Add language plugin for ERB files (#130)

* Add language plugin for ERB files

erb files typically has filename.html.erb extension they contain
html markup and embedded ruby code this file should properly
syntax highlight both html and ruby parts

* merge html/htm in filetype check

1 files changed, 55 insertions, 0 deletions

diff --git a/plugins/language_erb.lua b/plugins/language_erb.lua
new file mode 100644
index 0000000..d55b48c
--- /dev/null
+++ b/plugins/language_erb.lua
@@ -0,0 +1,55 @@
+-- mod-version:3
+local syntax = require "core.syntax"
+
+syntax.add {
+  name = "html-eruby",
+  files = { "%.html?%.erb$", "%.erb$" },
+  block_comment = { "<!--", "-->" },
+  patterns = {
+    {
+      pattern = {
+        "<%s*[sS][cC][rR][iI][pP][tT]%f[%s>].->",
+        "<%s*/%s*[sS][cC][rR][iI][pP][tT]%s*>"
+      },
+      syntax = ".js",
+      type = "function"
+    },
+    {
+      pattern = {
+        "<%s*[sS][tT][yY][lL][eE]%f[%s>].->",
+        "<%s*/%s*[sS][tT][yY][lL][eE]%s*>"
+      },
+      syntax = ".css",
+      type = "function"
+    },
+    {
+      pattern = {
+        "<%%",
+        "%%>"
+      },
+      syntax = ".rb",
+      type = "function"
+    },
+    {
+      pattern = {
+        "<%%=",
+        "%%>"
+      },
+      syntax = ".rb",
+      type = "function"
+    },
+    { pattern = { "<!%-%-", "%-%->" },     type = "comment"  },
+    { pattern = { '%f[^>][^<]', '%f[<]' }, type = "normal"   },
+    { pattern = { '"', '"', '\\' },        type = "string"   },
+    { pattern = { "'", "'", '\\' },        type = "string"   },
+    { pattern = "0x[%da-fA-F]+",           type = "number"   },
+    { pattern = "-?%d+[%d%.]*f?",          type = "number"   },
+    { pattern = "-?%.?%d+f?",              type = "number"   },
+    { pattern = "%f[^<]![%a_][%w_]*",      type = "keyword2" },
+    { pattern = "%f[^<][%a_][%w_]*",       type = "function" },
+    { pattern = "%f[^<]/[%a_][%w_]*",      type = "function" },
+    { pattern = "[%a_][%w_]*",             type = "keyword"  },
+    { pattern = "[/<>=]",                  type = "operator" },
+  },
+  symbols = {},
+}