handles sections, paragraphs, transitions, targets

1 files changed, 200 insertions, 0 deletions

diff --git a/rst_context.lua b/rst_context.lua
new file mode 100644
index 0000000..6363dfe
--- /dev/null
+++ b/rst_context.lua
@@ -0,0 +1,200 @@
+#!/usr/bin/env texlua
+--------------------------------------------------------------------------------
+--         FILE:  rst_context.lua
+--        USAGE:  ./rst_context.lua 
+--  DESCRIPTION:  
+--      OPTIONS:  ---
+-- REQUIREMENTS:  ---
+--       AUTHOR:  Philipp Gesang (Phg), <megas.kapaneus@gmail.com>
+--      VERSION:  1.0
+--      CREATED:  31/08/10 19:35:15 CEST
+--------------------------------------------------------------------------------
+--
+
+
+require "lpeg"
+local C, Cb, Cc, Cg, Cmt, Cp, Cs, Ct, P, R, S, V, match = lpeg.C, lpeg.Cb, lpeg.Cc, lpeg.Cg, lpeg.Cmt, lpeg.Cp, lpeg.Cs, lpeg.Ct, lpeg.P, lpeg.R, lpeg.S, lpeg.V, lpeg.match
+
+if not context then -- standard context lpeg stripper from l-string.lua
+    local stripper = P{
+        [1] = "stripper",
+        stripper = V"space"^0 * C((V"space"^0 * V"nospace"^1)^0),
+        space    = S(" \t\v\n"),
+        nospace  = 1 - V"space",
+    }
+    function string.strip(str)
+        return stripper:match(str) or ""
+    end 
+end
+
+
+local rst_context = {}
+rst_context.collected_references = {}
+rst_context.collected_adornments = {}
+rst_context.last_section_level   = 0
+rst_context.anonymous_links      = 0
+rst_context.context_references   = {}
+
+-- So we can use crefs[n][2] to refer to the place where the reference was
+-- created.
+local function get_context_reference (str)
+    local crefs = rst_context.context_references
+    refstring = "__contextref__" .. tostring(#crefs + 1)
+    crefs[#crefs + 1] = { refstring, str }
+    return refstring
+end
+
+function rst_context.emphasis (str)
+    return [[{\\em ]] .. str .. [[}]]
+end
+
+function rst_context.strong_emphasis (str)
+    return [[{\\sc ]] .. str .. [[}]]
+end
+
+function rst_context.paragraph (str)
+    return "\n" .. [[\\startparagraph]] .. "\n" .. str .. "\n".. [[\\stopparagraph]] .. "\n"
+end
+
+function rst_context.literal (str)
+    str = str:gsub([[\]], [[\\]]) -- evade escaping of backslashes
+    return [[\\type{]] .. str .. [[}]]
+end
+
+
+function rst_context.interpreted_text (...)
+    local tab = { ... }
+    --print (tab, #tab, tab[1], tab[2], tab[3])
+    local role, str
+    role = tab[1]:match("^:(.*):$") or tab[3]:match("^:(.*):$")
+    str  = tab[2]
+
+    if not role then -- implicit role
+        role = "emphasis"
+    end
+
+    --print(role, str)
+
+    return rst_context[role](str)
+end
+
+function rst_context.link_standalone (str)
+    return "\n"
+        .. [[\\goto{\\hyphenatedurl{]]
+        .. str
+        .. [[}}[url(]]
+        .. str
+        .. [=[)]]=]
+end
+
+function rst_context.reference (str)
+    str = str:match("[^_]*")
+    local link = rst_context.collected_references[str]
+    if not link then -- TODO make warning instead
+        return([[{\\sc UNDEFINED REFERENCE ]] .. str .. [[}.]])
+    end
+    return [[\\goto{]]
+        .. str
+        .. [[}[url(]]
+        .. link
+        .. [=[)]]=]
+end
+
+function rst_context.target (tab)
+    --print("GOT ONE!")
+    --local tab = { ... }
+    local refs = rst_context.collected_references
+    local target = tab[#tab] -- Ct + C could be clearer but who cares
+    tab[#tab] = nil
+
+    local function resolve_indirect (r)
+        if r and r:match(".*_$") then -- pointing elsewhere
+            return resolve_indirect (refs[r:match("(.*)_$")]) or "need another run!" -- TODO multiple runs && data collection
+        end
+        return r
+    end
+
+    local function create_anonymous ()
+        rst_context.anonymous_links = rst_context.anonymous_links + 1
+        return "__anon__" .. rst_context.anonymous_links
+    end
+
+
+    target = resolve_indirect (target)
+
+    for i=1,#tab do
+        local id = tab[i]:gsub("\\:",":") -- deescaping
+        id = id ~= "" and id or create_anonymous ()
+        refs[id] = refs[id] or target
+    end
+    return ""
+end
+
+function rst_context.escape (str)
+    return str:gsub("\\(.)", "%1")
+end
+
+function rst_context.joinindented (tab)
+    return table.concat (tab, "")
+end
+
+local sectionlevels = {
+    [1] = "chapter",
+    [2] = "section",
+    [3] = "subsection",
+    [4] = "subsubsection",
+    [5] = "subsubsubsection",
+}
+
+local function get_line_pattern (chr)
+    return P(chr)^1 * (-P(1))
+end
+
+function rst_context.section (...)  -- TODO general cleanup; move validity
+    local tab = { ... }             -- checking to parser.
+    local section, str = true, ""
+    local adornchar 
+    if #tab == 3 then -- TODO use unicode length with ConTeXt
+        --print(">>"..tab[1].."<>"..tab[2].."<<")
+        adornchar = tab[1]:sub(1,1)
+        --  overline == underline && len(overline) = len(sectionstring)
+        section = tab[1] == tab[3] and #tab[1] >= #tab[2] 
+        -- if overline consists only of one char then keep truth value else
+        -- false
+        section = get_line_pattern(adornchar):match(tab[1]) ~= nil and section
+        str = string.strip(tab[2])
+    else -- no overline
+        --print(">>"..tab[1].."<>"..tab[2].."<<")
+        adornchar = tab[2]:sub(1,1)
+        section = #tab[1] <= #tab[2]
+        section = get_line_pattern(adornchar):match(tab[2]) ~= nil and section
+        str = tab[1]
+    end
+
+    if section then -- determine level
+        local level = rst_context.last_section_level
+        local rca = rst_context.collected_adornments
+        if rca[adornchar] then
+            level = rca[adornchar]
+        else
+            level = level + 1
+            rca[adornchar] = level
+            rst_context.last_section_level = level
+        end
+
+        ref = get_context_reference (str)
+
+        str = string.format("\n\\\\%s[%s]{%s}\n", sectionlevels[level], ref, str)
+    end
+
+    return section and str or ""
+end
+
+-- Prime time for the fancybreak module.
+function rst_context.transition (str)
+    return "\n\\hrule\n"
+end
+
+
+
+return rst_context