" File: explainpat.vim
" Created: 2011 Nov 02
-" Last Change: 2012 Dec 19
-" Rev Days: 3
+" Last Change: 2017 Dec 15
+" Version: 0.9
" Author: Andy Wokula <anwoku@yahoo.de>
" License: Vim License, see :h license
-" Version: 0.1
" Implements :ExplainPattern [pattern]
+" History: "{{{
+" 2013 Jun 21 AND/OR text is confusing, removed
+" 2013 Apr 20 ...
+"}}}
+
" TODO {{{
+" - add something like "(empty) ... match everywhere" ... example: '\v(&&|str)'
+" Pattern: \v(&&|str)
+" Magic Pattern: \(\&\&\|str\)
+" \( start of first capturing group
+" | (empty) match everywhere
+" | \& AND
+" | (empty) match everywhere
+" | \& AND
+" | (empty) match everywhere
+" | \| OR
+" | str literal string (3 atom(s))
+" \) end of group
" - more testing, completeness check
-" - detailed collections
-" - \z
+" ? detailed collections
" ? literal string: also print the unescaped magic items
" ? literal string: show leading/trailing spaces
-" + start of "first" capturing group, start of 2nd ...
-" + `\|' should get less indent than the branches, do we need to create an
-" AST? ! no, keep it straight forward
-" + \%[...]
-" + \{, \{-
+"
"}}}
" Init Folklore {{{
let g:explainpat#loaded = 1
"}}}
-func! explainpat#ExplainPattern(cmd_arg) "{{{
+func! explainpat#ExplainPattern(cmd_arg, ...) "{{{
+ " {a:1} alternative help printer object (caution, no sanity check)
+ " (for test running)
if a:cmd_arg == ""
" let pattern_str = nwo#vis#Get()
echo "(usage) :ExplainPattern [{register} | {pattern}]"
echo printf('Magic Pattern: %s', magicpat)
endif
- " hmm, we need state for \%[ ... ]
+ " we need state:
+ " set flag when in `\%[ ... ]' (optionally matched atoms):
let s:in_opt_atoms = 0
+ " counter for `\(':
let s:capture_group_nr = 0
+ " >=1 at pos 0 or after '\|', '\&', '\(', '\%(' or '\n'; else 0 or less:
+ let s:at_begin_of_pat = 1
- let hulit = s:NewHelpPrinter()
+ let hulit = a:0>=1 && type(a:1)==s:DICT ? a:1 : explainpat#NewHelpPrinter()
call hulit.AddIndent(' ')
- let bull = s:NewTokenBiter(magicpat, '')
+ let bull = s:NewTokenBiter(magicpat)
while !bull.AtEnd()
let item = bull.Bite(s:magic_item_pattern)
if item != ''
call hulit.Print(item, Doc)
elseif type(Doc) == s:FUNCREF
call call(Doc, [bull, hulit, item])
+ elseif type(Doc) == s:LIST
+ call call(Doc[0], [bull, hulit, item, Doc[1]])
endif
+ let s:at_begin_of_pat -= 1
else
echoerr printf('ExplainPattern: cannot parse "%s"', bull.Rest())
break
let s:STRING = type("")
let s:DICT = type({})
let s:FUNCREF = type(function("tr"))
+let s:LIST = type([])
" }}}
-let s:magic_item_pattern = '\C^\%(\\\%(@<.\|%\%([dxouU[(^$V#]\|[<>]\=\%(''.\)\=\)\|z[1-9se(]\|{\|@[>=!]\|_[[^$.]\=\|.\)\|.\)'
+let s:magic_item_pattern = '\C^\%(\\\%(%#=\|%[dxouU[(^$V#<>]\=\|z[1-9se(]\|@[>=!]\=\|_[[^$.]\=\|.\)\|.\)'
let s:doc = {} " {{{
" this is all the help data ...
