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Posted to commits@quickstep.apache.org by zu...@apache.org on 2016/06/08 19:19:12 UTC
[20/44] incubator-quickstep git commit: Added a method for double
parsing with significant number argument. (#216)
Added a method for double parsing with significant number argument. (#216)
Project: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/commit/19aeb6c5
Tree: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/tree/19aeb6c5
Diff: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/diff/19aeb6c5
Branch: refs/heads/master
Commit: 19aeb6c5d5985312978a0dfdca24777bd8d552cd
Parents: d75ae42
Author: Hakan Memisoglu <ha...@gmail.com>
Authored: Sun May 8 08:22:17 2016 -0500
Committer: Zuyu Zhang <zz...@pivotal.io>
Committed: Wed Jun 8 11:57:42 2016 -0700
----------------------------------------------------------------------
utility/StringUtil.cpp | 14 ++++++++++++++
utility/StringUtil.hpp | 18 ++++++++++++++++++
2 files changed, 32 insertions(+)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/incubator-quickstep/blob/19aeb6c5/utility/StringUtil.cpp
----------------------------------------------------------------------
diff --git a/utility/StringUtil.cpp b/utility/StringUtil.cpp
index 77b0a3a..b38e8f4 100644
--- a/utility/StringUtil.cpp
+++ b/utility/StringUtil.cpp
@@ -22,10 +22,13 @@
#include <algorithm>
#include <cctype>
#include <cinttypes>
+#include <cmath>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
+#include <iomanip>
+#include <sstream>
#include <string>
#include <vector>
@@ -128,4 +131,15 @@ string ToZeroPaddedString(std::uint64_t val, int pad_width) {
return result;
}
+std::string
+DoubleToStringWithSignificantDigits(double val,
+ std::uint64_t significant_digits) {
+ std::uint64_t precision_needed =
+ (val >= 1.0) ? significant_digits
+ : significant_digits + -(std::trunc(std::log10(val)));
+ std::stringstream string_buffer;
+ string_buffer << std::fixed << std::setprecision(precision_needed) << val;
+ return string_buffer.str();
+}
+
} // namespace quickstep
http://git-wip-us.apache.org/repos/asf/incubator-quickstep/blob/19aeb6c5/utility/StringUtil.hpp
----------------------------------------------------------------------
diff --git a/utility/StringUtil.hpp b/utility/StringUtil.hpp
index 26c04a4..bd138bb 100644
--- a/utility/StringUtil.hpp
+++ b/utility/StringUtil.hpp
@@ -70,6 +70,24 @@ extern bool ParseIntString(const std::string &int_string,
*/
extern std::string ToZeroPaddedString(std::uint64_t val, int pad_width);
+
+/**
+ * @brief Parse double with significant digits.
+ *
+ * @param val The value that will be parsed.
+ * @param significant_digit The number of non-zero digits that will be parsed
+ * in the fraction part of double.
+ * @return Corresponding string representation of parsed double.
+ * Ex:
+ * DoubleToStringWithSignificantDigits(3.124355123, 3)
+ * => 3.124
+ * DoubleToStringWithSignificantDigits(0.00000000323411, 3)
+ * => 0.00000000323
+ **/
+extern std::string
+DoubleToStringWithSignificantDigits(double val,
+ std::uint64_t significant_digits);
+
/** @} */
} // namespace quickstep