Add Lua syntax highlighting support

assets/highlighting-tests/lua.lua

@@ -0,0 +1,100 @@
+-- Comments
+-- Single-line comment
+
+--[[
+Multi-line comment
+]]
+
+--[=[
+Extended multi-line comment
+]=]
+
+-- Numbers
+local n1 = 42
+local n2 = 3.14
+local n3 = 0.5
+local n4 = 1e10
+local n5 = 1.5e-3
+local n6 = 0xff
+local n7 = 0xFF
+local n8 = 0x1f
+
+-- Constants
+local c1 = true
+local c2 = false
+local c3 = nil
+
+-- Strings
+local s1 = 'single quotes with escape: \' \n \t \\'
+local s2 = "double quotes with escape: \" \n \t \\"
+
+local s3 = [[
+Multi-line string
+]]
+
+local s4 = [=[
+Extended multi-line string
+]=]
+
+-- Control flow keywords
+if true then
+elseif false then
+else
+end
+
+for i = 1, 10 do
+    if i == 5 then
+        break
+    end
+end
+
+while false do
+end
+
+repeat
+until true
+
+-- Other keywords
+local x = 1
+local _y = not false and true or nil
+local value = "sample"
+local items = { 1, 2, 3 }
+local object = {
+    method = function(self)
+        return self
+    end,
+}
+
+function greet(name)
+    return "Hello, " .. name
+end
+
+local function helper()
+    return x + n1
+end
+
+type Point = {
+    x: number,
+    y: number,
+}
+
+export type Callback = (value: string) -> ()
+
+local kind = typeof(value)
+
+for _, item in pairs(items) do
+    print(item)
+    continue
+end
+
+-- Function calls
+print("hello")
+greet("world")
+table.insert(items, 42)
+object:method()
+
+print(n1, n2, n3, n4, n5, n6, n7, n8)
+print(c1, c2, c3)
+print(s1, s2, s3, s4)
+print(kind)
+print(helper())

assets/highlighting-tests/markdown.md

@@ -80,6 +80,16 @@ export function greet(name) {
 }
 ```
 
+```lua
+local function greet(name)
+    return "hello " .. name
+end
+```
+
+```luau
+export type Greeting = (name: string) -> string
+```
+
 ```python
 def greet(name: str) -> str:
     return f"hello {name}"

crates/lsh/definitions/lua.lsh

@@ -0,0 +1,80 @@
+#[display_name = "Lua"]
+#[path = "**/*.lua"]
+#[path = "**/*.luau"]
+pub fn lua() {
+    until /$/ {
+        yield other;
+
+        if /--\[\[/ {
+            loop {
+                yield comment;
+                if /\]\]/ {
+                    yield comment;
+                    break;
+                }
+                await input;
+            }
+        } else if /--\[=\[/ {
+            loop {
+                yield comment;
+                if /\]=\]/ {
+                    yield comment;
+                    break;
+                }
+                await input;
+            }
+        } else if /--.*/ {
+            yield comment;
+        } else if /\[\[/ {
+            loop {
+                yield string;
+                if /\]\]/ {
+                    yield string;
+                    break;
+                }
+                await input;
+            }
+        } else if /\[=\[/ {
+            loop {
+                yield string;
+                if /\]=\]/ {
+                    yield string;
+                    break;
+                }
+                await input;
+            }
+        } else if /'/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /'/ { yield string; break; }
+                await input;
+            }
+        } else if /"/ {
+            until /$/ {
+                yield string;
+                if /\\./ {}
+                else if /"/ { yield string; break; }
+                await input;
+            }
+        } else if /(?:break|continue|do|else|elseif|end|for|function|goto|if|in|repeat|return|then|until|while)\>/ {
+            yield keyword.control;
+        } else if /(?:and|export|local|not|or|type|typeof)\>/ {
+            yield keyword.other;
+        } else if /(?:true|false|nil)\>/ {
+            yield constant.language;
+        } else if /(?i:(?:0x[\da-f]+(?:\.[\da-f]+)?(?:p[+-]?\d+)?|-?(?:\d+(?:\.\d*)?|\.\d+)(?:e[+-]?\d+)?))/ {
+            if /\w+/ {
+                // Invalid numeric literal
+            } else {
+                yield constant.numeric;
+            }
+        } else if /(\w+)\s*\(/ {
+            yield $1 as method;
+        } else if /\w+/ {
+            // Gobble word chars to align the next iteration on a word boundary.
+        }
+
+        yield other;
+    }
+}

crates/lsh/definitions/markdown.lsh

@@ -60,6 +60,16 @@ pub fn markdown() {
                     if /.*/ {}
                 }
             }
+        } else if /(?i:lua|luau)/ {
+            loop {
+                await input;
+                if /\s*```/ {
+                    return;
+                } else {
+                    lua();
+                    if /.*/ {}
+                }
+            }
         } else if /(?i:py)/ {
             loop {
                 await input;