From: akr@... Date: 2020-12-26T11:07:29+00:00 Subject: [ruby-core:101709] [Ruby master Feature#16005] A variation of Time.iso8601 that can parse yyyy-MM-dd HH:mm:ss Issue #16005 has been updated by akr (Akira Tanaka). We (akr, naruse and matsuda) discussed this issue. - implementing this method, Time.sql_timestamp(string), in time.c would be faster implementation than Ruby version because it avoids several string object allocations: `/(\d+)-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)/ =~ str; Time.new($1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i);` $1...$6 allocates strings but C-implementation can avoid them - `Time.sql_timestamp("yyyy-mm-dd HH:MM:SS")` returns a Time object in UTC mode and `Time.sql_timestamp("yyyy-mm-dd HH:MM:SS +HH:MM")` returns a Time object in fixed-offset mode. If an application needs to interpret "yyyy-mm-dd HH:MM:SS" as local time, the application can instantiate a new Time object as `t = Time.sql_timestamp(string); t = Time.new(t.year, t.month, t.day, t.hour, t.min, t.sec) if t.utc?` ---------------------------------------- Feature #16005: A variation of Time.iso8601 that can parse yyyy-MM-dd HH:mm:ss https://bugs.ruby-lang.org/issues/16005#change-89533 * Author: matsuda (Akira Matsuda) * Status: Open * Priority: Normal * Target version: 3.1 ---------------------------------------- Let me propose a String to Time conversion method that can parse "yyyy-MM-dd HH:mm:ss" format, which is very much similar to `Time.iso8601`, but delimits the date part and the time part with a space character. This format is defined as the "timestamp string" literal in SQL 92 standard: http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt (see P. 90) and so this format is very widely used as the default datetime / timestamp literal for major existing RDBMS implementations. Oracle https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/Literals.html#GUID-8F4B3F82-8821-4071-84D6-FBBA21C05AC1 SQL Server https://docs.microsoft.com/en-us/sql/odbc/reference/develop-app/date-time-and-timestamp-literals?view=sql-server-2017 PostgreSQL https://www.postgresql.org/docs/11/datatype-datetime.html#id-1.5.7.13.19.7.2 MySQL https://dev.mysql.com/doc/refman/8.0/en/datetime.html SQLite3 https://www.sqlite.org/lang_datefunc.html In order to handle this conversion in Ruby on Rails framework, we define our own String => Time conversion method https://github.com/rails/rails/blob/b4c715fe/activemodel/lib/active_model/type/helpers/time_value.rb#L62-L76 and Time => String conversion for now, https://github.com/rails/rails/blob/b4c715fe/activesupport/lib/active_support/core_ext/time/conversions.rb#L7-L59 and I think it's nicer if we had them in the language level with a faster implementation. As for the method name, maybe we can name it `Time.sql92`, `Time.sql`, `Time.parse_sql92` or whatever, or maybe we can add an option to `Time.iso8601` if it could be regarded as a variation of `Time.iso8601`? (https://en.wikipedia.org/wiki/ISO_8601#cite_note-30) -- https://bugs.ruby-lang.org/ Unsubscribe: