end(items); ++it) {
> +		if (!first)
> +			ss << sep;
> +		else
> +			first = false;
> +
> +		ss << op(*it);
> +	}
> +
> +	return ss.str();
> +}
> +
> +template<typename Container>
> +std::string join(const Container &items, const std::string &sep)
> +{
> +	std::ostringstream ss;
> +	bool first = true;
> +
> +	for (typename Container::const_iterator it = std::begin(items);
> +	     it != std::end(items); ++it) {
> +		if (!first)
> +			ss << sep;
> +		else
> +			first = false;
> +
> +		ss << *it;
> +	}
> +
> +	return ss.str();
> +}
> +#else
> +template<typename Container, typename UnaryOp>
> +std::string join(const Container &items, const std::string &sep, UnaryOp op = nullptr);

What does thi give us ?

op is defaulted to nullptr, but it requires the template argument to
be specified anyway...

Apart from this
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

Thanks
  j

> +#endif
> +
>  namespace details {
>
>  class StringSplitter
> diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
> index f566e88cec5b..1d0e583756cf 100644
> --- a/src/libcamera/utils.cpp
> +++ b/src/libcamera/utils.cpp
> @@ -291,6 +291,22 @@ details::StringSplitter::iterator details::StringSplitter::end() const
>  	return iterator(this, std::string::npos);
>  }
>
> +/**
> + * \fn template<typename Container, typename UnaryOp> \
> + * std::string utils::join(const Container &items, const std::string &sep, UnaryOp op)
> + * \brief Join elements of a container in a string with a separator
> + * \param[in] items The container
> + * \param[in] sep The separator to add between elements
> + * \param[in] op A function that converts individual elements to strings
> + *
> + * This function joins all elements in the \a items container into a string and
> + * returns it. The \a sep separator is added between elements. If the container
> + * elements are not implicitly convertible to std::string, the \a op function
> + * shall be provided to perform conversion of elements to std::string.
> + *
> + * \return A string that concatenates all elements in the container
> + */
> +
>  /**
>   * \fn split(const std::string &str, const std::string &delim)
>   * \brief Split a string based on a delimiter
> diff --git a/test/utils.cpp b/test/utils.cpp
> index 58816f153066..2fca89ef3278 100644
> --- a/test/utils.cpp
> +++ b/test/utils.cpp
> @@ -99,7 +99,7 @@ protected:
>  			return TestFail;
>  		}
>
> -		/* utils::split() test. */
> +		/* utils::join() and utils::split() test. */
>  		std::vector<std::string> elements = {
>  			"/bin",
>  			"/usr/bin",
> @@ -111,6 +111,11 @@ protected:
>  		for (const auto &element : elements)
>  			path += (path.empty() ? "" : ":") + element;
>
> +		if (path != utils::join(elements, ":")) {
> +			cerr << "utils::join() test failed" << endl;
> +			return TestFail;
> +		}
> +
>  		std::vector<std::string> dirs;
>
>  		for (const auto &dir : utils::split(path, ":"))
> --
> Regards,
>
> Laurent Pinchart
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel@lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
Laurent Pinchart March 17, 2020, 8:05 p.m. UTC | #2 
Hi Jacopo,

On Tue, Mar 17, 2020 at 01:06:59PM +0100, Jacopo Mondi wrote:
> On Mon, Mar 16, 2020 at 11:43:02PM +0200, Laurent Pinchart wrote:
> > Add a utils::join() function to join elements of a container into a
> > string, with a separator and an optional conversion function if the
> > elements are not implicitly convertible to std::string.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> > ---
> >  src/libcamera/include/utils.h | 44 +++++++++++++++++++++++++++++++++++
> >  src/libcamera/utils.cpp       | 16 +++++++++++++
> >  test/utils.cpp                |  7 +++++-
> >  3 files changed, 66 insertions(+), 1 deletion(-)
> >
> > diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
> > index 940597760ee2..74ceed760cb3 100644
> > --- a/src/libcamera/include/utils.h
> > +++ b/src/libcamera/include/utils.h
> > @@ -11,6 +11,7 @@
> >  #include <chrono>
> >  #include <memory>
> >  #include <ostream>
> > +#include <sstream>
> >  #include <string>
> >  #include <string.h>
> >  #include <sys/time.h>
> > @@ -109,6 +110,49 @@ inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
> >
> >  size_t strlcpy(char *dst, const char *src, size_t size);
> >
> > +#ifndef __DOXYGEN__
> > +template<typename Container, typename UnaryOp>
> > +std::string join(const Container &items, const std::string &sep, UnaryOp op)
> > +{
> > +	std::ostringstream ss;
> > +	bool first = true;
> > +
> > +	for (typename Container::const_iterator it = std::begin(items);
> > +	     it != std::end(items); ++it) {
> > +		if (!first)
> > +			ss << sep;
> > +		else
> > +			first = false;
> > +
> > +		ss << op(*it);
> > +	}
> > +
> > +	return ss.str();
> > +}
> > +
> > +template<typename Container>
> > +std::string join(const Container &items, const std::string &sep)
> > +{
> > +	std::ostringstream ss;
> > +	bool first = true;
> > +
> > +	for (typename Container::const_iterator it = std::begin(items);
> > +	     it != std::end(items); ++it) {
> > +		if (!first)
> > +			ss << sep;
> > +		else
> > +			first = false;
> > +
> > +		ss << *it;
> > +	}
> > +
> > +	return ss.str();
> > +}
> > +#else
> > +template<typename Container, typename UnaryOp>
> > +std::string join(const Container &items, const std::string &sep, UnaryOp op = nullptr);
> 
> What does thi give us ?
> 
> op is defaulted to nullptr, but it requires the template argument to
> be specified anyway...

