add new way to make a GenSpec based on a textual description

3 files changed, 104 insertions, 1 deletions

diff --git a/eval/src/tests/eval/gen_spec/gen_spec_test.cpp b/eval/src/tests/eval/gen_spec/gen_spec_test.cpp
index 9d8eb419a67..30ef42d7ebb 100644
--- a/eval/src/tests/eval/gen_spec/gen_spec_test.cpp
+++ b/eval/src/tests/eval/gen_spec/gen_spec_test.cpp
@@ -32,11 +32,13 @@ TEST(DimSpecTest, mapped_dimension) {
 TEST(DimSpecTest, simple_dictionary_creation) {
     auto dict = DimSpec::make_dict(5, 1, "");
     std::vector<vespalib::string> expect = {"0", "1", "2", "3", "4"};
+    EXPECT_EQ(dict, expect);
 }
 
 TEST(DimSpecTest, advanced_dictionary_creation) {
     auto dict = DimSpec::make_dict(5, 3, "str_");
     std::vector<vespalib::string> expect = {"str_0", "str_3", "str_6", "str_9", "str_12"};
+    EXPECT_EQ(dict, expect);
 }
 
 //-----------------------------------------------------------------------------
@@ -234,4 +236,24 @@ TEST(GenSpecTest, gen_spec_can_be_implicitly_converted_to_tensor_spec) {
 
 //-----------------------------------------------------------------------------
 
+TEST(GenSpecFromDescTest, dim_spec_and_gen_spec_can_be_created_from_desc) {
+    // 'a2b3#7c5#'
+    auto expect = GenSpec().idx("a", 2).map("b", 3, 7).map("c", 5).gen();
+    auto dim_desc = GenSpec().desc("a2").desc("b3#7").desc("c5#").gen();
+    auto gen_desc = GenSpec::from_desc("a2b3#7c5#").gen();
+    EXPECT_EQ(dim_desc, expect);
+    EXPECT_EQ(gen_desc, expect);
+}
+
+TEST(GenSpecFromDescTest, multi_character_sizes_work) {
+    // 'a13b1'
+    auto expect = GenSpec().idx("a", 13).idx("b", 1).gen();
+    auto dim_desc = GenSpec().desc("a13").desc("b1").gen();
+    auto gen_desc = GenSpec::from_desc("a13b1").gen();
+    EXPECT_EQ(dim_desc, expect);
+    EXPECT_EQ(gen_desc, expect);
+}
+
+//-----------------------------------------------------------------------------
+
 GTEST_MAIN_RUN_ALL_TESTS()
diff --git a/eval/src/vespa/eval/eval/test/gen_spec.cpp b/eval/src/vespa/eval/eval/test/gen_spec.cpp
index a308cbeff46..87e49c376d1 100644
--- a/eval/src/vespa/eval/eval/test/gen_spec.cpp
+++ b/eval/src/vespa/eval/eval/test/gen_spec.cpp
@@ -53,6 +53,68 @@ DimSpec::make_dict(size_t size, size_t stride, const vespalib::string &prefix)
     return dict;
 }
 