func! s:DocOrBranch(bull, hulit, item) "{{{
call a:hulit.RemIndent()
- call a:hulit.Print(a:item, "OR branch")
+ call a:hulit.Print(a:item, "OR")
call a:hulit.AddIndent(' ')
+ let s:at_begin_of_pat = 2
endfunc "}}}
let s:doc['\|'] = function("s:DocOrBranch")
-let s:doc['\&'] = "AND branch"
+
+func! s:DocBeginOfPat(bull, hulit, item, msg) "{{{
+ call a:hulit.Print(a:item, a:msg)
+ let s:at_begin_of_pat = 2
+endfunc "}}}
+
+let s:doc['\&'] = [function("s:DocBeginOfPat"), "AND"]
let s:ord = split('n first second third fourth fifth sixth seventh eighth ninth')
func! s:DocGroupStart(bull, hulit, item) "{{{
if a:item == '\%('
call a:hulit.Print(a:item, "start of non-capturing group")
- else " a:item == '\('
+ elseif a:item == '\('
let s:capture_group_nr += 1
call a:hulit.Print(a:item, printf("start of %s capturing group", get(s:ord, s:capture_group_nr, '(invalid)')))
+ else " a:item == '\z('
+ call a:hulit.Print(a:item, 'start of "external" group (only usable in :syn-region)')
endif
call a:hulit.AddIndent('| ', ' ')
+ let s:at_begin_of_pat = 2
endfunc "}}}
func! s:DocGroupEnd(bull, hulit, item) "{{{
call a:hulit.RemIndent(2)
let s:doc['\('] = function("s:DocGroupStart")
let s:doc['\%('] = function("s:DocGroupStart")
let s:doc['\)'] = function("s:DocGroupEnd")
+" let s:doc['\z('] = "only in syntax scripts"
+let s:doc['\z('] = function("s:DocGroupStart")
+
+func! s:DocStar(bull, hulit, item) "{{{
+ if s:at_begin_of_pat >= 1
+ " call a:hulit.Print(a:item, "(at begin of pattern) literal `*'")
+ call a:hulit.AddLiteral(a:item)
+ else
+ call a:hulit.Print(a:item, "(multi) zero or more of the preceding atom")
+ endif
+endfunc "}}}
+
+" let s:doc['*'] = "(multi) zero or more of the preceding atom"
+let s:doc['*'] = function("s:DocStar")
-let s:doc['\z('] = "only in syntax scripts"
-let s:doc['*'] = "(multi) zero or more of the preceding atom"
let s:doc['\+'] = "(multi) one or more of the preceding atom"
let s:doc['\='] = "(multi) zero or one of the preceding atom"
let s:doc['\?'] = "(multi) zero or one of the preceding atom"
" let s:doc['\{-'] = "(multi) N to M, non-greedy"
func! s:DocBraceMulti(bull, hulit, item) "{{{
- let rest = a:bull.Bite('^-\=\d*\%(,\d*\)\=}')
+ let rest = a:bull.Bite('^-\=\d*\%(,\d*\)\=\\\=}')
if rest != ""
if rest == '-}'
call a:hulit.Print(a:item. rest, "non-greedy version of `*'")
call a:hulit.Print(a:item. rest, "(multi) N to M, greedy")
endif
else
- echoerr printf('ExplainPattern: cannot parse %s', a:item. a:bull.Rest())
+ call a:hulit.Print(a:item, "(invalid) incomplete `\\{...}' item")
endif
endfunc "}}}
let s:doc['\@>'] = "(multi) match preceding atom like a full pattern"
let s:doc['\@='] = "(assertion) require match for preceding atom"
let s:doc['\@!'] = "(assertion) forbid match for preceding atom"
-let s:doc['\@<='] = "(assertion) require match for preceding atom to the left"
-let s:doc['\@<!'] = "(assertion) forbid match for preceding atom to the left"
-let s:doc['^'] = "(assertion) require match at start of line"
+
+func! s:DocBefore(bull, hulit, item) "{{{
+ let rest = a:bull.Bite('^\d*\%[<[=!]]')
