hex: Add from_spaced_hex()

tools/evmc/filter_iterator.hpp → include/evmc/filter_iterator.hpp

@@ -14,6 +14,7 @@ inline constexpr bool isspace(char ch) noexcept
     return ch == ' ' || (static_cast<unsigned>(ch) - '\t') < 5;
 }
 
+/// Checks if a character is not a white space.
 inline constexpr bool is_not_space(char ch) noexcept
 {
     return !isspace(ch);
@@ -32,10 +33,19 @@ template <typename BaseIterator,
           bool predicate(typename std::iterator_traits<BaseIterator>::value_type) noexcept>
 struct filter_iterator
 {
+    /// The iterator difference type.
     using difference_type = typename std::iterator_traits<BaseIterator>::difference_type;
+
+    /// The iterator value type.
     using value_type = typename std::iterator_traits<BaseIterator>::value_type;
+
+    /// The iterator pointer type.
     using pointer = typename std::iterator_traits<BaseIterator>::pointer;
+
+    /// The iterator reference type.
     using reference = typename std::iterator_traits<BaseIterator>::reference;
+
+    /// The iterator category.
     using iterator_category = std::input_iterator_tag;
 
 private:
@@ -54,26 +64,32 @@ struct filter_iterator
     }
 
 public:
+    /// The constructor of the base iterator pair.
     constexpr filter_iterator(BaseIterator it, BaseIterator end) noexcept : base{it}, base_end{end}
     {
         forward_to_next_value();
     }
 
+    /// The dereference operator.
     constexpr auto operator*() noexcept
     {
         // We should not read from an input base iterator twice. So the only read is in
         // forward_to_next_value() and here we return the cached value.
         return value;
     }
 
+    /// The increment operator.
     constexpr void operator++() noexcept
     {
         ++base;
         forward_to_next_value();
     }
 
-    constexpr bool operator!=(const filter_iterator& o) noexcept { return base != o.base; }
-    constexpr bool operator==(const filter_iterator& o) noexcept { return base == o.base; }
+    /// The equality operator.
+    constexpr bool operator==(const filter_iterator& o) const noexcept { return base == o.base; }
+
+    /// The inequality operator.
+    constexpr bool operator!=(const filter_iterator& o) const noexcept { return base != o.base; }
 };
 
 /// The input filter iterator which skips whitespace characters from the base input iterator.
@@ -83,6 +99,7 @@ struct skip_space_iterator : filter_iterator<BaseIterator, is_not_space>
     using filter_iterator<BaseIterator, is_not_space>::filter_iterator;
 };
 
+/// Class template argument deduction guide.
 template <typename BaseIterator>
 skip_space_iterator(BaseIterator, BaseIterator) -> skip_space_iterator<BaseIterator>;
 }  // namespace evmc

include/evmc/hex.hpp

@@ -3,8 +3,8 @@
 // Licensed under the Apache License, Version 2.0.
 #pragma once
 
+#include <evmc/filter_iterator.hpp>
 #include <cstdint>
-#include <iterator>
 #include <optional>
 #include <string>
 #include <string_view>
@@ -104,7 +104,6 @@ inline bool validate_hex(std::string_view hex) noexcept
 ///
 /// In case the input is invalid the returned value is std::nullopt.
 /// This can happen if a non-hex digit or odd number of digits is encountered.
-/// Whitespace in the input is ignored.
 inline std::optional<bytes> from_hex(std::string_view hex)
 {
     bytes bs;
@@ -135,4 +134,25 @@ constexpr std::optional<T> from_hex(std::string_view s) noexcept
         return {};
     return r;
 }
+
+/// Decodes hex encoded string to bytes. The whitespace in the input is ignored.
+///
+/// In case the input is invalid the returned value is std::nullopt.
+/// This can happen if a non-hex digit or odd number of digits is encountered.
+/// The whitespace (as defined by std::isspace) in the input is ignored.
+template <typename InputIterator>
+std::optional<bytes> from_spaced_hex(InputIterator begin, InputIterator end) noexcept
+{
+    bytes bs;
+    if (!from_hex(skip_space_iterator{begin, end}, skip_space_iterator{end, end},
+                  std::back_inserter(bs)))
+        return {};
+    return bs;
+}
+
+/// @copydoc from_spaced_hex
+inline std::optional<bytes> from_spaced_hex(std::string_view hex) noexcept
+{
+    return from_spaced_hex(hex.begin(), hex.end());
+}
 }  // namespace evmc

test/compilation/compilation_test.cxx

@@ -12,6 +12,7 @@
 #include <evmc/mocked_host.hpp>
 #include <evmc/utils.h>
 #include <evmc/hex.hpp>
+#include <evmc/filter_iterator.hpp>
 
 // Include again to check if headers have proper include guards.
 #include <evmc/evmc.h>
@@ -22,3 +23,4 @@
 #include <evmc/mocked_host.hpp>
 #include <evmc/utils.h>
 #include <evmc/hex.hpp>
+#include <evmc/filter_iterator.hpp>

test/unittests/filter_iterator_test.cpp

@@ -2,7 +2,7 @@
 // Copyright 2022 The EVMC Authors.
 // Licensed under the Apache License, Version 2.0.
 
