syntax: add Gleam language support

runtime/syntax/gleam.yaml

@@ -0,0 +1,50 @@
+detect:
+  filename: "\\.gleam$"
+
+rules:
+  # Keywords (from Gleam compiler token.rs)
+  - statement: "\\b(as|assert|auto|case|const|delegate|derive|echo|else|fn|if|implement|import|let|macro|opaque|panic|pub|test|todo|type|use)\\b"
+
+  # Built-in types (removed Nil - it is a constant)
+  - type: "\\b(Int|Float|String|Bool|List|Option|Result|BitArray)\\b"
+
+  # Constants
+  - constant: "\\b(True|False|Nil)\\b"
+
+  # Type constructors / Custom types (must come after built-in types)
+  - type: "\\b[A-Z][a-zA-Z0-9_]*\\b"
+
+  # Attributes (@external, @deprecated, @target, etc.)
+  - preproc: "@[a-z][a-z_]*"
+
+  # Operators (using statement for consistent coloring)
+  - statement: "(\\|>|->|<-)" # Pipe and arrow
+  - statement: "(\\.\\.|<>)" # Range and concat
+  - statement: "(==|!=|<=\\.|>=\\.|<\\.|>\\.|<=|>=)" # Comparison
+  - statement: "(&&|\\|\\|)" # Logical
+  - statement: "(\\+\\.|-\\.|\\*\\.|/\\.|\\+|-|\\*|/|%)" # Arithmetic
+  - statement: "(=|<|>|!|<<|>>)" # Other
+
+  # Numbers (from Python syntax with underscore support)
+  - constant.number: "\\b0b[01](_?[01])*\\b"
+  - constant.number: "\\b0o[0-7](_?[0-7])*\\b"
+  - constant.number: "\\b0x[0-9a-fA-F](_?[0-9a-fA-F])*\\b"
+  - constant.number: "\\b[0-9](_?[0-9])*(\\.[0-9](_?[0-9])*)?([eE][+-]?[0-9](_?[0-9])*)?\\b"
+
+  # Tuple syntax
+  - special: "#\\("
+
+  # Strings
+  - constant.string:
+      start: '"'
+      end: '"'
+      skip: "\\\\."
+      rules:
+        - constant.specialChar: "\\\\."
+
+  # Comments
+  - comment:
+      start: "//"
+      end: "$"
+      rules:
+        - todo: "(TODO|FIXME|XXX):?"