+ if rest == "<="
+ call a:hulit.Print(a:item.rest, "(assertion) require match for preceding atom to the left")
+ elseif rest == "<!"
+ call a:hulit.Print(a:item.rest, "(assertion) forbid match for preceding atom to the left")
+ elseif rest =~ '^\d\+<='
+ call a:hulit.Print(a:item.rest, printf("(assertion) like `\\@<=', looking back at most %s bytes (since Vim 7.3.1037)", s:SillyCheck(matchstr(rest, '\d\+'))))
+ elseif rest =~ '^\d\+<!'
+ call a:hulit.Print(a:item.rest, printf("(assertion) like `\\@<!', looking back at most %s bytes (since Vim 7.3.1037)", s:SillyCheck(matchstr(rest, '\d\+'))))
+ else
+ call a:hulit.Print(a:item.rest, "(invalid) incomplete item")
+ endif
+endfunc "}}}
+
+let s:doc['\@'] = function("s:DocBefore")
+
+func! s:DocCircumFlex(bull, hulit, item) "{{{
+ if s:at_begin_of_pat >= 1
+ call a:hulit.Print(a:item, "(assertion) require match at start of line")
+ " after `^' is not at begin of pattern ... handle special case `^*' here:
+ if a:bull.Bite('^\*') == "*"
+ call a:hulit.AddLiteral("*")
+ endif
+ else
+ " call a:hulit.Print(a:item, "(not at begin of pattern) literal `^'")
+ call a:hulit.AddLiteral(a:item)
+ endif
+endfunc "}}}
+
+" let s:doc['^'] = "(assertion) require match at start of line"
+let s:doc['^'] = function("s:DocCircumFlex")
+
let s:doc['\_^'] = "(assertion) like `^', allowed anywhere in the pattern"
-let s:doc['$'] = "(assertion) require match at end of line"
+
+func! s:DocDollar(bull, hulit, item) "{{{
+ if a:bull.Rest() =~ '^$\|^\\[&|)n]'
+ call a:hulit.Print(a:item, "(assertion) require match at end of line")
+ else
+ call a:hulit.AddLiteral(a:item)
+ endif
+endfunc "}}}
+
+" let s:doc['$'] = "(assertion) require match at end of line"
+let s:doc['$'] = function("s:DocDollar")
+
let s:doc['\_$'] = "(assertion) like `$', allowed anywhere in the pattern"
let s:doc['.'] = "match any character"
let s:doc['\_.'] = "match any character or newline"
let cclass_doc = get(s:doc, '\'. cclass, '(invalid character class)')
call a:hulit.Print(a:item. cclass, printf('%s or end-of-line', cclass_doc))
else
- echoerr printf('ExplainPattern: cannot parse %s', a:item. matchstr(a:bull.Rest(), '.'))
+ call a:hulit.Print(a:item, "(invalid) `\\_' should be followed by a letter or `[...]'")
+ " echoerr printf('ExplainPattern: cannot parse %s', a:item. matchstr(a:bull.Rest(), '.'))
endif
endfunc "}}}
let s:doc['\%V'] = "(assertion) match within the Visual area"
let s:doc['\%#'] = "(assertion) match with cursor position"
+func! s:DocRegexEngine(bull, hulit, item) "{{{
+ let engine = a:bull.Bite('^[012]')
+ if engine == "0"
+ call a:hulit.Print(a:item.engine, 'Force automatic selection of the regexp engine (since v7.3.970).')
+ elseif engine == "1"
+ call a:hulit.Print(a:item.engine, 'Force using the old engine (since v7.3.970).')
+ elseif engine == "2"
+ call a:hulit.Print(a:item.engine, 'Force using the NFA engine (since v7.3.970).')
