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Diffstat (limited to 'mnv/runtime/indent/rust.mnv')
| -rw-r--r-- | mnv/runtime/indent/rust.mnv | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/mnv/runtime/indent/rust.mnv b/mnv/runtime/indent/rust.mnv new file mode 100644 index 0000000000..a9c48e71e7 --- /dev/null +++ b/mnv/runtime/indent/rust.mnv @@ -0,0 +1,276 @@ +" MNV indent file +" Language: Rust +" Author: Chris Morgan <me@chrismorgan.info> +" Last Change: 2023-09-11 +" 2024 Jul 04 by MNV Project: use shiftwidth() instead of hard-coding shifted values #15138 +" 2025 Dec 29 by MNV Project: clean up +" 2025 Dec 31 by MNV Project: correcly indent after nested array literal #19042 +" 2026 Jan 28 by MNV Project: fix indentation when a string literal contains 'if' #19265 + +" For bugs, patches and license go to https://github.com/rust-lang/rust.mnv +" Note: upstream seems umaintained: https://github.com/rust-lang/rust.mnv/issues/502 + +" 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,(s,Ws,J1,j1,m1 +setlocal cinkeys=0{,0},!^F,o,O,0[,0],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,macro + +" 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],0(,0) + +setlocal indentexpr=GetRustIndent(v:lnum) + +let b:undo_indent = "setlocal cindent< cinoptions< cinkeys< cinwords< lisp< autoindent< indentkeys< indentexpr<" + +" Only define the function once. +if exists("*GetRustIndent") + finish +endif + +" vint: -ProhibitAbbreviationOption +let s:save_cpo = &cpo +set cpo&mnv +" vint: +ProhibitAbbreviationOption + +" 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 + + " A standalone '{', '}', or 'where' + let l:standalone_open = line =~# '\V\^\s\*{\s\*\$' + let l:standalone_close = line =~# '\V\^\s\*}\s\*\$' + let l:standalone_where = line =~# '\V\^\s\*where\s\*\$' + if l:standalone_open || l:standalone_close || l:standalone_where + let l:orig_line = line('.') + let l:orig_col = col('.') + let l:i = 0 + while 1 + " ToDo: we can search for more items than 'fn' and 'if'. + let [l:found_line, l:col, l:submatch] = + \ searchpos('\<\(fn\|if\)\>', 'bWp') + if l:found_line ==# 0 || !s:is_string_comment(l:found_line, l:col) + break + endif + let l:i += 1 + " Limit to 10 iterations as a failsafe against endless looping. + if l:i >= 10 + let l:found_line = 0 + break + endif + endwhile + call cursor(l:orig_line, l:orig_col) + if l:found_line !=# 0 + " Now we count the number of '{' and '}' in between the match + " locations and the current line (there is probably a better + " way to compute this). + let l:i = l:found_line + let l:search_line = strpart(getline(l:i), l:col - 1) + let l:opens = 0 + let l:closes = 0 + while l:i < a:lnum + let l:search_line2 = substitute(l:search_line, '\V{', '', 'g') + let l:opens += strlen(l:search_line) - strlen(l:search_line2) + let l:search_line3 = substitute(l:search_line2, '\V}', '', 'g') + let l:closes += strlen(l:search_line2) - strlen(l:search_line3) + let l:i += 1 + let l:search_line = getline(l:i) + endwhile + if l:standalone_open || l:standalone_where + if l:opens ==# l:closes + return indent(l:found_line) + endif + else + " Expect to find just one more close than an open + if l:opens ==# l:closes + 1 + return indent(l:found_line) + endif + endif + endif + endif + + " A standalone 'where' adds a shift. + let l:standalone_prevline_where = prevline =~# '\V\^\s\*where\s\*\$' + if l:standalone_prevline_where + return indent(prevlinenum) + shiftwidth() + endif + + " Handle where clauses nicely: subsequent values should line up nicely. + if prevline[len(prevline) - 1] ==# "," + \ && prevline =~# '^\s*where\s' + return indent(prevlinenum) + 6 + endif + + let l:last_prevline_character = prevline[len(prevline) - 1] + + " A line that ends with '.<expr>;' is probably an end of a long list + " of method operations. + if prevline =~# '\V\^\s\*.' && l:last_prevline_character ==# ';' + call cursor(a:lnum - 1, 1) + let l:scope_start = searchpair('{\|(', '', '}\|)', 'nbW', + \ 's:is_string_comment(line("."), col("."))') + if l:scope_start != 0 && l:scope_start < a:lnum + return indent(l:scope_start) + shiftwidth() + endif + endif + + " Prevent cindent from becoming confused when pairing square brackets, as + " in + " + " let arr = [[u8; 4]; 2] = [ + " [0; 4], + " [1, 3, 5, 9], + " ]; + " | ← indentation placed here + " + " for which it calculates too much indentation in the line following the + " close of the array. + if prevline =~# '^\s*\]' && l:last_prevline_character ==# ';' + \ && line !~# '^\s*}' + return indent(prevlinenum) + endif + + if l:last_prevline_character ==# "," + \ && 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 + + " Fall back on cindent, which does it mostly right + return cindent(a:lnum) +endfunction + +" vint: -ProhibitAbbreviationOption +let &cpo = s:save_cpo +unlet s:save_cpo +" vint: +ProhibitAbbreviationOption + +" mnv: set et sw=4 sts=4 ts=8: |