Two ways to add c lang highlight into TextArea.code_editor

[python-and-novella]

Use tree_sitter_language_pack or tree_sitter_c

try:
    from tree_sitter import Language
    from tree_sitter_c import language as c_lang
    tree_sitter = True
except ImportError:
    try:
        from tree_sitter_language_pack import get_language
    except ImportError:
        raise Exception('No method to parse language.')
    tree_sitter = False

# 特定语言的库需要与tree_sitter匹配
# tree_sitter==0.24.*时，兼容的LANGUAGE_VERSION为13、14
# tree_sitter_c==0.23.4的LANGUAGE_VERSION为14
# tree_sitter_c==0.23.5的LANGUAGE_VERSION为15
# 因此需要安装tree_sitter_c==0.23.4
# 命令行为 pip install tree-sitter-c==0.23.4

from textual.app import App
from textual.widgets import TextArea

lang = Language(c_lang()) if tree_sitter else get_language('c')
# 可以从文件中读取语法规则
# from pathlib import Path
# query = (Path(__file__).parent / "c_highlights.scm").read_text()
# 也可以直接嵌入源代码中（字符串中内容同c_highlights.scm）
query = '''\
(identifier) @variable

((identifier) @constant
 (#match? @constant "^[A-Z][A-Z\\d_]*$"))

"break" @keyword
"case" @keyword
"const" @keyword
"continue" @keyword
"default" @keyword
"do" @keyword
"else" @keyword
"enum" @keyword
"extern" @keyword
"for" @keyword
"if" @keyword
"inline" @keyword
"return" @keyword
"sizeof" @keyword
"static" @keyword
"struct" @keyword
"switch" @keyword
"typedef" @keyword
"union" @keyword
"volatile" @keyword
"while" @keyword

"#define" @keyword
"#elif" @keyword
"#else" @keyword
"#endif" @keyword
"#if" @keyword
"#ifdef" @keyword
"#ifndef" @keyword
"#include" @keyword
(preproc_directive) @keyword

"--" @operator
"-" @operator
"-=" @operator
"->" @operator
"=" @operator
"!=" @operator
"*" @operator
"&" @operator
"&&" @operator
"+" @operator
"++" @operator
"+=" @operator
"<" @operator
"==" @operator
">" @operator
"||" @operator

"." @delimiter
";" @delimiter

(string_literal) @string
(system_lib_string) @string

(null) @constant
(number_literal) @number
(char_literal) @number

(field_identifier) @property
(statement_identifier) @label
(type_identifier) @type
(primitive_type) @type
(sized_type_specifier) @type

(call_expression
  function: (identifier) @function)
(call_expression
  function: (field_expression
    field: (field_identifier) @function))
(function_declarator
  declarator: (identifier) @function)
(preproc_function_def
  name: (identifier) @function.special)

(comment) @comment
'''

code = '''\
#include <stdio.h>

int main() {
    printf('Hello World!');
    return 0;
}
'''
class MyApp(App):
    def on_mount(self):
        self.widgets = [
            TextArea.code_editor(text=code)
        ]
        self.mount_all(self.widgets)
        text_area = self.query_one(TextArea)
        text_area.register_language("c", lang, query)
        text_area.language = "c"

if __name__ == '__main__':
    app = MyApp()
    app.run()