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-rw-r--r--contrib/fpconv/fpconv.h35
1 files changed, 35 insertions, 0 deletions
diff --git a/contrib/fpconv/fpconv.h b/contrib/fpconv/fpconv.h
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+#ifndef FPCONV_H
+#define FPCONV_H
+
+#define FPCONV_BUFLEN 32
+/* Fast and accurate double to string conversion based on Florian Loitsch's
+ * Grisu-algorithm[1].
+ *
+ * Input:
+ * fp -> the double to convert, dest -> destination buffer.
+ * The generated string will never be longer than 24 characters.
+ * Make sure to pass a pointer to at least 24 bytes of memory.
+ * The emitted string will not be null terminated.
+ *
+ * Output:
+ * The number of written characters.
+ *
+ * Exemplary usage:
+ *
+ * void print(double d)
+ * {
+ * char buf[24 + 1] // plus null terminator
+ * int str_len = fpconv_dtoa(d, buf);
+ *
+ * buf[str_len] = '\0';
+ * printf("%s", buf);
+ * }
+ *
+ */
+
+int fpconv_dtoa(double fp, char dest[FPCONV_BUFLEN], unsigned precision,
+ bool scientific);
+
+#endif
+
+/* [1] http://florian.loitsch.com/publications/dtoa-pldi2010.pdf */