diff options
Diffstat (limited to 'tex/context/base/util-str.lua')
| -rw-r--r-- | tex/context/base/util-str.lua | 58 |
1 files changed, 38 insertions, 20 deletions
diff --git a/tex/context/base/util-str.lua b/tex/context/base/util-str.lua index adcbf1654..13d9b8a63 100644 --- a/tex/context/base/util-str.lua +++ b/tex/context/base/util-str.lua @@ -10,7 +10,7 @@ utilities = utilities or {} utilities.strings = utilities.strings or { } local strings = utilities.strings -local find, gsub, rep = string.find, string.gsub, string.rep +local gsub, rep = string.gsub, string.rep local Cs, C, Cp, P, Carg = lpeg.Cs, lpeg.C, lpeg.Cp, lpeg.P, lpeg.Carg local patterns, lpegmatch = lpeg.patterns, lpeg.match @@ -33,27 +33,45 @@ end -- The following functions might end up in another namespace. ---~ function strings.tabtospace(str,tab) ---~ -- we don't handle embedded newlines ---~ while true do ---~ local s = find(str,"\t") ---~ if s then ---~ if not tab then tab = 7 end -- only when found ---~ local d = tab-(s-1) % tab ---~ if d > 0 then ---~ str = gsub(str,"\t",rep(" ",d),1) ---~ else ---~ str = gsub(str,"\t","",1) ---~ end ---~ else ---~ break ---~ end ---~ end ---~ return str ---~ end +local repeaters = { } -- watch how we also moved the -1 in depth-1 to the creator + +function strings.newrepeater(str,offset) + offset = offset or 0 + local s = repeaters[str] + if not s then + s = { } + repeaters[str] = s + end + local t = s[offset] + if t then + return t + end + t = { } + setmetatable(t, { + __index = function(t,k) + if not k then + return "" + end + local n = k + offset + local s = n > 0 and rep(str,n) or "" + t[k] = s + return s + end + } ) + s[offset] = t + return t +end + +--~ local dashes = strings.newrepeater("--",-1) + +--~ print(dashes[2]) +--~ print(dashes[3]) +--~ print(dashes[1]) local extra, tab, start = 0, 0, 4, 0 +local nspaces = strings.newrepeater(" ") + local pattern = Carg(1) / function(t) extra, tab, start = 0, t or 7, 1 @@ -64,7 +82,7 @@ local pattern = local spaces = tab-(current-1) % tab if spaces > 0 then extra = extra + spaces - 1 - return rep(" ",spaces) + return nspaces[spaces] -- rep(" ",spaces) else return "" end |