feat: create args view with positionals

ggabriel96 · Feb 3, 2025 · 717cfcd · 717cfcd
1 parent 4ea81b6
commit 717cfcd
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Showing 3 changed files with 174 additions and 71 deletions.
diff --git a/examples/main.cpp b/examples/main.cpp
@@ -14,6 +14,8 @@ int main(int argc, char const *argv[]) {
                .Flg<"disable-content-trust">({.help = "Skip image verification"})
                .Flg<"quiet", "q">({.help = "Supress verbose output"});
 
+  parse(p, std::span<char const *>{argv, argc});
+
   // p.SetValue<"age">(28);
   // auto age = p.GetValue<"name">();
   // fmt::print("name: [{}]\n", age.value_or(std::string()));

diff --git a/include/experimental/parsing.hpp b/include/experimental/parsing.hpp
@@ -3,9 +3,11 @@
 
 #include <any>
 #include <map>
+#include <print>
 #include <span>
 #include <string>
 #include <string_view>
+#include <vector>
 
 #include "converters.hpp"
 #include "exceptions.hpp"
@@ -14,6 +16,10 @@
 #include "experimental/string_list.hpp"
 #include "experimental/type_list.hpp"
 
+// +---------------------+
+// |      fwd decls      |
+// +---------------------+
+
 struct ParsedOption {
   std::string_view name;
   // no string and empty string mean different things here
@@ -30,4 +36,170 @@ constexpr std::string_view get_if_short_flags(std::string_view const) noexcept;
 constexpr std::string_view get_if_long_flag(std::string_view const) noexcept;
 constexpr ParsedOption try_parse_option(std::string_view const) noexcept;
 
