recparse.lua (35a7f9b) - memoire

recparse.lua

--[[
    a Recfile is (to simplify) a sequence of records
    a record is a sequence of fields
    a field is a label-value pair
    a label is an identifier
    a value is a string
]]

--[[
    maps text from a Recfile into a sequence of records
    returns (on success) a table of tables of tables of two strings (label and value)
    returns (on failure) nil
]]
local function text2recs(str)
    local ret = {}
    local cr = {}
    local cl = nil
    local cv = nil
    -- Rec is line-based
    for line in str:gmatch "([^\n]*)\n" do
        -- continuation lines
        if cv and cv:sub(-1) == "\\" then
            cv = cv:sub(1, -2) .. line
        elseif line:sub(1, 1) == "+" then
            cv = cv .. "\n" .. line:gsub("^%+ ?", "")
        -- blank lines separate records
        elseif line:match "^%s*$" then
            -- add field to record if non-empty
            if cl then
                table.insert(cr, { k = cl, v = cv })
            end
            cl = nil
            cv = nil
            -- add record to return value if non-empty
            if next(cr) then
                table.insert(ret, cr)
            end
            cr = {}
        -- lines starting with # are comments
        elseif line:sub(1, 1) == "#" then
            if cl then
                table.insert(cr, { k = cl, v = cv })
            end
            cl = nil
            cv = nil
        -- new field
        else
            if cl then
                table.insert(cr, { k = cl, v = cv })
            end
            cl, cv = line:match "^([%a%%][%w_]*):%s(.*)"
            -- no match? bad field
            if not cl then
                return nil
            end
        end
    end
    if cl then
        table.insert(cr, { k = cl, v = cv })
    end
    if next(cr) then
        table.insert(ret, cr)
    end
    return ret
end

return text2recs

memoire

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