Opt class for positional argument handling

Added support for positional arguments `MODEL` and `PROMPT`.

Signed-off-by: Eric Curtin <[email protected]>

Author: ericcurtin

examples/run/run.cpp

@@ -17,96 +17,102 @@
 
 typedef std::unique_ptr<char[]> char_array_ptr;
 
-struct Argument {
-    std::string flag;
-    std::string help_text;
-};
-
-struct Options {
-    std::string model_path, prompt_non_interactive;
-    int ngl = 99;
-    int n_ctx = 2048;
-};
+class Opt {
+  public:
+    int init_opt(int argc, const char ** argv) {
+        construct_help_str_();
+        // Parse arguments
+        if (parse(argc, argv)) {
+            fprintf(stderr, "Error: Failed to parse arguments.\n");
+            help();
+            return 1;
+        }
 
-class ArgumentParser {
-   public:
-    ArgumentParser(const char * program_name) : program_name(program_name) {}
+        // If help is requested, show help and exit
+        if (help_) {
+            help();
+            return 2;
+        }
 
-    void add_argument(const std::string & flag, std::string & var, const std::string & help_text = "") {
-        string_args[flag] = &var;
-        arguments.push_back({flag, help_text});
+        return 0;  // Success
     }
 
-    void add_argument(const std::string & flag, int & var, const std::string & help_text = "") {
-        int_args[flag] = &var;
-        arguments.push_back({flag, help_text});
+    const char *             model_ = nullptr;
+    std::string              prompt_;
+    int                      context_size_ = 2048, ngl_ = 0;
+
+  private:
+    std::string help_str_;
+    bool        help_ = false;
+
+    void construct_help_str_() {
+        help_str_ =
+            "Description:\n"
+            "  Runs a llm\n"
+            "\n"
+            "Usage:\n"
+            "  llama-run [options] MODEL [PROMPT]\n"
+            "\n"
+            "Options:\n"
+            "  -c, --context-size <value>\n"
+            "      Context size (default: " +
+            std::to_string(context_size_);
+        help_str_ +=
+            ")\n"
+            "  -n, --ngl <value>\n"
+            "      Number of GPU layers (default: " +
+            std::to_string(ngl_);
+        help_str_ +=
+            ")\n"
+            "  -h, --help\n"
+            "      Show help message\n"
+            "\n"
+            "Examples:\n"
+            "  llama-run ~/.local/share/ramalama/models/ollama/smollm\\:135m\n"
+            "  llama-run --ngl 99 ~/.local/share/ramalama/models/ollama/smollm\\:135m\n"
+            "  llama-run --ngl 99 ~/.local/share/ramalama/models/ollama/smollm\\:135m Hello World\n";
     }
 
     int parse(int argc, const char ** argv) {
+        if (parse_arguments(argc, argv) || !model_) {
+            return 1;
+        }
+
+        return 0;
+    }
+
+    int parse_arguments(int argc, const char ** argv) {
+        int positional_args_i = 0;
         for (int i = 1; i < argc; ++i) {
-            std::string arg = argv[i];
-            if (string_args.count(arg)) {
-                if (i + 1 < argc) {
-                    *string_args[arg] = argv[++i];
-                } else {
-                    fprintf(stderr, "error: missing value for %s\n", arg.c_str());
-                    print_usage();
+            if (std::strcmp(argv[i], "-c") == 0 || std::strcmp(argv[i], "--context-size") == 0) {
+                if (i + 1 >= argc) {
                     return 1;
                 }
-            } else if (int_args.count(arg)) {
-                if (i + 1 < argc) {
-                    if (parse_int_arg(argv[++i], *int_args[arg]) != 0) {
-                        fprintf(stderr, "error: invalid value for %s: %s\n", arg.c_str(), argv[i]);
-                        print_usage();
-                        return 1;
-                    }
-                } else {
-                    fprintf(stderr, "error: missing value for %s\n", arg.c_str());
-                    print_usage();
+
+                context_size_ = std::atoi(argv[++i]);
+            } else if (std::strcmp(argv[i], "-n") == 0 || std::strcmp(argv[i], "--ngl") == 0) {
+                if (i + 1 >= argc) {
                     return 1;
                 }
+
+                ngl_ = std::atoi(argv[++i]);
+            } else if (std::strcmp(argv[i], "-h") == 0 || std::strcmp(argv[i], "--help") == 0) {
+                help_ = true;
+            } else if (!positional_args_i) {
+                ++positional_args_i;
+                model_ = argv[i];
+            } else if (positional_args_i == 1) {
+                ++positional_args_i;
+                prompt_ = argv[i];
             } else {
-                fprintf(stderr, "error: unrecognized argument %s\n", arg.c_str());
-                print_usage();
-                return 1;
+                prompt_ += " " + std::string(argv[i]);
             }
         }
 
