Add FormatValue for TPiecewiseLinearFunction

commit_hash:19d66bcbea30c7678ee476930a8fa6b7f78bb22a

Author: ignat

yt/yt/library/numeric/piecewise_linear_function-inl.h

@@ -1130,6 +1130,25 @@ bool operator==(const TPiecewiseLinearFunction<TValue>& lhs, const TPiecewiseLin
     return lhs.Segments() == rhs.Segments();
 }
 
+template <class TValue>
+void FormatValue(TStringBuilderBase* builder, const TPiecewiseLinearFunction<TValue>& func, TStringBuf spec)
+{
+    builder->AppendChar('[');
+    const auto& segments = func.Segments();
+    if (!segments.empty()) {
+        FormatValue(builder, segments[0].LeftBound(), spec);
+        builder->AppendString(": ");
+        FormatValue(builder, segments[0].LeftValue(), spec);
+        for (size_t index = 1; index < segments.size(); index++) {
+            builder->AppendString(", ");
+            FormatValue(builder, segments[0].RightBound(), spec);
+            builder->AppendString(": ");
+            FormatValue(builder, segments[0].RightValue(), spec);
+        }
+    }
+    builder->AppendChar(']');
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT

yt/yt/library/numeric/piecewise_linear_function.h

@@ -5,6 +5,8 @@
 
 #include <library/cpp/testing/gtest/friend.h>
 
+#include <library/cpp/yt/string/format.h>
+
 #include <util/system/yassert.h>
 #include <util/generic/algorithm.h>
 #include <util/generic/yexception.h>
@@ -434,6 +436,9 @@ class TPiecewiseLinearFunction
 template <class TValue>
 bool operator==(const TPiecewiseLinearFunction<TValue>& lhs, const TPiecewiseLinearFunction<TValue>& rhs);
 
+template <class TValue>
+void FormatValue(TStringBuilderBase* builder, const TPiecewiseLinearFunction<TValue>& func, TStringBuf spec);
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT