#3514 Elastic tabstops' interpretation of tabSize

[Xuan Baldauf]

http://www.jedit.org/users-guide/indent.html#elastic-tabstops describes elastic tabstops. There should be a distinction between standard tabSize and minimumTabSize for elastic tabstops. Typically, minimumTabSize should be 1.

Consider a text file which is formatted like this:

"\tfoo\n#\tbar"

With :tabSize=2:indentSize=2:elasticTabstops=false:, it is rendered as

foo
# bar

(2 spaces before "foo", 1 space before "bar")

However, with :tabSize=2:indentSize=2:elasticTabstops=true: , it is rendered as

foo
# bar

(3 spaces before "foo", 2 spaces before "bar").

For compatibility with other tab stop interpretations, the result should also be

foo
# bar

(2 spaces before "foo", 1 space before "bar")

Thus,
either tabSize needs to be interpreted as "offset between two starts of non-whitespace" also in elasticTabstops=true mode (as it does in elasticTabstops=false mode) instead of being interpreted as "minimum number of characters between non-whitespace",
or the concept minimumTabSize should be introduced which allows to lower the "minimum number of characters between non-whitespace" beyond the normal tabSize. The normal tabSize applies when there is white space or the start of the file before a tab '\t' (e.g. another tab or a line start), while the minimumTabSize applies when there is non-white-space before a tab '\t'. This is much more compatible to the old fixed tab stop system, where tabSize is a maximum offset, not a minimum offset and where the effective minimum offset could be as small as 1.