Add OpenSCAD syntax highlighting support. (#413)

* WIP: added early/partial OpenSCAD syntax highlighing.

* Added manifest entry and some keywords.

* WIP: added new patterns and tidied up keywords.

* Updated last patterns.

* Added entry to meta-languages package.

* Bumped meta_languages version.

* Update plugins/language_openscad.lua

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>

* Update plugins/language_openscad.lua

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>

* Update manifest.json

---------

Co-authored-by: Guldoman <giulio.lettieri@gmail.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/plugins/language_openscad.lua b/plugins/language_openscad.lua
new file mode 100644
index 0000000..078ec03
--- /dev/null
+++ b/plugins/language_openscad.lua
@@ -0,0 +1,116 @@
+-- mod-version:3
+local syntax = require "core.syntax"
+
+syntax.add {
+  name = "OpenSCAD",
+  files = {"%.scad$"},
+  comment = "//",
+  block_comment = { "/*", "*/" },
+  patterns = {
+    { pattern = "//.*",                          type = "comment"  }, -- Single-line comment
+    { pattern = { "/%*", "%*/" },                type = "comment"  }, -- Multi-line comment
+    { pattern = { '"', '"', '\\' },              type = "string"   }, -- String, double quotes
+    { pattern = { "'", "'", '\\' },              type = "string"   }, -- String, apices
+    { pattern = "-?0x%x+",                       type = "number"   }, -- ?
+    { pattern = "-?%d+[%d%.eE]*[a-zA-Z]?",       type = "number"   }, -- ?
+    { pattern = "-?%.?%d+",                      type = "number"   }, -- ?
+    { pattern = "[%+%-=/%*%^%%<>!~|&%?%:]",      type = "operator" }, -- Operators
+    { pattern = "[%a_][%w_]*%f[(]",              type = "function" }, -- Functions
+    { regex   = "\\$[a-zA-Z]+",                  type = "keyword"  }, -- Special variables
+    { pattern = "[%a_][%w_]*",                   type = "symbol"   },
+  },
+  symbols = {
+    -- ?
+    ["var"]               = "keyword",
+    ["module"]            = "keyword",
+    ["function"]          = "keyword",
+    ["include"]           = "keyword",
+    ["use"]               = "keyword",
+    -- Constants
+    ["undef"]             = "keyword2",
+    ["PI"]                = "keyword2",
+    -- 2D
+    ["circle"]            = "keyword",
+    ["square"]            = "keyword",
+    ["polygon"]           = "keyword",
+    ["text"]              = "keyword",
+    ["import"]            = "keyword",
+    ["projection"]        = "keyword",
+    -- 3D
+    ["sphere"]            = "keyword",
+    ["cube"]              = "keyword",
+    ["cylinder"]          = "keyword",
+    ["polyhedron"]        = "keyword",
+    ["surface"]           = "keyword",
+    -- Transformations
+    ["linear_extrude"]    = "keyword",
+    ["rotate_extrude"]    = "keyword",
+    ["translate"]         = "keyword",
+    ["rotate"]            = "keyword",
+    ["scale"]             = "keyword",
+    ["resize"]            = "keyword",
+    ["mirror"]            = "keyword",
+    ["multmatrix"]        = "keyword",
+    ["color"]             = "keyword",
+    ["offset"]            = "keyword",
+    ["hull"]              = "keyword",
+    ["minkowski"]         = "keyword",
+    -- Boolean Operations
+    ["union"]             = "keyword",
+    ["difference"]        = "keyword",
+    ["intersection"]      = "keyword",
+    -- Flow Control
+    ["for"]               = "keyword",
+    ["each"]              = "keyword",
+    -- Type Test Functions
+    ["is_undef"]          = "function",
+    ["is_bool"]           = "function",
+    ["is_num"]            = "function",
+    ["is_string"]         = "function",
+    ["is_list"]           = "function",
+    ["is_function"]       = "function",
+    -- Other
+    ["echo"]              = "keyword",
+    ["render"]            = "keyword",
+    ["children"]          = "keyword",
+    ["assert"]            = "keyword",
+    -- Functions
+    ["concat"]            = "function",
+    ["lookup"]            = "function",
+    ["str"]               = "function",
+    ["chr"]               = "function",
+    ["ord"]               = "function",
+    ["search"]            = "function",
+    ["version"]           = "function",
+    ["version_num"]       = "function",
+    ["parent_module"]     = "function",    
+    -- Math Functions
+    ["abs"]               = "keyword",
+    ["sign"]              = "keyword",
+    ["sin"]               = "keyword",
+    ["cos"]               = "keyword",
+    ["tan"]               = "keyword",
+    ["acos"]              = "keyword",
+    ["asin"]              = "keyword",
+    ["atan"]              = "keyword",
+    ["atan2"]             = "keyword",
+    ["floor"]             = "keyword",
+    ["round"]             = "keyword",
+    ["ceil"]              = "keyword",
+    ["ln"]                = "keyword",
+    ["len"]               = "keyword",
+    ["let"]               = "keyword",
+    ["log"]               = "keyword",
+    ["pow"]               = "keyword",
+    ["sqrt"]              = "keyword",
+    ["exp"]               = "keyword",
+    ["rands"]             = "keyword",
+    ["min"]               = "keyword",
+    ["max"]               = "keyword",
+    ["norm"]              = "keyword",
+    ["cross"]             = "keyword",
+    -- Literals
+    ["true"]              = "literal",
+    ["false"]             = "literal",
+  }
+}