This is for doxygen only, in order to avoid documenting two functions
that are otherwise identical. I haven't found a way to merge both
implementations into a single template function that would make the
compiler happy.

> Apart from this
> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> 
> > +#endif
> > +
> >  namespace details {
> >
> >  class StringSplitter
> > diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
> > index f566e88cec5b..1d0e583756cf 100644
> > --- a/src/libcamera/utils.cpp
> > +++ b/src/libcamera/utils.cpp
> > @@ -291,6 +291,22 @@ details::StringSplitter::iterator details::StringSplitter::end() const
> >  	return iterator(this, std::string::npos);
> >  }
> >
> > +/**
> > + * \fn template<typename Container, typename UnaryOp> \
> > + * std::string utils::join(const Container &items, const std::string &sep, UnaryOp op)
> > + * \brief Join elements of a container in a string with a separator
> > + * \param[in] items The container
> > + * \param[in] sep The separator to add between elements
> > + * \param[in] op A function that converts individual elements to strings
> > + *
> > + * This function joins all elements in the \a items container into a string and
> > + * returns it. The \a sep separator is added between elements. If the container
> > + * elements are not implicitly convertible to std::string, the \a op function
> > + * shall be provided to perform conversion of elements to std::string.
> > + *
> > + * \return A string that concatenates all elements in the container
> > + */
> > +
> >  /**
> >   * \fn split(const std::string &str, const std::string &delim)
> >   * \brief Split a string based on a delimiter
> > diff --git a/test/utils.cpp b/test/utils.cpp
> > index 58816f153066..2fca89ef3278 100644
> > --- a/test/utils.cpp
> > +++ b/test/utils.cpp
> > @@ -99,7 +99,7 @@ protected:
> >  			return TestFail;
> >  		}
> >
> > -		/* utils::split() test. */
> > +		/* utils::join() and utils::split() test. */
> >  		std::vector<std::string> elements = {
> >  			"/bin",
> >  			"/usr/bin",
> > @@ -111,6 +111,11 @@ protected:
> >  		for (const auto &element : elements)
> >  			path += (path.empty() ? "" : ":") + element;
> >
> > +		if (path != utils::join(elements, ":")) {
> > +			cerr << "utils::join() test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> >  		std::vector<std::string> dirs;
> >
> >  		for (const auto &dir : utils::split(path, ":"))

Patch
diff mbox series 

diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h
index 940597760ee2..74ceed760cb3 100644
--- a/src/libcamera/include/utils.h
+++ b/src/libcamera/include/utils.h
@@ -11,6 +11,7 @@ 
 #include <chrono>
 #include <memory>
 #include <ostream>
+#include <sstream>
 #include <string>
 #include <string.h>
 #include <sys/time.h>
@@ -109,6 +110,49 @@  inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
 
 size_t strlcpy(char *dst, const char *src, size_t size);
 
+#ifndef __DOXYGEN__
+template<typename Container, typename UnaryOp>
+std::string join(const Container &items, const std::string &sep, UnaryOp op)
+{
+	std::ostringstream ss;
+	bool first = true;
+
+	for (typename Container::const_iterator it = std::begin(items);
+	     it != std::end(items); ++it) {
+		if (!first)
+			ss << sep;
+		else
+			first = false;
+
+		ss << op(*it);
+	}
+
+	return ss.str();
+}
+
+template<typename Container>
+std::string join(const Container &items, const std::string &sep)
+{
+	std::ostringstream ss;
+	bool first = true;
+
+	for (typename Container::const_iterator it = std::begin(items);
+	     it != std::end(items); ++it) {
+		if (!first)
+			ss << sep;
+		else
+			first = false;
+
+		ss << *it;
+	}
+
+	return ss.str();
+}
+#else
+template<typename Container, typename UnaryOp>
+std::string join(const Container &items, const std::string &sep, UnaryOp op = nullptr);
+#endif
+
 namespace details {
 
 class StringSplitter
diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp
index f566e88cec5b..1d0e583756cf 100644
--- a/src/libcamera/utils.cpp
+++ b/src/libcamera/utils.cpp
@@ -291,6 +291,22 @@  details::StringSplitter::iterator details::StringSplitter::end() const
 	return iterator(this, std::string::npos);
 }
 
+/**
+ * \fn template<typename Container, typename UnaryOp> \
+ * std::string utils::join(const Container &items, const std::string &sep, UnaryOp op)
+ * \brief Join elements of a container in a string with a separator
+ * \param[in] items The container
+ * \param[in] sep The separator to add between elements
+ * \param[in] op A function that converts individual elements to strings
+ *
+ * This function joins all elements in the \a items container into a string and
+ * returns it. The \a sep separator is added between elements. If the container
+ * elements are not implicitly convertible to std::string, the \a op function
+ * shall be provided to perform conversion of elements to std::string.
+ *
+ * \return A string that concatenates all elements in the container
+ */
+
 /**
  * \fn split(const std::string &str, const std::string &delim)
  * \brief Split a string based on a delimiter
diff --git a/test/utils.cpp b/test/utils.cpp
index 58816f153066..2fca89ef3278 100644
--- a/test/utils.cpp
+++ b/test/utils.cpp
@@ -99,7 +99,7 @@  protected:
 			return TestFail;
 		}
 
-		/* utils::split() test. */
+		/* utils::join() and utils::split() test. */
 		std::vector<std::string> elements = {
 			"/bin",
 			"/usr/bin",
@@ -111,6 +111,11 @@  protected:
 		for (const auto &element : elements)
 			path += (path.empty() ? "" : ":") + element;
 
+		if (path != utils::join(elements, ":")) {
+			cerr << "utils::join() test failed" << endl;
+			return TestFail;
+		}
+
 		std::vector<std::string> dirs;
 
 		for (const auto &dir : utils::split(path, ":"))