+ else
+ call a:hulit.Print(a:item, '(invalid) \%#= can only be followed by 0, 1, or 2')
+ endif
+endfunc "}}}
+
+let s:doc['\%#='] = function("s:DocRegexEngine")
+
" \%'m \%<'m \%>'m
" \%23l \%<23l \%>23l
" \%23c \%<23c \%>23c
" \%23v \%<23v \%>23v
" backslash percent at/before/after
func! s:DocBspercAt(bull, hulit, item) "{{{
- let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)')
+ let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)\C')
if rest[0] == "'"
- call a:hulit.Print("(assertion) match with position of mark ". rest[1])
+ call a:hulit.Print(a:item.rest, "(assertion) match with position of mark ". rest[1])
else
let number = rest[:-2]
let type = rest[-1:]
- if type == "l"
- call a:hulit.Print("match in line ". number)
- elseif type == "c"
- call a:hulit.Print("match in column ". number)
- elseif type == "v"
- call a:hulit.Print("match in virtual column ". number)
+ if type ==# "l"
+ call a:hulit.Print(a:item.rest, "match in line ". number)
+ elseif type ==# "c"
+ call a:hulit.Print(a:item.rest, "match in column ". number)
+ elseif type ==# "v"
+ call a:hulit.Print(a:item.rest, "match in virtual column ". number)
+ else
+ call a:hulit.Print(a:item.rest, "(invalid) incomplete `\\%' item")
+ " echoerr printf('ExplainPattern: incomplete item %s', a:item. rest)
endif
endif
endfunc "}}}
func! s:DocBspercBefore(bull, hulit, item) "{{{
- let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)')
+ let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)\C')
if rest[0] == "'"
- call a:hulit.Print("(assertion) match before position of mark ". rest[1])
+ call a:hulit.Print(a:item.rest, "(assertion) match before position of mark ". rest[1])
else
let number = rest[:-2]
let type = rest[-1:]
- if type == "l"
- call a:hulit.Print("match above line ". number)
- elseif type == "c"
- call a:hulit.Print("match before column ". number)
- elseif type == "v"
- call a:hulit.Print("match before virtual column ". number)
+ if type ==# "l"
+ call a:hulit.Print(a:item.rest, printf("match above line %d (towards start of buffer)", number))
+ elseif type ==# "c"
+ call a:hulit.Print(a:item.rest, "match before column ". number)
+ elseif type ==# "v"
+ call a:hulit.Print(a:item.rest, "match before virtual column ". number)
+ else
+ call a:hulit.Print(a:item.rest, "(invalid) incomplete `\\%<' item")
+ " echoerr printf('ExplainPattern: incomplete item %s', a:item. rest)
endif
endif
endfunc "}}}
func! s:DocBspercAfter(bull, hulit, item) "{{{
- let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)')
+ let rest = a:bull.Bite('^\%(''.\|\d\+[lvc]\)\C')
if rest[0] == "'"
- call a:hulit.Print("(assertion) match after position of mark ". rest[1])
+ call a:hulit.Print(a:item.rest, "(assertion) match after position of mark ". rest[1])
else
let number = rest[:-2]
let type = rest[-1:]
- if type == "l"
- call a:hulit.Print("match below line ". number)
- elseif type == "c"
- call a:hulit.Print("match after column ". number)
- elseif type == "v"
- call a:hulit.Print("match after virtual column ". number)
+ if type ==# "l"
+ call a:hulit.Print(a:item.rest, printf("match below line %d (towards end of buffer)", number))
+ elseif type ==# "c"
+ call a:hulit.Print(a:item.rest, "match after column ". number)
