321 lines
9.7 KiB
VimL
321 lines
9.7 KiB
VimL
vim9script
|
|
|
|
# MetaPost indent file
|
|
# Language: MetaPost
|
|
# Maintainer: Nicola Vitacolonna <nvitacolonna@gmail.com>
|
|
# Former Maintainers: Eugene Minkovskii <emin@mccme.ru>
|
|
# Latest Revision: 2022 Aug 12
|
|
|
|
if exists("b:did_indent")
|
|
finish
|
|
endif
|
|
|
|
b:did_indent = 1
|
|
|
|
setlocal indentexpr=g:MetaPostIndent()
|
|
setlocal indentkeys+==end,=else,=fi,=fill,0),0]
|
|
setlocal nolisp
|
|
setlocal nosmartindent
|
|
|
|
b:undo_indent = "setl indentexpr< indentkeys< lisp< smartindent<"
|
|
|
|
# Regexps {{{
|
|
# Expressions starting indented blocks
|
|
const MP_OPEN_TAG = [
|
|
'\<if\>',
|
|
'\<else\%[if]\>',
|
|
'\<for\%(\|ever\|suffixes\)\>',
|
|
'\<begingroup\>',
|
|
'\<\%(\|var\|primary\|secondary\|tertiary\)def\>',
|
|
'^\s*\<begin\%(fig\|graph\|glyph\|char\|logochar\)\>',
|
|
'[([{]',
|
|
]->extend(get(g:, "mp_open_tag", []))->join('\|')
|
|
|
|
# Expressions ending indented blocks
|
|
const MP_CLOSE_TAG = [
|
|
'\<fi\>',
|
|
'\<else\%[if]\>',
|
|
'\<end\%(\|for\|group\|def\|fig\|char\|glyph\|graph\)\>',
|
|
'[)\]}]'
|
|
]->extend(get(g:, "mp_close_tag", []))->join('\|')
|
|
|
|
# Statements that may span multiple lines and are ended by a semicolon. To
|
|
# keep this list short, statements that are unlikely to be very long or are
|
|
# not very common (e.g., keywords like `interim` or `showtoken`) are not
|
|
# included.
|
|
#
|
|
# The regex for assignments and equations (the last branch) is tricky, because
|
|
# it must not match things like `for i :=`, `if a=b`, `def...=`, etc... It is
|
|
# not perfect, but it works reasonably well.
|
|
const MP_STATEMENT = [
|
|
'\<\%(\|un\|cut\)draw\%(dot\)\=\>',
|
|
'\<\%(\|un\)fill\%[draw]\>',
|
|
'\<draw\%(dbl\)\=arrow\>',
|
|
'\<clip\>',
|
|
'\<addto\>',
|
|
'\<save\>',
|
|
'\<setbounds\>',
|
|
'\<message\>',
|
|
'\<errmessage\>',
|
|
'\<errhelp\>',
|
|
'\<fontmapline\>',
|
|
'\<pickup\>',
|
|
'\<show\>',
|
|
'\<special\>',
|
|
'\<write\>',
|
|
'\%(^\|;\)\%([^;=]*\%(' .. MP_OPEN_TAG .. '\)\)\@!.\{-}:\==',
|
|
]->join('\|')
|
|
|
|
# A line ends with zero or more spaces, possibly followed by a comment.
|
|
const EOL = '\s*\%($\|%\)'
|
|
# }}}
|
|
|
|
# Auxiliary functions {{{
|
|
# Returns true if (0-based) position immediately preceding `pos` in `line` is
|
|
# inside a string or a comment; returns false otherwise.
|
|
|
|
# This is the function that is called more often when indenting, so it is
|
|
# critical that it is efficient. The method we use is significantly faster
|
|
# than using syntax attributes, and more general (it does not require
|
|
# syntax_items). It is also faster than using a single regex matching an even
|
|
# number of quotes. It helps that MetaPost strings cannot span more than one
|
|
# line and cannot contain escaped quotes.
|
|
def IsCommentOrString(line: string, pos: number): bool
|
|
var in_string = 0
|
|
var q = stridx(line, '"')
|
|
var c = stridx(line, '%')
|
|
|
|
while q >= 0 && q < pos
|
|
if c >= 0 && c < q
|
|
if in_string # Find next percent symbol
|
|
c = stridx(line, '%', q + 1)
|
|
else # Inside comment
|
|
return true
|
|
endif
|
|
endif
|
|
in_string = 1 - in_string
|
|
q = stridx(line, '"', q + 1) # Find next quote
|
|
endwhile
|
|
|
|
return in_string || (c >= 0 && c <= pos)
