From aafadc0d657faa99e483a4f2c70dbe64491b1802 Mon Sep 17 00:00:00 2001
From: Amaan Qureshi <amaanq12@gmail.com>
Date: Sun, 18 Jun 2023 10:44:07 -0400
Subject: [PATCH] refactor: use C for the external scanner (#16)

---
 binding.gyp                   |  2 +-
 bindings/rust/build.rs        | 19 -------------------
 src/{scanner.cc => scanner.c} | 27 ++++++++++++++++-----------
 3 files changed, 17 insertions(+), 31 deletions(-)
 rename src/{scanner.cc => scanner.c} (84%)

diff --git a/binding.gyp b/binding.gyp
index a2beb8a..634f20f 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -9,7 +9,7 @@
       "sources": [
         "bindings/node/binding.cc",
         "src/parser.c",
-        # If your language uses an external scanner, add it here.
+		"scanner.c",
       ],
       "cflags_c": [
         "-std=c99",
diff --git a/bindings/rust/build.rs b/bindings/rust/build.rs
index 618e90a..8f87ee6 100644
--- a/bindings/rust/build.rs
+++ b/bindings/rust/build.rs
@@ -10,29 +10,10 @@ fn main() {
     let parser_path = src_dir.join("parser.c");
     c_config.file(&parser_path);
 
-    // If your language uses an external scanner written in C,
-    // then include this block of code:
-
-    /*
     let scanner_path = src_dir.join("scanner.c");
     c_config.file(&scanner_path);
     println!("cargo:rerun-if-changed={}", scanner_path.to_str().unwrap());
-    */
 
     c_config.compile("parser");
     println!("cargo:rerun-if-changed={}", parser_path.to_str().unwrap());
-
-    // If your language uses an external scanner written in C++,
-    // then include this block of code:
-
-    let mut cpp_config = cc::Build::new();
-    cpp_config.cpp(true);
-    cpp_config.include(&src_dir);
-    cpp_config
-        .flag_if_supported("-Wno-unused-parameter")
-        .flag_if_supported("-Wno-unused-but-set-variable");
-    let scanner_path = src_dir.join("scanner.cc");
-    cpp_config.file(&scanner_path);
-    cpp_config.compile("scanner");
-    println!("cargo:rerun-if-changed={}", scanner_path.to_str().unwrap());
 }
diff --git a/src/scanner.cc b/src/scanner.c
similarity index 84%
rename from src/scanner.cc
rename to src/scanner.c
index 886bb33..d03a911 100644
--- a/src/scanner.cc
+++ b/src/scanner.c
@@ -1,16 +1,19 @@
-#include <cwctype>
 #include <tree_sitter/parser.h>
+#include <wctype.h>
 
-namespace {
 enum TokenType { BRACKET_ARGUMENT, BRACKET_COMMENT, LINE_COMMENT };
-void skip(TSLexer *lexer) { lexer->advance(lexer, true); }
-void advance(TSLexer *lexer) { lexer->advance(lexer, false); }
-void skip_wspace(TSLexer *lexer) {
-  while (std::iswspace(lexer->lookahead)) {
+
+static void skip(TSLexer *lexer) { lexer->advance(lexer, true); }
+
+static void advance(TSLexer *lexer) { lexer->advance(lexer, false); }
+
+static void skip_wspace(TSLexer *lexer) {
+  while (iswspace(lexer->lookahead)) {
     skip(lexer);
   }
 }
-bool is_bracket_argument(TSLexer *lexer) {
+
+static bool is_bracket_argument(TSLexer *lexer) {
   if (lexer->lookahead != '[') {
     return false;
   }
@@ -45,7 +48,8 @@ bool is_bracket_argument(TSLexer *lexer) {
   }
   return false;
 }
-bool scan(void *payload, TSLexer *lexer, bool const *valid_symbols) {
+
+static bool scan(void *payload, TSLexer *lexer, bool const *valid_symbols) {
   skip_wspace(lexer);
 
   if (lexer->lookahead != '#' && valid_symbols[BRACKET_ARGUMENT]) {
@@ -72,19 +76,20 @@ bool scan(void *payload, TSLexer *lexer, bool const *valid_symbols) {
   return false;
 }
 
-} // namespace
-extern "C" {
 void *tree_sitter_cmake_external_scanner_create() { return NULL; }
+
 void tree_sitter_cmake_external_scanner_destroy(void *payload) {}
+
 unsigned tree_sitter_cmake_external_scanner_serialize(void *payload,
                                                       char *buffer) {
   return 0;
 }
+
 void tree_sitter_cmake_external_scanner_deserialize(void *payload,
                                                     char const *buffer,
                                                     unsigned length) {}
+
 bool tree_sitter_cmake_external_scanner_scan(void *payload, TSLexer *lexer,
                                              bool const *valid_symbols) {
   return scan(payload, lexer, valid_symbols);
 }
-}