+// +-----------------------+
+// |   main parsing code   |
+// +-----------------------+
+
+struct ArgsView {
+  std::vector<std::string_view> positionals;
+  std::map<std::string_view, std::vector<std::string_view>> options;
+};
+
+struct ArgMap {
+  std::string_view exec_path{};
+  std::map<std::string_view, std::any> args;
+
+  std::any operator[](std::string_view name) const {
+    if (!args.contains(name)) throw opzioni::ArgumentNotFound(name);
+    return args.at(name);
+  }
+
+  template <typename T>
+  T as(std::string_view name) const {
+    auto const arg = (*this)[name];
+    return std::any_cast<T>(arg);
+  }
+
+  bool has(std::string_view name) const noexcept { return args.contains(name); }
+
+  auto size() const noexcept { return this->args.size(); }
+};
+
+template <typename...>
+struct ArgParser;
+
+template <fixed_string... ArgNames, typename... ArgTypes>
+struct ArgParser<StringList<ArgNames...>, TypeList<ArgTypes...>> {
+
+  std::string_view exec_path{};
+  std::map<std::string_view, std::any> args;
+  Program<StringList<ArgNames...>, TypeList<ArgTypes...>> const &program;
+
+  ArgParser(Program<StringList<ArgNames...>, TypeList<ArgTypes...>> const &program) : program(program) {}
+
+  ArgMap operator()(std::span<char const *> args) {
+    ArgMap map;
+    map.exec_path = args[0];
+    return map;
+  }
+
+  auto get_args_view(std::span<char const *> args) {
+    ArgsView view;
+    if (args.size() > 0) {
+      std::size_t current_positional_idx = 0;
+      for (std::size_t index = 1; index < args.size();) {
+        auto const arg = std::string_view(args[index]);
+        if (is_dash_dash(arg)) {
+          // +1 to ignore the dash-dash
+          auto const rest = args.subspan(index + 1);
+          view.positionals.reserve(view.positionals.size() + rest.size());
+          for (auto const &str : rest) {
+            view.positionals.emplace_back(str);
+          }
+          current_positional_idx += rest.size();
+          index = args.size();
+        // } else if (auto cmd = is_command(program, arg); cmd != nullptr) {
+        //   index += assign_command(map, args.subspan(index), *cmd);
+        } else if (looks_positional(arg)) {
+          view.positionals.emplace_back(arg);
+          ++current_positional_idx;
+          ++index;
+        // } else if (auto const flags = is_short_flags(program, arg); !flags.empty()) {
+        //   index += assign_many_flags(program, map, flags);
+        // } else if (auto const flag = is_long_flag(program, arg); !flag.empty()) {
+        //   index += assign_flag(program, map, flag);
+        // } else if (auto const option = is_option(program, arg); option.has_value()) {
+        //   index += assign_option(program, map, args.subspan(index), *option);
+        } else {
+          throw opzioni::UnknownArgument(arg);
+        }
+      }
+    }
+    return view;
+  }
+};
+
+template <fixed_string... ArgNames, typename... ArgTypes>
+auto parse(Program<StringList<ArgNames...>, TypeList<ArgTypes...>> const &program, std::span<char const *> args) {
+  auto result  = ArgParser<StringList<ArgNames...>, TypeList<ArgTypes...>>(program);
+  auto const i = result.get_args_view(args);
+  std::print("positionals:\n");
+  for (auto &&p : i.positionals) {
+    std::print("{} ", p);
+  }
+  std::print("\n");
+  // auto map = parse_args(program, args);
+  // check_contains_required(program, map);
+  return result;
+}
+
+// +---------------------+
+// |   parsing helpers   |
+// +---------------------+
+
+constexpr bool is_dash_dash(std::string_view const whole_arg) noexcept {
+  return whole_arg.length() == 2 && whole_arg[0] == '-' && whole_arg[1] == '-';
+}
+
+constexpr bool looks_positional(std::string_view const whole_arg) noexcept {
+  auto const num_of_dashes = whole_arg.find_first_not_of('-');
+  return num_of_dashes == 0 || (whole_arg.length() == 1 && num_of_dashes == std::string_view::npos);
+}
+
+constexpr std::string_view get_if_short_flags(std::string_view const whole_arg) noexcept {
+  auto const num_of_dashes = whole_arg.find_first_not_of('-');
+  auto const flags = whole_arg.substr(1);
+  if (num_of_dashes == 1 && flags.length() >= 1)
+    return flags;
+  return {};
+}
+
+constexpr std::string_view get_if_long_flag(std::string_view const whole_arg) noexcept {
+  auto const name = whole_arg.substr(2);
+  auto const num_of_dashes = whole_arg.find_first_not_of('-');
+  if (num_of_dashes == 2 && name.length() >= 2)
+    return name;
+  return {};
+}
+
+constexpr ParsedOption try_parse_option(std::string_view const whole_arg) noexcept {
+  auto const num_of_dashes = whole_arg.find_first_not_of('-');
+  auto const eq_idx = whole_arg.find('=', num_of_dashes);
+  bool const has_equals = eq_idx != std::string_view::npos;
+  if (num_of_dashes == 1) {
+    // short option, e.g. `-O`
+    auto const name = whole_arg.substr(1, 1);
+    if (has_equals) {
+      if (whole_arg.length() > 3) {
+        // has equals followed by some value, e.g. `-O=2`
+        return {name, whole_arg.substr(3)};
+      }
+      // should this `-O=` be handled like this?
+      return {name, ""};
+    }
+
+    if (whole_arg.length() > 2) {
+      // only followed by some value, e.g. `-O2`
+      return {name, whole_arg.substr(2)};
+    }
+
+    // case left: has no value (next CLI argument could be it)
+    return {name, std::nullopt};
+  }
+
+  if (num_of_dashes == 2 && whole_arg.length() > 3) {
+    // long option, e.g. `--name`
+    if (has_equals) {
+      auto const name = whole_arg.substr(2, eq_idx - 2);
+      auto const value = whole_arg.substr(eq_idx + 1);
+      return {name, value};
+    }
+    // has no value (long options cannot have "glued" values like `-O2`; next CLI argument could be it)
+    return {whole_arg.substr(2), std::nullopt};
+  }
+
+  // not an option
+  return {"", std::nullopt};
+}
+
 #endif
diff --git a/src/experimental/parsing.cpp b/src/experimental/parsing.cpp
@@ -1,72 +1 @@
-#include <format>
-
 #include "experimental/parsing.hpp"
-
-// +---------------------+
-// |   parsing helpers   |
-// +---------------------+
-
-constexpr bool is_dash_dash(std::string_view const whole_arg) noexcept {
-  return whole_arg.length() == 2 && whole_arg[0] == '-' && whole_arg[1] == '-';
-}
-
-constexpr bool looks_positional(std::string_view const whole_arg) noexcept {
-  auto const num_of_dashes = whole_arg.find_first_not_of('-');
-  return num_of_dashes == 0 || (whole_arg.length() == 1 && num_of_dashes == std::string_view::npos);
-}
-
-constexpr std::string_view get_if_short_flags(std::string_view const whole_arg) noexcept {
-  auto const num_of_dashes = whole_arg.find_first_not_of('-');
-  auto const flags = whole_arg.substr(1);
-  if (num_of_dashes == 1 && flags.length() >= 1)
-    return flags;
-  return {};
-}
-
-constexpr std::string_view get_if_long_flag(std::string_view const whole_arg) noexcept {
-  auto const name = whole_arg.substr(2);
-  auto const num_of_dashes = whole_arg.find_first_not_of('-');
-  if (num_of_dashes == 2 && name.length() >= 2)
-    return name;
-  return {};
-}
-
-constexpr ParsedOption try_parse_option(std::string_view const whole_arg) noexcept {
-  auto const num_of_dashes = whole_arg.find_first_not_of('-');
-  auto const eq_idx = whole_arg.find('=', num_of_dashes);
-  bool const has_equals = eq_idx != std::string_view::npos;
-  if (num_of_dashes == 1) {
-    // short option, e.g. `-O`
-    auto const name = whole_arg.substr(1, 1);
-    if (has_equals) {
-      if (whole_arg.length() > 3) {
-        // has equals followed by some value, e.g. `-O=2`
-        return {name, whole_arg.substr(3)};
-      }
-      // should this `-O=` be handled like this?
-      return {name, ""};
-    }
-
-    if (whole_arg.length() > 2) {
-      // only followed by some value, e.g. `-O2`
-      return {name, whole_arg.substr(2)};
-    }
-
-    // case left: has no value (next CLI argument could be it)
-    return {name, std::nullopt};
-  }
-
-  if (num_of_dashes == 2 && whole_arg.length() > 3) {
-    // long option, e.g. `--name`
-    if (has_equals) {
-      auto const name = whole_arg.substr(2, eq_idx - 2);
-      auto const value = whole_arg.substr(eq_idx + 1);
-      return {name, value};
-    }
-    // has no value (long options cannot have "glued" values like `-O2`; next CLI argument could be it)
-    return {whole_arg.substr(2), std::nullopt};
-  }
-
-  // not an option
-  return {"", std::nullopt};
-}