+ elseif type ==# "v"
+ call a:hulit.Print(a:item.rest, "match after virtual column ". number)
+ else
+ call a:hulit.Print(a:item.rest, "(invalid) incomplete `\\%>' item")
+ " echoerr printf('ExplainPattern: incomplete item %s', a:item. rest)
endif
endif
endfunc "}}}
let s:doc['\t'] = "match <Tab>"
let s:doc['\r'] = "match <CR>"
let s:doc['\b'] = "match CTRL-H"
-let s:doc['\n'] = "match a newline"
+let s:doc['\n'] = [function("s:DocBeginOfPat"), "match a newline"]
let s:doc['~'] = "match the last given substitute string"
let s:doc['\1'] = "match first captured string"
let s:doc['\2'] = "match second captured string"
let s:doc['\8'] = "match eighth captured string"
let s:doc['\9'] = "match ninth captured string"
-" \z1
-" \z2
-" \z9
+let s:doc['\z1'] = 'match same string matched by first "external" group'
+let s:doc['\z2'] = 'match same string matched by second "external" group'
+let s:doc['\z3'] = 'match same string matched by third "external" group'
+let s:doc['\z4'] = 'match same string matched by fourth "external" group '
+let s:doc['\z5'] = 'match same string matched by fifth "external" group'
+let s:doc['\z6'] = 'match same string matched by sixth "external" group'
+let s:doc['\z7'] = 'match same string matched by seventh "external" group'
+let s:doc['\z8'] = 'match same string matched by eighth "external" group'
+let s:doc['\z9'] = 'match same string matched by ninth "external" group'
" from MakeMagic()
" skip the rest of a collection
-let s:coll_skip_pat = '^\^\=]\=\%(\%(\\[\^\]\-\\bertn]\|\[:\w\+:]\|[^\]]\)\@>\)*]'
+let s:coll_skip_pat = '^\^\=]\=\%(\%(\\[\^\]\-\\bertn]\|\[:\w\+:]\|\[=.=]\|\[\..\.]\|[^\]]\)\@>\)*]'
func! s:DocCollection(bull, hulit, item) "{{{
let collstr = a:bull.Bite(s:coll_skip_pat)
- call a:hulit.Print(a:item. collstr, 'collection'. (a:item=='\_[' ? ' with end-of-line added' : ''))
+ if collstr == "" || collstr == "]"
+ call a:hulit.AddLiteral('['. collstr)
+ else
+ let inverse = collstr =~ '^\^'
+ let with_nl = a:item == '\_['
+ let descr = inverse ? printf('collection not matching [%s', collstr[1:]) : 'collection'
+ let descr_nl = printf("%s%s", (inverse && with_nl ? ', but' : ''), (with_nl ? ' with end-of-line added' : ''))
+ call a:hulit.Print(a:item. collstr, descr. descr_nl)
+ endif
endfunc "}}}
let s:doc['['] = function("s:DocCollection")
let s:doc['\%['] = function("s:DocOptAtoms")
let s:doc[']'] = function("s:DocOptAtoms")
-let s:doc['\c'] = "ignore case while matching the pattern"
-let s:doc['\C'] = "match case while matching the pattern"
-let s:doc['\Z'] = "ignore composing characters in the pattern"
+func! s:DocAnywhere(bull, hulit, item, msg) "{{{
+ call a:hulit.Print(a:item, a:msg)
+ " keep state:
+ let s:at_begin_of_pat += 1
+endfunc "}}}
+
+let s:doc['\c'] = [function("s:DocAnywhere"), "ignore case while matching the pattern"]
+let s:doc['\C'] = [function("s:DocAnywhere"), "match case while matching the pattern"]
+let s:doc['\Z'] = [function("s:DocAnywhere"), "ignore composing characters in the pattern"]
" \%d 123
" \%x 2a
func! s:DocBspercDecimal(bull, hulit, item) "{{{
let number = a:bull.Bite('^\d\{,3}')
- call a:hulit.Print(a:item. number, "match character specified by decimal number ". number)
+ let char = strtrans(nr2char(str2nr(number)))
