memoire

Expands on Recfile read/write library
Parent 35a7f9b
John Smith

John Smith commited on 2021-309 23:32:01
Showing 1 changed files, with 43 additions and 9 deletions. 

`recparse.lua` has been moved to `recrw.lua` to better reflect its function:
it implements conversion from an internal representation to Rec,
not just the other way around.

The internal representation has changed from lists of label-value pairs
to lists pairing labels with lists of values,
to accommodate the duplication allowed in Rec.
recparse.lua
View file @ 50049a1
... ... 
@@ -8,7 +8,7 @@
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 --[[
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     maps text from a Recfile into a sequence of records
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-    returns (on success) a table of tables of tables of two strings (label and value)
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+    returns (on success) a table of tables of label-value-list pairs
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     returns (on failure) nil
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 ]]
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 local function text2recs(str)
... ... 
@@ -27,7 +27,11 @@ local function text2recs(str)
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         elseif line:match "^%s*$" then
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             -- add field to record if non-empty
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             if cl then
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-                table.insert(cr, { k = cl, v = cv })
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+                if cr[cl] then
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+                    table.insert(cr[cl], cv)
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+                else
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+                    cr[cl] = { cv }
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+                end
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             end
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             cl = nil
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             cv = nil
... ... 
@@ -39,24 +43,34 @@ local function text2recs(str)
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         -- lines starting with # are comments
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         elseif line:sub(1, 1) == "#" then
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             if cl then
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-                table.insert(cr, { k = cl, v = cv })
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+                if cr[cl] then
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+                    table.insert(cr[cl], cv)
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+                else
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+                    cr[cl] = { cv }
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+                end
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             end
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             cl = nil
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             cv = nil
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         -- new field
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         else
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             if cl then
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-                table.insert(cr, { k = cl, v = cv })
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+                if cr[cl] then
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+                    table.insert(cr[cl], cv)
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+                else
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+                    cr[cl] = { cv }
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+                end
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             end
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             cl, cv = line:match "^([%a%%][%w_]*):%s(.*)"
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             -- no match? bad field
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-            if not cl then
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-                return nil
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-            end
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+            if not cl then return nil end
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         end
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     end
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     if cl then
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-        table.insert(cr, { k = cl, v = cv })
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+        if cr[cl] then
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+            table.insert(cr[cl], cv)
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+        else
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+            cr[cl] = { cv }
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+        end
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     end
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     if next(cr) then
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         table.insert(ret, cr)
... ... 
@@ -64,4 +78,24 @@ local function text2recs(str)
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     return ret
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 end
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-return text2recs
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+--[[
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+    maps a sequence of records into text for a Recfile
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+    returns (on success) a string
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+    returns (on failure) nil
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+]]
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+local function recs2text(recs)
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+    local ret = ""
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+    -- go through records
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+    for i, rec in ipairs(recs) do
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+        for label, vl in pairs(rec) do
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+            for j, value in ipairs(vl) do
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+                ret = ret .. string.format("\n%s: %s", label, value:gsub("\n", "\n+ "))
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+            end
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+        end
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+        ret = ret .. "\n"
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+    end
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+    return ret
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+end
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+
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+
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+return { read = text2recs, write = recs2text }
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