-#include <tools/evmc/filter_iterator.hpp>
+#include <evmc/filter_iterator.hpp>
 #include <gtest/gtest.h>
 #include <cctype>
 

test/unittests/hex_test.cpp

@@ -3,7 +3,6 @@
 // Licensed under the Apache License, Version 2.0.
 
 #include <evmc/hex.hpp>
-#include <tools/evmc/filter_iterator.hpp>
 #include <gtest/gtest.h>
 
 using namespace evmc;
@@ -82,21 +81,12 @@ TEST(hex, validate_hex)
     EXPECT_FALSE(validate_hex("WXYZ"));
 }
 
-TEST(hex, from_hex_skip_space)
+TEST(hex, from_spaced_hex)
 {
-    // Combine from_hex with skip_space_iterator.
-    static constexpr auto from_hex_skip_space = [](std::string_view hex) {
-        bytes out;
-        const auto status =
-            from_hex(skip_space_iterator{hex.begin(), hex.end()},
-                     skip_space_iterator{hex.end(), hex.end()}, std::back_inserter(out));
-        EXPECT_TRUE(status);
-        return out;
-    };
-    EXPECT_EQ(from_hex_skip_space("0x010203"), (bytes{0x01, 0x02, 0x03}));
-    EXPECT_EQ(from_hex_skip_space("0x 010203 "), (bytes{0x01, 0x02, 0x03}));
-    EXPECT_EQ(from_hex_skip_space(" 0 x 0 1 0 2 0 3 "), (bytes{0x01, 0x02, 0x03}));
-    EXPECT_EQ(from_hex_skip_space("\f 0\r x  0  1\t 0  2 \v0  3 \n"), (bytes{0x01, 0x02, 0x03}));
+    EXPECT_EQ(from_spaced_hex("0x010203"), (bytes{0x01, 0x02, 0x03}));
+    EXPECT_EQ(from_spaced_hex("0x 010203 "), (bytes{0x01, 0x02, 0x03}));
+    EXPECT_EQ(from_spaced_hex(" 0 x 0 1 0 2 0 3 "), (bytes{0x01, 0x02, 0x03}));
+    EXPECT_EQ(from_spaced_hex("\f 0\r x  0  1\t 0  2 \v0  3 \n"), (bytes{0x01, 0x02, 0x03}));
 }
 
 TEST(hex, from_hex_to_custom_type)

tools/evmc/CMakeLists.txt

@@ -5,7 +5,7 @@
 hunter_add_package(CLI11)
 find_package(CLI11 REQUIRED)
 
-add_executable(evmc-tool main.cpp filter_iterator.hpp)
+add_executable(evmc-tool main.cpp)
 add_executable(evmc::tool ALIAS evmc-tool)
 set_target_properties(evmc-tool PROPERTIES OUTPUT_NAME evmc)
 set_source_files_properties(main.cpp PROPERTIES

tools/evmc/main.cpp

@@ -1,8 +1,7 @@
 // EVMC: Ethereum Client-VM Connector API.
-// Copyright 2019-2020 The EVMC Authors.
+// Copyright 2019 The EVMC Authors.
 // Licensed under the Apache License, Version 2.0.
 
-#include "filter_iterator.hpp"
 #include <CLI/CLI.hpp>
 #include <evmc/hex.hpp>
 #include <evmc/loader.h>
@@ -20,13 +19,11 @@ evmc::bytes load_from_hex(const std::string& str)
     {
         const auto path = str.substr(1);
         std::ifstream file{path};
-        const std::istreambuf_iterator<char> file_begin{file};
-        const std::istreambuf_iterator<char> file_end;
-        evmc::bytes out;
-        if (!evmc::from_hex(evmc::skip_space_iterator{file_begin, file_end},
-                            evmc::skip_space_iterator{file_end, file_end}, std::back_inserter(out)))
+        auto out = evmc::from_spaced_hex(std::istreambuf_iterator<char>{file},
+                                         std::istreambuf_iterator<char>{});
+        if (!out)
             throw std::invalid_argument{"invalid hex in " + path};
-        return out;
+        return out.value();
     }
 
     return evmc::from_hex(str).value();  // Should be validated already.