+ call a:hulit.Print(a:item. number, printf("match character specified by decimal number %s (%s)", number, char))
endfunc "}}}
func! s:DocBspercHexTwo(bull, hulit, item) "{{{
let number = a:bull.Bite('^\x\{,2}')
- call a:hulit.Print(a:item. number, "match character specified with hex number 0x". number)
+ let char = strtrans(nr2char(str2nr(number,16)))
+ call a:hulit.Print(a:item. number, printf("match character specified with hex number 0x%s (%s)", number, char))
endfunc "}}}
func! s:DocBspercOctal(bull, hulit, item) "{{{
let number = a:bull.Bite('^\o\{,4}')
- call a:hulit.Print(a:item. number, "match character specified with octal number 0". substitute(number, '^0*', '', ''))
+ let char = strtrans(nr2char(str2nr(number,8)))
+ call a:hulit.Print(a:item. number, printf("match character specified with octal number 0%s (%s)", substitute(number, '^0*', '', ''), char))
endfunc "}}}
func! s:DocBspercHexFour(bull, hulit, item) "{{{
let number = a:bull.Bite('^\x\{,4}')
- call a:hulit.Print(a:item. number, "match character specified with hex number 0x". number)
+ let char = has("multi_byte_encoding") ? ' ('. strtrans(nr2char(str2nr(number,16))).')' : ''
+ call a:hulit.Print(a:item. number, printf("match character specified with hex number 0x%s%s", number, char))
endfunc "}}}
func! s:DocBspercHexEight(bull, hulit, item) "{{{
let number = a:bull.Bite('^\x\{,8}')
- call a:hulit.Print(a:item. number, "match character specified with hex number 0x". number)
+ let char = has("multi_byte_encoding") ? ' ('. strtrans(nr2char(str2nr(number,16))).')' : ''
+ call a:hulit.Print(a:item. number, printf("match character specified with hex number 0x%s%s", number, char))
endfunc "}}}
let s:doc['\%d'] = function("s:DocBspercDecimal") " 123
" \V
"}}}
-func! s:NewHelpPrinter() "{{{
+" {{{
+func! s:SillyCheck(digits) "{{{
+ return strlen(a:digits) < 10 ? a:digits : '{silly large number}'
+endfunc "}}}
+" }}}
+
+func! explainpat#NewHelpPrinter() "{{{
let obj = {}
let obj.literals = ''
let obj.indents = []
if self.literals =~ '\\'
let self.literals = substitute(self.literals, '\\\(.\)', '\1', 'g')
endif
- let so = self.literals =~ '[^ ]' ? '' : ', spaces only'
- echon " (". strchars(self.literals). " atom(s)". so.")"
+ let spconly = self.literals =~ '[^ ]' ? '' : ', spaces only'
+ let nlit = strchars(self.literals)
+ echon " (". nlit. (nlit==1 ? " atom" : " atoms"). spconly.")"
endif
echohl None
let self.literals = ''
return obj
endfunc "}}}
-func! s:NewTokenBiter(str, ...) "{{{
+func! s:NewTokenBiter(str) "{{{
" {str} string to eat pieces from
- " {a:1} pattern to skip separators
- let whitepat = a:0>=1 ? a:1 : '^\s*'
- let obj = {'str': a:str, 'whitepat': whitepat}
+ let obj = {'str': a:str}
" consume piece from start of input matching {pat}
func! obj.Bite(pat) "{{{
" {pat} should start with '^'
- let skip = matchend(self.str, self.whitepat)
- let bite = matchstr(self.str, a:pat, skip)
- let self.str = strpart(self.str, matchend(self.str, self.whitepat, skip + strlen(bite)))
+ let bite = matchstr(self.str, a:pat)
+ let self.str = strpart(self.str, strlen(bite))
return bite
endfunc "}}}
- " get the unparsed rest of input
+ " get the unparsed rest of input (not consuming)
func! obj.Rest() "{{{
return self.str
endfunc "}}}