From 4f406ae891113fc1bfda308052c835a185188670 Mon Sep 17 00:00:00 2001
From: tiyn <tiyn@posteo.eu>
Date: Fri, 20 Feb 2026 07:27:32 +0100
Subject: [PATCH] initial push

---
 README.md          |  6 +++++-
 lua/viper/init.lua | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 lua/viper/init.lua

diff --git a/README.md b/README.md
index 380db6c..8020488 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,6 @@
 # viper.nvim
-Simple highlighting tool for the verification language viper.
+
+viper.nvim is a simple plugin that adds basic highlighting capabilities to NeoVim for the
+verification language [Viper](https://github.com/viperproject).
+
+Currently it uses simple parsing and word matching for this and does not use any tree structures.
diff --git a/lua/viper/init.lua b/lua/viper/init.lua
new file mode 100644
index 0000000..8a001e2
--- /dev/null
+++ b/lua/viper/init.lua
@@ -0,0 +1,45 @@
+local M = {}
+
+function M.setup()
+  local group = vim.api.nvim_create_augroup("ViperSyntax", { clear = true })
+
+  local function enable_viper_syntax()
+    if vim.b.viper_syntax_loaded then
+      return
+    end
+    vim.b.viper_syntax_loaded = true
+
+    vim.cmd("syntax enable")
+    vim.cmd("syntax clear")
+
+    vim.cmd([[
+      syntax keyword viperKeyword method function returns requires ensures invariant
+      syntax keyword viperKeyword if else while var field predicate
+      syntax keyword viperKeyword assert assume inhale exhale fold unfold
+
+      syntax keyword viperType Int Bool Ref
+
+      syntax match viperComment "//.*$"
+      syntax match viperNumber "\v\d+"
+    ]])
+
+    vim.api.nvim_set_hl(0, "viperKeyword", { link = "Keyword" })
+    vim.api.nvim_set_hl(0, "viperType", { link = "Type" })
+    vim.api.nvim_set_hl(0, "viperComment", { link = "Comment" })
+    vim.api.nvim_set_hl(0, "viperNumber", { link = "Number" })
+  end
+
+  vim.api.nvim_create_autocmd("FileType", {
+    group = group,
+    pattern = "viper",
+    callback = enable_viper_syntax,
+  })
+
+  vim.api.nvim_create_autocmd({ "BufRead", "BufNewFile" }, {
+    group = group,
+    pattern = "*.vpr",
+    callback = enable_viper_syntax,
+  })
+end
+
+return M