From 0a64fe1028c5a9268218b5f3fafa76818b08edf3 Mon Sep 17 00:00:00 2001
From: Hanson Char <hanson.char@gmail.com>
Date: Tue, 18 Jun 2024 12:25:02 -0700
Subject: [PATCH] wip - examplesfinder.lua

---
 doc/generic/pgf/lib/examplesfinder.lua | 102 +++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 doc/generic/pgf/lib/examplesfinder.lua

diff --git a/doc/generic/pgf/lib/examplesfinder.lua b/doc/generic/pgf/lib/examplesfinder.lua
new file mode 100644
index 000000000..2422450b2
--- /dev/null
+++ b/doc/generic/pgf/lib/examplesfinder.lua
@@ -0,0 +1,102 @@
+local UNIT_TESTING = true
+
+if UNIT_TESTING then
+  local function pwd()
+    local info = debug.getinfo(1, "S")
+    local path = info.source:match("@(.*)")
+    local dir = path:match("(.*[/\\])") or "./"
+    return dir
+  end
+  package.path = pwd() .. "?.lua;" .. package.path
+  local luarocks_path = os.getenv("HOME") .. "/.luarocks/share/lua/5.3/?.lua"
+  package.path = package.path .. ";" .. luarocks_path
+end
+
+local lpeg = require("lpeg")
+local u = require("utils")
+local SP = u.SP
+local str = require("stringmatcher")
+local C, P, V, Ct, Cf, Cg = lpeg.C, lpeg.P, lpeg.V, lpeg.Ct, lpeg.Cf, lpeg.Cg
+local I =
+  lpeg.P(
+  function(_, i)
+    print("I:", i)
+    return true
+  end
+)
+
+local finder = {}
+
+local function reorg(t, k, v)
+  if type(k) == "string" then
+    u.set(t, k, v)
+  end
+  return t
+end
+
+-- Grammar to extract code from function call to "example" with a table parameter
+finder.grammar =
+  P {
+  "examples",
+  examples = SP * "examples" * SP * "=" * SP * "{" * SP * V "content" * SP * "}",
+  -- content = Cf(Ct"" * Cg(V("options") ^ -1 * Ct(V("exentry") ^ 1)), reorg),
+  content = Ct(V("options") ^ -1 * V("exentry") ^ 1),
+  options = V "optionskv" * P(",") ^ -1,
+  optionskv = Cg(C("options") * SP * "=" * SP * str),
+  exentry = SP * "{" * SP * V "excontent" * SP * "}" * P(",") ^ -1,
+  excontent = Cf(Ct "" * V("options") ^ -1 * V "code", u.set),
+  code = SP * V "codekv",
+  codekv = Cg(C("code") * SP * "=" * SP * str)
+}
+
+-- Unit tests and debugging
+
+local tostring = require "ml".tstring
+-- local test_case = [=[
+--   examples = {
+--     options = [[ top level options ]],
+--     {
+--       options = [[ first entry options ]],
+--       code = [[ first entry code ]]
+--     },
+--   }
+-- ]=]
+local test_case =
+  [=[
+  examples = {
+    options = [[ top level options ]],
+    {
+      options = [[ first entry options ]],
+      code = [[ first entry code ]]
+    },
+    {
+      code = [[ second entry code]]
+    }
+  }
+]=]
+
+local matches = finder.grammar:match(test_case)
+print(tostring(matches))
+-- local p = SP * P"examples" * SP * P"=" * SP *
+--     P"{" * SP * (P"options" * SP * P"=" * SP * str) ^ -1 * SP * P(",")^-1 * SP * I * P"}"
+-- local matches = p:match(test_case)
+-- print(tostring(matches))
+
+-- assert(#matches == 1)
+-- local e = matches[1]
+-- assert(tostring(finder.get_options(e)) == [[{preamble="\\usetikzlibrary{graphs,graphdrawing} \\usegdlibrary{layered"}]])
+-- assert(
+--     u.strip(finder.get_content(e)) ==
+--         u.strip(
+--             [[
+--    \begin{tikzpicture}
+--       \draw [help lines] (0,0) grid (2,2);
+
+--       \graph [layered layout, edges=rounded corners]
+--         { a -- {b, c [anchor here] } -- d -- a};
+--     \end{tikzpicture
+-- ]]
+--         )
+-- )
+
+return finder