From d3fc2d1739188cbe00981e924de240212032f821 Mon Sep 17 00:00:00 2001
From: Jeremy Penner <jeremy@sporktania.com>
Date: Fri, 20 Nov 2020 12:51:59 -0500
Subject: [PATCH] Implement rainbow parens

---
 support/lite/plugins/rainbowparen.lua     | 58 +++++++++++++++++++++++
 vendor/lite/data/plugins/rainbowparen.lua |  1 +
 2 files changed, 59 insertions(+)
 create mode 100644 support/lite/plugins/rainbowparen.lua
 create mode 120000 vendor/lite/data/plugins/rainbowparen.lua

diff --git a/support/lite/plugins/rainbowparen.lua b/support/lite/plugins/rainbowparen.lua
new file mode 100644
index 0000000..b2689f0
--- /dev/null
+++ b/support/lite/plugins/rainbowparen.lua
@@ -0,0 +1,58 @@
+local tokenizer = require "core.tokenizer"
+local style = require "core.style"
+local common = require "core.common"
+
+local tokenize = tokenizer.tokenize
+local closers = {
+  ["("] = ")",
+  ["["] = "]",
+  ["{"] = "}"
+}
+local function parenstyle(parenstack)
+  return "paren" .. ((#parenstack % 5) + 1)
+end
+function tokenizer.tokenize(syntax, text, state)
+  state = state or {}
+  local res, istate = tokenize(syntax, text, state.istate)
+  local parenstack = state.parenstack or ""
+  local newres = {}
+  -- split parens out
+  -- the stock tokenizer can't do this because it merges identical adjacent tokens
+  for i, type, text in tokenizer.each_token(res) do
+    if type == "normal" or type == "symbol" then
+      for normtext1, paren, normtext2 in text:gmatch("([^%(%[{}%]%)]*)([%(%[{}%]%)]?)([^%(%[{}%]%)]*)") do
+        if #normtext1 > 0 then
+          table.insert(newres, type)
+          table.insert(newres, normtext1)
+        end
+        if #paren > 0 then
+          if paren == parenstack:sub(-1) then -- expected closer
+            parenstack = parenstack:sub(1, -2)
+            table.insert(newres, parenstyle(parenstack))
+          elseif closers[paren] then -- opener
+            table.insert(newres, parenstyle(parenstack))
+            parenstack = parenstack .. closers[paren]
+          else -- unexpected closer
+            table.insert(newres, "paren_unbalanced")
+          end
+          table.insert(newres, paren)
+        end
+        if #normtext2 > 0 then
+          table.insert(newres, type)
+          table.insert(newres, normtext2)
+        end
+      end
+    else
+      table.insert(newres, type)
+      table.insert(newres, text)
+    end
+  end
+  return newres, { parenstack = parenstack, istate = istate }
+end
+
+style.syntax.paren_unbalanced = style.syntax.paren_unbalanced or { common.color "#DC0408" }
+style.syntax.paren1  =  style.syntax.paren1 or { common.color "#FC6F71"}
+style.syntax.paren2  =  style.syntax.paren2 or { common.color "#fcb053"}
+style.syntax.paren3  =  style.syntax.paren3 or { common.color "#fcd476"}
+style.syntax.paren4  =  style.syntax.paren4 or { common.color "#52dab2"}
+style.syntax.paren5  =  style.syntax.paren5 or { common.color "#5a98cf"}
diff --git a/vendor/lite/data/plugins/rainbowparen.lua b/vendor/lite/data/plugins/rainbowparen.lua
new file mode 120000
index 0000000..a198667
--- /dev/null
+++ b/vendor/lite/data/plugins/rainbowparen.lua
@@ -0,0 +1 @@
+../../../../support/lite/plugins/rainbowparen.lua
\ No newline at end of file