From ab27e8699ef2a2bafe574158200993f184de3dc2 Mon Sep 17 00:00:00 2001 From: Serge Aleynikov Date: Mon, 21 Jan 2013 15:36:43 +0100 Subject: Text representation of a float formatted using given options. This BIF solves a problem of float_to_list/1 that doesn't allow specifying the number of digits after the decimal point when formatting floats. float_to_list(Float, Options) -> string() Float = float() Options = [Option] Option = {decimals, Decimals::0..249} | {scientific, Decimals::0..249} | compact Returns a string which corresponds to the text representation of a `Float` formatted using given options. When decimals option is specified the returned value will contain at most `Decimals` number of digits past the decimal point. When `compact` option is provided the trailing zeros at the end of the list are truncated (this option is only meaningful together with the `decimals` option). When `scientific` option is provided, the float will be formatted using scientific notation with `Decimals` digits of precision. If `Options` is `[]` the function behaves like `float_to_list/1`. When using `decimals` option and the number doesn't fit in the static internal buffer of 256 bytes the function throws `badarg`. --- erts/doc/src/erlang.xml | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 1d67be2e52..95862216b8 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -967,6 +967,37 @@ true "7.00000000000000000000e+00" + + float_to_list(Float, Options) -> string() + Text representation of a float formatted using given options + + Float = float() + Options = [Option] + Option = {decimals, Decimals::0..249} | + {scientific, Decimals::0..249} | + compact + + +

Returns a string which corresponds to the text + representation of Float using fixed decimal point formatting. + When decimals option is specified + the returned value will contain at most Decimals number of + digits past the decimal point. If the number doesn't fit in the + internal static buffer of 256 bytes, the function throws badarg. + When compact option is provided + the trailing zeros at the end of the list are truncated (this option is + only meaningful together with the decimals option). When + scientific option is provided, the float will be formatted using + scientific notation with Decimals digits of precision. If + Options is [] the function behaves like float_to_list/1. +

+
+> float_to_list(7.12, [{decimals, 4}]).
+"7.1200"
+> float_to_list(7.12, [{decimals, 4}, compact]).
+"7.12"
+
+
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