|
|
enddef
|
|
|
|
# Find the first non-comment non-blank line before the given line.
|
|
def PrevNonBlankNonComment(lnum: number): number
|
|
var nr = prevnonblank(lnum - 1)
|
|
while getline(nr) =~# '^\s*%'
|
|
nr = prevnonblank(nr - 1)
|
|
endwhile
|
|
return nr
|
|
enddef
|
|
|
|
# Returns true if the last tag appearing in the line is an open tag; returns
|
|
# false otherwise.
|
|
def LastTagIsOpen(line: string): bool
|
|
var o = LastValidMatchEnd(line, MP_OPEN_TAG, 0)
|
|
if o == - 1
|
|
return false
|
|
endif
|
|
return LastValidMatchEnd(line, MP_CLOSE_TAG, o) < 0
|
|
enddef
|
|
|
|
# A simple, efficient and quite effective heuristics is used to test whether
|
|
# a line should cause the next line to be indented: count the "opening tags"
|
|
# (if, for, def, ...) in the line, count the "closing tags" (endif, endfor,
|
|
# ...) in the line, and compute the difference. We call the result the
|
|
# "weight" of the line. If the weight is positive, then the next line should
|
|
# most likely be indented. Note that `else` and `elseif` are both opening and
|
|
# closing tags, so they "cancel out" in almost all cases, the only exception
|
|
# being a leading `else[if]`, which is counted as an opening tag, but not as
|
|
# a closing tag (so that, for instance, a line containing a single `else:`
|
|
# will have weight equal to one, not zero). We do not treat a trailing
|
|
# `else[if]` in any special way, because lines ending with an open tag are
|
|
# dealt with separately before this function is called (see MetaPostIndent()).
|
|
#
|
|
# Example:
|
|
#
|
|
# forsuffixes $=a,b: if x.$ = y.$ : draw else: fill fi
|
|
# % This line will be indented because |{forsuffixes,if,else}| > |{else,fi}| (3 > 2)
|
|
# endfor
|
|
def Weight(line: string): number
|
|
var o = 0
|
|
var i = ValidMatchEnd(line, MP_OPEN_TAG, 0)
|
|
while i > 0
|
|
o += 1
|
|
i = ValidMatchEnd(line, MP_OPEN_TAG, i)
|
|
endwhile
|
|
var c = 0
|
|
i = matchend(line, '^\s*\<else\%[if]\>') # Skip a leading else[if]
|
|
i = ValidMatchEnd(line, MP_CLOSE_TAG, i)
|
|
while i > 0
|
|
c += 1
|
|
i = ValidMatchEnd(line, MP_CLOSE_TAG, i)
|
|
endwhile
|
|
return o - c
|
|
enddef
|
|
|
|
# Similar to matchend(), but skips strings and comments.
|
|
# line: a String
|
|
def ValidMatchEnd(line: string, pat: string, start: number): number
|
|
var i = matchend(line, pat, start)
|
|
while i > 0 && IsCommentOrString(line, i)
|
|
i = matchend(line, pat, i)
|
|
endwhile
|
|
return i
|
|
enddef
|
|
|
|
# Like s:ValidMatchEnd(), but returns the end position of the last (i.e.,
|
|
# rightmost) match.
|
|
def LastValidMatchEnd(line: string, pat: string, start: number): number
|
|
var last_found = -1
|
|
var i = matchend(line, pat, start)
|
|
while i > 0
|
|
if !IsCommentOrString(line, i)
|
|
last_found = i
|
|
endif
|
|
i = matchend(line, pat, i)
|
|
endwhile
|
|
return last_found
|
|
enddef
|
|
|
|
def DecreaseIndentOnClosingTag(curr_indent: number): number
|
|
var cur_text = getline(v:lnum)
|
|
if cur_text =~# '^\s*\%(' .. MP_CLOSE_TAG .. '\)'
|
|
return max([curr_indent - shiftwidth(), 0])
|
|
endif
|
|
return curr_indent
|
|
enddef
|
|
# }}}
|
|
|
|
# Main function {{{
|
|
def g:MetaPostIndent(): number
|
|
# Do not touch indentation inside verbatimtex/btex.. etex blocks.
|
|
if synIDattr(synID(v:lnum, 1, 1), "name") =~# '^mpTeXinsert$\|^tex\|^Delimiter'
|
|
return -1
|
|
endif
|
|
|
|
# At the start of a MetaPost block inside ConTeXt, do not touch indentation
|
|
if synIDattr(synID(prevnonblank(v:lnum - 1), 1, 1), "name") == "contextBlockDelim"
|
|
return -1
|
|
endif
|
|
|
|
var lnum = PrevNonBlankNonComment(v:lnum)
|
|
|
|
# At the start of the file use zero indent.
|
|
if lnum == 0
|
|
return 0
|
|
endif
|
|
|
|
var prev_text = getline(lnum)
|
|
|
|
# Every rule of indentation in MetaPost is very subjective. We might get
|
|
# creative, but things get murky very soon (there are too many corner
|
|
# cases). So, we provide a means for the user to decide what to do when this
|
|
# script doesn't get it. We use a simple idea: use '%>', '%<', '%=', and
|
|
# '%!', to explicitly control indentation. The '<' and '>' symbols may be
|
|
# repeated many times (e.g., '%>>' will cause the next line to be indented
|
|
# twice).
|
|
#
|
|
# User-defined overrides take precedence over anything else.
|
|
var j = match(prev_text, '%[<>=!]')
