Add fallback for when Vim was not compiled with searchpairpos

Author: axvr

indent/clojure.vim

@@ -15,15 +15,13 @@ let b:did_indent = 1
 let s:save_cpo = &cpoptions
 set cpoptions&vim
 
-let b:undo_indent = 'setlocal autoindent< smartindent< expandtab< softtabstop< shiftwidth< indentexpr< indentkeys<'
+let b:undo_indent = 'setlocal autoindent< smartindent< expandtab< softtabstop< shiftwidth< indentexpr< indentkeys< lisp<'
 
-setlocal noautoindent nosmartindent
+setlocal noautoindent nosmartindent nolisp
 setlocal softtabstop=2 shiftwidth=2 expandtab
 setlocal indentkeys=!,o,O
 
-" TODO: ignore 'lisp' and 'lispwords' options (actually, turn them off?)
-" TODO: Optional Vim9script implementations of hotspot/bottleneck functions?
-" FIXME: fallback case when syntax highlighting is disabled.
+" TODO: Write an optional Vim9 script version for better performance?
 
 function! s:GetSynIdName(line, col)
 	return synIDattr(synID(a:line, a:col, 0), 'name')
@@ -37,11 +35,11 @@ function! s:IgnoredRegion()
 	return s:SyntaxMatch('\(string\|regex\|comment\|character\)', line('.'), col('.'))
 endfunction
 
-function! s:NotAStringDelimiter()
+function! s:NotStringDelimiter()
 	return ! s:SyntaxMatch('stringdelimiter', line('.'), col('.'))
 endfunction
 
-function! s:NotARegexpDelimiter()
+function! s:NotRegexpDelimiter()
 	return ! s:SyntaxMatch('regexpdelimiter', line('.'), col('.'))
 endfunction
 
@@ -54,53 +52,53 @@ function! s:ShouldAlignMultiLineStrings()
 endfunction
 
 " Wrapper around "searchpairpos" that will automatically set "s:best_match" to
-" the closest pair match and continuously optimise the "stopline" value for
-" later searches.  This results in a significant performance gain by reducing
-" the number of syntax lookups that need to take place.
-function! s:CheckPair(name, start, end, skipfn)
+" the closest pair match and optimises the "stopline" value for later
+" searches.  This results in a significant performance gain by reducing the
+" number of syntax lookups that need to take place.
+function! s:CheckPair(name, start, end, SkipFn)
 	let prevln = s:best_match[1][0]
-	let pos = searchpairpos(a:start, '', a:end, 'bznW', a:skipfn, prevln)
+	let pos = searchpairpos(a:start, '', a:end, 'bznW', a:SkipFn, prevln)
 	if prevln < pos[0] || (prevln == pos[0] && s:best_match[1][1] < pos[1])
 		let s:best_match = [a:name, pos]
 	endif
 endfunction
 
 function! s:GetClojureIndent()
-	let lnum = v:lnum
-
 	" Move cursor to the first column of the line we want to indent.
-	cursor(lnum, 0)
+	call cursor(v:lnum, 0)
 
 	let s:best_match = ['top', [0, 0]]
 
-	call s:CheckPair('lst',  '(',  ')', function('<SID>IgnoredRegion'))
-	call s:CheckPair('map',  '{',  '}', function('<SID>IgnoredRegion'))
-	call s:CheckPair('vec', '\[', '\]', function('<SID>IgnoredRegion'))
+	let IgnoredRegionFn = function('<SID>IgnoredRegion')
+
+	call s:CheckPair('lst',  '(',  ')', IgnoredRegionFn)
+	call s:CheckPair('map',  '{',  '}', IgnoredRegionFn)
+	call s:CheckPair('vec', '\[', '\]', IgnoredRegionFn)
 
-	let synname = s:GetSynIdName(lnum, col('.'))
+	let synname = s:GetSynIdName(v:lnum, col('.'))
 	if synname =~? 'string'
-		call s:CheckPair('str', '"', '"', function('<SID>NotAStringDelimiter'))
+		call s:CheckPair('str', '"', '"', function('<SID>NotStringDelimiter'))
 	elseif synname =~? 'regex'
-		call s:CheckPair('reg', '#\zs"', '"', function('<SID>NotARegexpDelimiter'))
+		call s:CheckPair('reg', '#\zs"', '"', function('<SID>NotRegexpDelimiter'))
 	endif
 
 	" Find closest matching higher form.
 	let [formtype, coord] = s:best_match
-	" echom 'Match' formtype coord
 
 	if formtype == 'top'
 		" At the top level, no indent.
 		return 0
 	elseif formtype == 'lst'
 		" Inside a list.
 		" TODO Begin analysis and apply rules!
-		" echom getline(coord[0], lnum - 1)
+		" echom getline(coord[0], v:lnum - 1)
 		return coord[1] + 1
 	elseif formtype == 'vec' || formtype == 'map'
 		" Inside a vector, map or set.
 		return coord[1]
 	elseif formtype == 'str'
 		" Inside a string.
+		" TODO: maintain string and regex indentation when `=` is pressed.
 		return coord[1] - (s:ShouldAlignMultiLineStrings() ? 0 : 1)
 	elseif formtype == 'reg'
 		" Inside a regex.
@@ -110,16 +108,13 @@ function! s:GetClojureIndent()
 	return 2
 endfunction
 
-
-setlocal indentexpr=s:GetClojureIndent()
-
-
-" TODO: if exists("*searchpairpos")
-" In case we have searchpairpos not available we fall back to normal lisp
-" indenting.
-"setlocal indentexpr=
-"setlocal lisp
-"let b:undo_indent .= '| setlocal lisp<'
+if exists("*searchpairpos")
+	setlocal indentexpr=s:GetClojureIndent()
+else
+	" If searchpairpos is not available, fallback to normal lisp
+	" indenting.
+	setlocal lisp indentexpr=
+endif
 
 let &cpoptions = s:save_cpo
 unlet! s:save_cpo