+// 'a2' -> DimSpec("a", 2);
+// 'b2#' -> DimSpec("b", make_dict(2, 1, ""));
+// 'c2#3' -> DimSpec("c", make_dict(2, 3, ""));
+DimSpec
+DimSpec::from_desc(const vespalib::string &desc)
+{
+    size_t idx = 0;
+    vespalib::string name;
+    auto is_num = [](char c) { return ((c >= '0') && (c <= '9')); };
+    auto as_num = [](char c) { return size_t(c - '0'); };
+    auto is_map_tag = [](char c) { return (c == '#'); };
+    auto is_dim_name = [](char c) { return ((c >= 'a') && (c <= 'z')); };
+    auto extract_number = [&]() {
+        assert(idx < desc.size());
+        assert(is_num(desc[idx]));
+        size_t num = as_num(desc[idx++]);
+        assert(num != 0); // catch leading zeroes/zero size
+        while ((idx < desc.size()) && is_num(desc[idx])) {
+            num = (num * 10) + as_num(desc[idx++]);
+        }
+        return num;
+    };
+    assert(!desc.empty());
+    assert(is_dim_name(desc[idx]));
+    name.push_back(desc[idx++]);
+    size_t size = extract_number();
+    if (idx < desc.size()) {
+        // mapped
+        assert(is_map_tag(desc[idx++]));
+        size_t stride = 1;
+        if (idx < desc.size()) {
+            stride = extract_number();
+            assert(idx == desc.size());
+        }
+        return {name, make_dict(size, stride, "")};
+    } else {
+        // indexed
+        return {name, size};
+    }
+}
+
+// 'a2b12c5' -> GenSpec().idx("a", 2).idx("b", 12).idx("c", 5);
+// 'a2#b3#2c5#' -> GenSpec().map("a", 2).map("b", 3, 2).map("c", 5);
+GenSpec
+GenSpec::from_desc(const vespalib::string &desc)
+{
+    size_t idx = 0;
+    vespalib::string dim_desc;
+    std::vector<DimSpec> dim_list;
+    auto is_dim_name = [](char c) { return ((c >= 'a') && (c <= 'z')); };
+    while (idx < desc.size()) {
+        dim_desc.clear();
+        assert(is_dim_name(desc[idx]));
+        dim_desc.push_back(desc[idx++]);
+        while ((idx < desc.size()) && !is_dim_name(desc[idx])) {
+            dim_desc.push_back(desc[idx++]);
+        }
+        dim_list.push_back(DimSpec::from_desc(dim_desc));
+    }
+    return {std::move(dim_list)};
+}
+
 GenSpec::GenSpec(GenSpec &&other) = default;
 GenSpec::GenSpec(const GenSpec &other) = default;
 GenSpec &GenSpec::operator=(GenSpec &&other) = default;
diff --git a/eval/src/vespa/eval/eval/test/gen_spec.h b/eval/src/vespa/eval/eval/test/gen_spec.h
index bbc1663a11f..6943ba6c98a 100644
--- a/eval/src/vespa/eval/eval/test/gen_spec.h
+++ b/eval/src/vespa/eval/eval/test/gen_spec.h
@@ -76,6 +76,14 @@ public:
         assert(idx < size());
         return _size ? TensorSpec::Label{idx} : TensorSpec::Label{_dict[idx]};
     }
+
+    // Make a DimSpec object from a textual description
+    // (first character is used as dimension name)
+    //
+    // 'a2' -> DimSpec("a", 2);
+    // 'b2#' -> DimSpec("b", make_dict(2, 1, ""));
+    // 'c2#3' -> DimSpec("c", make_dict(2, 3, ""));
+    static DimSpec from_desc(const vespalib::string &desc);
 };
 
 /**
@@ -95,7 +103,14 @@ private:
 public:
     GenSpec() : _dims(), _cells(CellType::DOUBLE), _seq(N()) {}
     GenSpec(double bias) : _dims(), _cells(CellType::DOUBLE), _seq(N(bias)) {}
-    GenSpec(const std::vector<DimSpec> &dims_in) : _dims(dims_in), _cells(CellType::DOUBLE), _seq(N()) {}
+    GenSpec(std::vector<DimSpec> dims_in) : _dims(std::move(dims_in)), _cells(CellType::DOUBLE), _seq(N()) {}
+
+    // Make a GenSpec object from a textual description
+    // (dimension names must be single characters a-z)
+    //
+    // 'a2b12c5' -> GenSpec().idx("a", 2).idx("b", 12).idx("c", 5);
+    // 'a2#b3#2c5#' -> GenSpec().map("a", 2).map("b", 3, 2).map("c", 5);
+    static GenSpec from_desc(const vespalib::string &desc);
 
     GenSpec(GenSpec &&other);
     GenSpec(const GenSpec &other);
@@ -118,6 +133,10 @@ public:
         _dims.emplace_back(name, std::move(dict));
         return *this;
     }
+    GenSpec &desc(const vespalib::string &dim_desc) {
+        _dims.push_back(DimSpec::from_desc(dim_desc));
+        return *this;
+    }
     GenSpec &cells(CellType cell_type) {
         _cells = cell_type;
         return *this;