|
|
if j > 0
|
|
var i = strlen(matchstr(prev_text, '%>\+', j)) - 1
|
|
if i > 0
|
|
return indent(lnum) + i * shiftwidth()
|
|
endif
|
|
|
|
i = strlen(matchstr(prev_text, '%<\+', j)) - 1
|
|
if i > 0
|
|
return max([indent(lnum) - i * shiftwidth(), 0])
|
|
endif
|
|
|
|
if match(prev_text, '%=', j) > -1
|
|
return indent(lnum)
|
|
endif
|
|
|
|
if match(prev_text, '%!', j) > -1
|
|
return -1
|
|
endif
|
|
endif
|
|
|
|
# If the reference line ends with an open tag, indent.
|
|
#
|
|
# Example:
|
|
#
|
|
# if c:
|
|
# 0
|
|
# else:
|
|
# 1
|
|
# fi if c2: % Note that this line has weight equal to zero.
|
|
# ... % This line will be indented
|
|
if LastTagIsOpen(prev_text)
|
|
return DecreaseIndentOnClosingTag(indent(lnum) + shiftwidth())
|
|
endif
|
|
|
|
# Lines with a positive weight are unbalanced and should likely be indented.
|
|
#
|
|
# Example:
|
|
#
|
|
# def f = enddef for i = 1 upto 5: if x[i] > 0: 1 else: 2 fi
|
|
# ... % This line will be indented (because of the unterminated `for`)
|
|
if Weight(prev_text) > 0
|
|
return DecreaseIndentOnClosingTag(indent(lnum) + shiftwidth())
|
|
endif
|
|
|
|
# Unterminated statements cause indentation to kick in.
|
|
#
|
|
# Example:
|
|
#
|
|
# draw unitsquare
|
|
# withcolor black; % This line is indented because of `draw`.
|
|
# x := a + b + c
|
|
# + d + e; % This line is indented because of `:=`.
|
|
#
|
|
var i = LastValidMatchEnd(prev_text, MP_STATEMENT, 0)
|
|
if i >= 0 # Does the line contain a statement?
|
|
if ValidMatchEnd(prev_text, ';', i) < 0 # Is the statement unterminated?
|
|
return indent(lnum) + shiftwidth()
|
|
else
|
|
return DecreaseIndentOnClosingTag(indent(lnum))
|
|
endif
|
|
endif
|
|
|
|
# Deal with the special case of a statement spanning multiple lines. If the
|
|
# current reference line L ends with a semicolon, search backwards for
|
|
# another semicolon or a statement keyword. If the latter is found first,
|
|
# its line is used as the reference line for indenting the current line
|
|
# instead of L.
|
|
#
|
|
# Example:
|
|
#
|
|
# if cond:
|
|
# draw if a: z0 else: z1 fi
|
|
# shifted S
|
|
# scaled T; % L
|
|
#
|
|
# for i = 1 upto 3: % <-- Current line: this gets the same indent as `draw ...`
|
|
#
|
|
# NOTE: we get here only if L does not contain a statement (among those
|
|
# listed in g:MP_STATEMENT).
|
|
if ValidMatchEnd(prev_text, ';' .. EOL, 0) >= 0 # L ends with a semicolon
|
|
var stm_lnum = PrevNonBlankNonComment(lnum)
|
|
while stm_lnum > 0
|
|
prev_text = getline(stm_lnum)
|
|
var sc_pos = LastValidMatchEnd(prev_text, ';', 0)
|
|
var stm_pos = ValidMatchEnd(prev_text, MP_STATEMENT, sc_pos)
|
|
if stm_pos > sc_pos
|
|
lnum = stm_lnum
|
|
break
|
|
elseif sc_pos > stm_pos
|
|
break
|
|
endif
|
|
stm_lnum = PrevNonBlankNonComment(stm_lnum)
|
|
endwhile
|
|
endif
|
|
|
|
return DecreaseIndentOnClosingTag(indent(lnum))
|
|
enddef
|
|
# }}}
|
|
|
|
# vim: sw=2 fdm=marker
|