feat(grit): implement Grit built-ins (#3987)

crates/biome_grit_patterns/Cargo.toml

@@ -25,6 +25,7 @@ grit-pattern-matcher = { version = "0.3" }
 grit-util            = { version = "0.3" }
 im                   = { version = "15.1.0" }
 path-absolutize      = { version = "3.1.1", optional = false, features = ["use_unix_paths_on_wasm"] }
+rand                 = { version = "0.8" }
 regex                = { workspace = true }
 rustc-hash           = { workspace = true }
 serde                = { workspace = true, features = ["derive"] }

crates/biome_grit_patterns/src/errors.rs

@@ -15,6 +15,9 @@ pub enum CompileError {
     /// Used for missing syntax nodes.
     MissingSyntaxNode,
 
+    /// A built-in function call was discovered in an unexpected context.
+    UnexpectedBuiltinCall(String),
+
     /// A metavariables was discovered in an unexpected context.
     UnexpectedMetavariable,
 
@@ -95,6 +98,9 @@ impl Diagnostic for CompileError {
             CompileError::MissingSyntaxNode => {
                 fmt.write_markup(markup! { "A syntax node was missing" })
             }
+            CompileError::UnexpectedBuiltinCall(name) => {
+                fmt.write_markup(markup! { "Unexpected call to built-in: "{{name}}"()" })
+            }
             CompileError::UnexpectedMetavariable => {
                 fmt.write_markup(markup! { "Unexpected metavariable" })
             }
@@ -176,6 +182,11 @@ impl Diagnostic for CompileError {
 
     fn advices(&self, visitor: &mut dyn biome_diagnostics::Visit) -> std::io::Result<()> {
         match self {
+            CompileError::UnexpectedBuiltinCall(name) => visitor.record_log(
+                LogCategory::Info,
+                &markup! { "Built-in "{{name}}" can only be used on the right-hand side of a rewrite" }
+                    .to_owned(),
+            ),
             CompileError::ReservedMetavariable(_) => visitor.record_log(
                 LogCategory::Info,
                 &markup! { "Try using a different variable name" }.to_owned(),