Returns the length of a string.

Without a unit argument, the length is counted in codepoints, unless the backwards-compatibility key config :ash, :default_string_length_count is set to :mixed, in which case it is counted in graphemes (see the backwards compatibility guide). An optional second argument selects a unit explicitly:

• :graphemes - counts unicode graphemes, i.e String.length/1.
• :codepoints - counts unicode codepoints. This matches how most SQL data layers count the length of a string.
• :bytes - counts bytes, i.e byte_size/1.

A single grapheme may be made up of an unbounded number of codepoints (e.g. a base character followed by many combining marks), so counting graphemes places no effective bound on the size of a value. Use :codepoints or :bytes when the length is being used as a limit.

Data layers cannot count graphemes, so :graphemes is only supported where the expression is evaluated in Elixir. Note that string_length/1 is translated to the data layer's native length function, which counts codepoints, regardless of the configured default.

string_length(name)
string_length(name, :bytes)