-        if (string_args["-m"]->empty()) {
-            fprintf(stderr, "error: -m is required\n");
-            print_usage();
-            return 1;
-        }
-
         return 0;
     }
 
-   private:
-    const char * program_name;
-    std::unordered_map<std::string, std::string *> string_args;
-    std::unordered_map<std::string, int *> int_args;
-    std::vector<Argument> arguments;
-
-    int parse_int_arg(const char * arg, int & value) {
-        char * end;
-        const long val = std::strtol(arg, &end, 10);
-        if (*end == '\0' && val >= INT_MIN && val <= INT_MAX) {
-            value = static_cast<int>(val);
-            return 0;
-        }
-        return 1;
-    }
-
-    void print_usage() const {
-        printf("\nUsage:\n");
-        printf("  %s [OPTIONS]\n\n", program_name);
-        printf("Options:\n");
-        for (const auto & arg : arguments) {
-            printf("  %-10s %s\n", arg.flag.c_str(), arg.help_text.c_str());
-        }
-
-        printf("\n");
-    }
+    void help() const { printf("%s", help_str_.c_str()); }
 };
 
 class LlamaData {
@@ -116,13 +122,13 @@ class LlamaData {
     llama_context_ptr context;
     std::vector<llama_chat_message> messages;
 
-    int init(const Options & opt) {
-        model = initialize_model(opt.model_path, opt.ngl);
+    int init(const Opt & opt) {
+        model = initialize_model(opt.model_, opt.ngl_);
         if (!model) {
             return 1;
         }
 
-        context = initialize_context(model, opt.n_ctx);
+        context = initialize_context(model, opt.context_size_);
         if (!context) {
             return 1;
         }
@@ -273,19 +279,6 @@ static int generate(LlamaData & llama_data, const std::string & prompt, std::str
     return 0;
 }
 
-static int parse_arguments(const int argc, const char ** argv, Options & opt) {
-    ArgumentParser parser(argv[0]);
-    parser.add_argument("-m", opt.model_path, "model");
-    parser.add_argument("-p", opt.prompt_non_interactive, "prompt");
-    parser.add_argument("-c", opt.n_ctx, "context_size");
-    parser.add_argument("-ngl", opt.ngl, "n_gpu_layers");
-    if (parser.parse(argc, argv)) {
-        return 1;
-    }
-
-    return 0;
-}
-
 static int read_user_input(std::string & user) {
     std::getline(std::cin, user);
     return user.empty();  // Indicate an error or empty input
@@ -382,17 +375,20 @@ static std::string read_pipe_data() {
 }
 
 int main(int argc, const char ** argv) {
-    Options opt;
-    if (parse_arguments(argc, argv, opt)) {
+    Opt       opt;
+    const int opt_ret = opt.init_opt(argc, argv);
+    if (opt_ret == 2) {
+        return 0;
+    } else if (opt_ret) {
         return 1;
     }
 
     if (!is_stdin_a_terminal()) {
-        if (!opt.prompt_non_interactive.empty()) {
-            opt.prompt_non_interactive += "\n\n";
+        if (!opt.prompt_.empty()) {
+            opt.prompt_ += "\n\n";
         }
 
-        opt.prompt_non_interactive += read_pipe_data();
+        opt.prompt_ += read_pipe_data();
     }
 
     llama_log_set(log_callback, nullptr);
@@ -401,7 +397,7 @@ int main(int argc, const char ** argv) {
         return 1;
     }
 
-    if (chat_loop(llama_data, opt.prompt_non_interactive)) {
+    if (chat_loop(llama_data, opt.prompt_)) {
         return 1;
     }