poafloc

commit 2a2b4adf380a3a90c6a04413958986b622219bcf
parent 4cda95db89f7f2106d3f7a9c0374c0d1490402db
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Sat,  8 Jun 2024 23:35:46 +0200

Change interface to use 1 static function

* Use static function as an entry point
* Proveded callback accepts Parser* for interfacing with the parser

Diffstat:
M
args.hpp
 | 
35
+++++++++++++++++++++--------------
M
demo.cpp
 | 
22
+++++++++-------------

2 files changed, 30 insertions(+), 27 deletions(-)
diff --git a/args.hpp b/args.hpp
@@ -38,7 +38,7 @@ class Parser {
     };
 
     struct argp_t {
-        using parse_f = int (*)(int key, const char *arg, void *input);
+        using parse_f = int (*)(int key, const char *arg, Parser *parser);
 
         const option_t *options;
         const parse_f parser;
@@ -46,7 +46,15 @@ class Parser {
         const char *message;
     };
 
-    Parser(argp_t *argp) : argp(argp) {
+    static int parse(argp_t *argp, int argc, char *argv[], void *input) {
+        Parser parser(input, argp);
+        return parser.parse(argc, argv, &parser);
+    }
+
+    void *input;
+
+  private:
+    Parser(void *input, argp_t *argp) : input(input), argp(argp) {
         bool hidden = false;
         int group = 0, key_last = 0;
 
@@ -128,11 +136,11 @@ class Parser {
     int parse(int argc, char *argv[], void *input) {
         int args = 0, i;
 
-        argp->parser(Key::INIT, 0, input);
+        argp->parser(Key::INIT, 0, this);
 
         for (i = 1; i < argc; i++) {
             if (argv[i][0] != '-') {
-                argp->parser(Key::ARG, argv[i], input);
+                argp->parser(Key::ARG, argv[i], this);
                 args++;
                 continue;
             }
@@ -164,7 +172,7 @@ class Parser {
                         }
                     }
 
-                    argp->parser(key, arg, input);
+                    argp->parser(key, arg, this);
 
                     // if last option required argument we are done
                     if (arg) break;
@@ -204,40 +212,39 @@ class Parser {
                     }
                 }
 
-                argp->parser(key, arg, input);
+                argp->parser(key, arg, this);
             }
         }
 
         // parse rest argv as normal arguments
         for (i = i + 1; i < argc; i++) {
-            argp->parser(Key::ARG, argv[i], input);
+            argp->parser(Key::ARG, argv[i], this);
             args++;
         }
 
-        if (!args) argp->parser(Key::NO_ARGS, 0, input);
+        if (!args) argp->parser(Key::NO_ARGS, 0, this);
 
-        argp->parser(Key::END, 0, input);
-        argp->parser(Key::SUCCESS, 0, input);
+        argp->parser(Key::END, 0, this);
+        argp->parser(Key::SUCCESS, 0, this);
 
         return 0;
 
     unknown:
         std::cerr << std::format("unknown option {}\n", argv[i]);
-        argp->parser(Key::ERROR, 0, input);
+        argp->parser(Key::ERROR, 0, this);
         return 1;
 
     missing:
         std::cerr << std::format("option {} missing a value\n", argv[i]);
-        argp->parser(Key::ERROR, 0, input);
+        argp->parser(Key::ERROR, 0, this);
         return 2;
 
     excess:
         std::cerr << std::format("option {} don't require a value\n", argv[i]);
-        argp->parser(Key::ERROR, 0, input);
+        argp->parser(Key::ERROR, 0, this);
         return 3;
     }
 
-  private:
     class trie_t {
       public:
         ~trie_t() noexcept {
diff --git a/demo.cpp b/demo.cpp
@@ -15,8 +15,8 @@ struct arguments_t {
     std::vector<const char *> args;
 };
 
-int parse_opt(int key, const char *arg, void *input) {
-    auto arguments = (arguments_t *)input;
+int parse_opt(int key, const char *arg, Parser *parser) {
+    auto arguments = (arguments_t *)parser->input;
 
     switch (key) {
     case 777: arguments->debug = true; break;
@@ -45,7 +45,7 @@ static const Parser::option_t options[] = {
     {           0,    0,      0,               0,                 "Program mode", 1},
     {"relocatable", 'r',      0,               0, "Output in relocatable format"},
     {        "hex", 'h',      0,               0,         "Output in hex format"},
-    {"hexadecimal",   0,      0, ALIAS | HIDDEN},
+    {"hexadecimal",   0,      0,  ALIAS | HIDDEN},
     {            0,   0,      0,               0,               "For developers", 4},
     {      "debug", 777,      0,               0,        "Enable debugging mode"},
     {            0,   0,      0,               0,                 "Input/output", 3},
@@ -57,17 +57,12 @@ static const Parser::option_t options[] = {
 // clang-format on
 
 int main(int argc, char *argv[]) {
-    Parser::argp_t argp = {
-        options,
-        parse_opt,
-        "doc string\nother usage",
-        "First half of the message\vsecond half of the message"
-    };
-    Parser parser(&argp);
-
     arguments_t arguments;
+    Parser::argp_t argp = {
+        options, parse_opt, "doc string\nother usage",
+        "First half of the message\vsecond half of the message"};
 
-    if (parser.parse(argc, argv, &arguments)) {
+    if (Parser::parse(&argp, argc, argv, &arguments)) {
         error("There was an error while parsing arguments");
         return 1;
     }
@@ -81,7 +76,8 @@ int main(int argc, char *argv[]) {
     std::cout << "\t relocatable: " << arguments.relocatable << std::endl;
 
     std::cout << "\t args: ";
-    for (const auto &arg : arguments.args) std::cout << arg << " ";
+    for (const auto &arg : arguments.args)
+        std::cout << arg << " ";
     std::cout << std::endl;
 
     return 0;