" Vim indent file " Language: Rust " Author: Chris Morgan <me@chrismorgan.info> " Last Change: 2017 Jun 13 " For bugs, patches and license go to https://github.com/rust-lang/rust.vim " Only load this indent file when no other was loaded. if exists("b:did_indent") finish endif let b:did_indent = 1 setlocal cindent setlocal cinoptions=L0,(0,Ws,J1,j1 setlocal cinkeys=0{,0},!^F,o,O,0[,0] " Don't think cinwords will actually do anything at all... never mind setlocal cinwords=for,if,else,while,loop,impl,mod,unsafe,trait,struct,enum,fn,extern " Some preliminary settings setlocal nolisp " Make sure lisp indenting doesn't supersede us setlocal autoindent " indentexpr isn't much help otherwise " Also do indentkeys, otherwise # gets shoved to column 0 :-/ setlocal indentkeys=0{,0},!^F,o,O,0[,0] setlocal indentexpr=GetRustIndent(v:lnum) " Only define the function once. if exists("*GetRustIndent") finish endif let s:save_cpo = &cpo set cpo&vim " Come here when loading the script the first time. function! s:get_line_trimmed(lnum) " Get the line and remove a trailing comment. " Use syntax highlighting attributes when possible. " NOTE: this is not accurate; /* */ or a line continuation could trick it let line = getline(a:lnum) let line_len = strlen(line) if has('syntax_items') " If the last character in the line is a comment, do a binary search for " the start of the comment. synID() is slow, a linear search would take " too long on a long line. if synIDattr(synID(a:lnum, line_len, 1), "name") =~ 'Comment\|Todo' let min = 1 let max = line_len while min < max let col = (min + max) / 2 if synIDattr(synID(a:lnum, col, 1), "name") =~ 'Comment\|Todo' let max = col else let min = col + 1 endif endwhile let line = strpart(line, 0, min - 1) endif return substitute(line, "\s*$", "", "") else " Sorry, this is not complete, nor fully correct (e.g. string "//"). " Such is life. return substitute(line, "\s*//.*$", "", "") endif endfunction function! s:is_string_comment(lnum, col) if has('syntax_items') for id in synstack(a:lnum, a:col) let synname = synIDattr(id, "name") if synname == "rustString" || synname =~ "^rustComment" return 1 endif endfor else " without syntax, let's not even try return 0 endif endfunction function GetRustIndent(lnum) " Starting assumption: cindent (called at the end) will do it right " normally. We just want to fix up a few cases. let line = getline(a:lnum) if has('syntax_items') let synname = synIDattr(synID(a:lnum, 1, 1), "name") if synname == "rustString" " If the start of the line is in a string, don't change the indent return -1 elseif synname =~ '\(Comment\|Todo\)' \ && line !~ '^\s*/\*' " not /* opening line if synname =~ "CommentML" " multi-line if line !~ '^\s*\*' && getline(a:lnum - 1) =~ '^\s*/\*' " This is (hopefully) the line after a /*, and it has no " leader, so the correct indentation is that of the " previous line. return GetRustIndent(a:lnum - 1) endif endif " If it's in a comment, let cindent take care of it now. This is " for cases like "/*" where the next line should start " * ", not " "* " as the code below would otherwise cause for module scope " Fun fact: " /*\n*\n*/" takes two calls to get right! return cindent(a:lnum) endif endif " cindent gets second and subsequent match patterns/struct members wrong, " as it treats the comma as indicating an unfinished statement:: " " match a { " b => c, " d => e, " f => g, " }; " Search backwards for the previous non-empty line. let prevlinenum = prevnonblank(a:lnum - 1) let prevline = s:get_line_trimmed(prevlinenum) while prevlinenum > 1 && prevline !~ '[^[:blank:]]' let prevlinenum = prevnonblank(prevlinenum - 1) let prevline = s:get_line_trimmed(prevlinenum) endwhile " Handle where clauses nicely: subsequent values should line up nicely. if prevline[len(prevline) - 1] == "," \ && prevline =~# '^\s*where\s' return indent(prevlinenum) + 6 endif if prevline[len(prevline) - 1] == "," \ && s:get_line_trimmed(a:lnum) !~ '^\s*[\[\]{}]' \ && prevline !~ '^\s*fn\s' \ && prevline !~ '([^()]\+,$' \ && s:get_line_trimmed(a:lnum) !~ '^\s*\S\+\s*=>' " Oh ho! The previous line ended in a comma! I bet cindent will try to " take this too far... For now, let's normally use the previous line's " indent. " One case where this doesn't work out is where *this* line contains " square or curly brackets; then we normally *do* want to be indenting " further. " " Another case where we don't want to is one like a function " definition with arguments spread over multiple lines: " " fn foo(baz: Baz, " baz: Baz) // <-- cindent gets this right by itself " " Another case is similar to the previous, except calling a function " instead of defining it, or any conditional expression that leaves " an open paren: " " foo(baz, " baz); " " if baz && (foo || " bar) { " " Another case is when the current line is a new match arm. " " There are probably other cases where we don't want to do this as " well. Add them as needed. return indent(prevlinenum) endif if !has("patch-7.4.355") " cindent before 7.4.355 doesn't do the module scope well at all; e.g.:: " " static FOO : &'static [bool] = [ " true, " false, " false, " true, " ]; " " uh oh, next statement is indented further! " Note that this does *not* apply the line continuation pattern properly; " that's too hard to do correctly for my liking at present, so I'll just " start with these two main cases (square brackets and not returning to " column zero) call cursor(a:lnum, 1) if searchpair('{\|(', '', '}\|)', 'nbW', \ 's:is_string_comment(line("."), col("."))') == 0 if searchpair('\[', '', '\]', 'nbW', \ 's:is_string_comment(line("."), col("."))') == 0 " Global scope, should be zero return 0 else " At the module scope, inside square brackets only "if getline(a:lnum)[0] == ']' || search('\[', '', '\]', 'nW') == a:lnum if line =~ "^\\s*]" " It's the closing line, dedent it return 0 else return shiftwidth() endif endif endif endif " Fall back on cindent, which does it mostly right return cindent(a:lnum) endfunction let &cpo = s:save_cpo unlet s:save_cpo