Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibCore/CArgsParser.cpp

@@ -0,0 +1,237 @@
+#include "CArgsParser.h"
+#include <AK/StringBuilder.h>
+
+#include <stdio.h>
+
+bool CArgsParserResult::is_present(const String& arg_name) const
+{
+    return m_args.contains(arg_name);
+}
+
+String CArgsParserResult::get(const String& arg_name) const
+{
+    return m_args.get(arg_name);
+}
+
+const Vector<String>& CArgsParserResult::get_single_values() const
+{
+    return m_single_values;
+}
+
+CArgsParser::Arg::Arg(const String& name, const String& description, bool required)
+    : name(name)
+    , description(description)
+    , required(required)
+{
+}
+
+CArgsParser::Arg::Arg(const String& name, const String& value_name, const String& description, bool required)
+    : name(name)
+    , description(description)
+    , value_name(value_name)
+    , required(required)
+{
+}
+
+CArgsParser::CArgsParser(const String& program_name)
+    : m_program_name(program_name)
+    , m_prefix("-")
+{
+}
+
+CArgsParserResult CArgsParser::parse(int argc, char** argv)
+{
+    CArgsParserResult res;
+
+    // We should have at least one parameter
+    if (argc < 2)
+        return {};
+
+    // We parse the first parameter at the index 1
+    if (parse_next_param(1, argv, argc - 1, res) != 0)
+        return {};
+
+    if (!check_required_args(res))
+        return {};
+
+    return res;
+}
+
+int CArgsParser::parse_next_param(int index, char** argv, const int params_left, CArgsParserResult& res)
+{
+    if (params_left == 0)
+        return 0;
+
+    String param = argv[index];
+
+    // We check if the prefix is found at the beginning of the param name
+    if (is_param_valid(param)) {
+        auto prefix_length = m_prefix.length();
+        String param_name = param.substring(prefix_length, param.length() - prefix_length);
+
+        auto arg = m_args.find(param_name);
+        if (arg == m_args.end()) {
+            printf("Unknown arg \"");
+            if (!param_name.is_null())
+                printf("%s", param_name.characters());
+            printf("\"\n");
+            return -1;
+        }
+
+        // If this parameter must be followed by a value, we look for it
+        if (!arg->value.value_name.is_null()) {
+            if (params_left < 1) {
+                printf("Missing value for argument %s\n", arg->value.name.characters());
+                return -1;
+            }
+
+            String next = String(argv[index + 1]);
+
+            if (is_param_valid(next)) {
+                printf("Missing value for argument %s\n", arg->value.name.characters());
+                return -1;
+            }
+
+            res.m_args.set(arg->value.name, next);
+            return parse_next_param(index + 2, argv, params_left - 2, res);
+        }
+
+        // Single argument, not followed by a value
+        res.m_args.set(arg->value.name, "");
+        return parse_next_param(index + 1, argv, params_left - 1, res);
+    }
+
+    // Else, it's a value alone, a file name parameter for example
+    res.m_single_values.append(param);
+    return parse_next_param(index + 1, argv, params_left - 1, res);
+}
+
+bool CArgsParser::is_param_valid(const String& param_name)
+{
+    return param_name.substring(0, m_prefix.length()) == m_prefix;
+}
+
+bool CArgsParser::check_required_args(const CArgsParserResult& res)
+{
+    for (auto& it : m_args) {
+        if (it.value.required) {
+            if (!res.is_present(it.value.name))
+                return false;
+        }
+    }
+
+    int required_arguments = 0;
+    for (const auto& a : m_single_args) {
+        if (a.required) {
+            required_arguments++;
+        }
+    }
+
+    if (required_arguments != 0) {
+        if (res.m_single_values.size() < required_arguments)
+            return false;
+    }
+
+    return true;
+}
+
+void CArgsParser::add_required_arg(const String& name, const String& description)
+{
+    m_args.set(name, Arg(name, description, true));
+}
+
+void CArgsParser::add_required_arg(const String& name, const String& value_name, const String& description)
+{
+    m_args.set(name, Arg(name, value_name, description, true));
+}
+
+void CArgsParser::add_arg(const String& name, const String& description)
+{
+    m_args.set(name, Arg(name, description, false));
+}
+
+void CArgsParser::add_arg(const String& name, const String& value_name, const String& description)
+{
+    m_args.set(name, Arg(name, value_name, description, false));
+}
+
+void CArgsParser::add_single_value(const String& name)
+{
+    m_single_args.append(SingleArg { name, false });
+}
+
+void CArgsParser::add_required_single_value(const String& name)
+{
+    if (m_single_args.size() != 0) {
+        // adding required arguments after non-required arguments would be nonsensical
+        ASSERT(m_single_args.last().required);
+    }
+    m_single_args.append(SingleArg { name, true });
+}
+
+String CArgsParser::get_usage() const
+{
+    StringBuilder sb;
+
+    sb.append("usage : ");
+    sb.append(m_program_name);
+    sb.append(" ");
+
+    for (auto& it : m_args) {
+        if (it.value.required)
+            sb.append("<");
+        else
+            sb.append("[");
+
+        sb.append(m_prefix);
+        sb.append(it.value.name);
+
+        if (!it.value.value_name.is_null()) {
+            sb.append(" ");
+            sb.append(it.value.value_name);
+        }
+
+        if (it.value.required)
+            sb.append("> ");
+        else
+            sb.append("] ");
+    }
+
+    for (auto& arg : m_single_args) {
+        if (arg.required)
+            sb.append("<");
+        else
+            sb.append("[");
+
+        sb.append(arg.name);
+
+        if (arg.required)
+            sb.append("> ");
+        else
+            sb.append("] ");
+    }
+
+    sb.append("\n");
+
+    for (auto& it : m_args) {
+        sb.append("    ");
+        sb.append(m_prefix);
+        sb.append(it.value.name);
+
+        if (!it.value.value_name.is_null()) {
+            sb.append(" ");
+            sb.append(it.value.value_name);
+        }
+
+        sb.append(" : ");
+        sb.append(it.value.description);
+        sb.append("\n");
+    }
+
+    return sb.to_string();
+}
+
+void CArgsParser::print_usage() const
+{
+    printf("%s\n", get_usage().characters());
+}