internal/rosa/azalea: evaluator

Performance is sufficient for the use case, despite the fact that I could not even think of a lower-effort way to do this:

BenchmarkParse-128        	   55100	     21494 ns/op
BenchmarkEvaluate-128     	  131670	      9248 ns/op

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 358 insertions, 0 deletions

diff --git a/internal/rosa/azalea/evaluate_test.go b/internal/rosa/azalea/evaluate_test.go
new file mode 100644
index 00000000..9036e782
--- /dev/null
+++ b/internal/rosa/azalea/evaluate_test.go
@@ -0,0 +1,358 @@
+package azalea_test
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+	"testing"
+	"unique"
+
+	. "hakurei.app/internal/rosa/azalea"
+)
+
+// makeStackCheck creates a stack with a single frame with a single function "f"
+// which calls the check function internally.
+func makeStackCheck(check func(args FArgs) (any, error)) []Frame {
+	return []Frame{{Func: map[unique.Handle[Ident]]F{
+		unique.Make(Ident("f")): {F: func(
+			isPackage bool,
+			args FArgs,
+		) (v any, set bool, err error) {
+			set = true
+			v, err = check(args)
+			if isPackage {
+				err = errors.New("unexpected package")
+			}
+			return
+		}},
+	}}}
+}
+
+func TestEvaluate(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		data string
+		s    []Frame
+		want string
+		err  error
+	}{
+		{"apply unset", `f { v = unset; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			v = "\xfd"
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &v,
+			})
+			return
+		}), "\xfd", nil},
+
+		{"apply bad type", `f { v = 9; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			v = "\xfd"
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &v,
+			})
+			return
+		}), "", TypeError{
+			Concrete: reflect.TypeFor[int64](),
+			Asserted: reflect.TypeFor[string](),
+		}},
+
+		{"apply undefined", `f { v = 9; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			v = "\xfd"
+			err = args.Apply(map[unique.Handle[Ident]]any{})
+			return
+		}), "", EvaluationError{
+			Expr: Func{
+				Ident: Ident("f"),
+				Args: []Arg{
+					{K: []Ident{"v"}, V: Val{Int(9)}},
+				},
+			},
+			Err: UndefinedError("v"),
+		}},
+
+		{"apply bound undefined", `f { _v* = "\x00"; v = _v; }`, makeStackCheck(func(
+			args FArgs,
+		) (v any, err error) {
+			v = "\xfd"
+			err = args.Apply(map[unique.Handle[Ident]]any{
+				unique.Make(Ident("v")): &v,
+			})
+			return
+		}), "\x00", nil},
+
+		{"undefined function", `f {}`, nil, "", EvaluationError{
+			Expr: Func{Ident: "f"},
+			Err:  UndefinedError("f"),
+		}},
+
+		{"error wrap deep", `f { v = nil; }`, makeStackCheck(func(
+			FArgs,
+		) (any, error) {
+			panic("unreachable")
+		}), "", EvaluationError{
+			Expr: Ident("nil"),
+			Err:  UndefinedError("nil"),
+		}},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			var expr Func
+			if e, err := Parse(strings.NewReader(tc.data)); err != nil {
+				t.Fatal(err)
+			} else if len(e) != 1 {
+				t.Fatalf("got expression %#v", e)
+			} else {
+				expr = e[0].(Func)
+			}
+			r, set, err := Evaluate[string](tc.s, expr)
+			if set != (err == nil) {
+				t.Error("Evaluate: unexpected unset")
+			}
+
+			if r != tc.want {
+				t.Errorf("Evaluate: %q, want %q", r, tc.want)
+			}
+
+			var errEquals bool
+			if errors.As(err, new(TypeError)) {
+				errEquals = errors.Is(err, tc.err)
+			} else {
+				errEquals = reflect.DeepEqual(err, tc.err)
+			}
+			if !errEquals {
+				t.Errorf("Evaluate: error = %v, want %v", err, tc.err)
+			}
+		})
+	}
+}
+
+func TestEvaluateGCC(t *testing.T) {
+	t.Parallel()
+
+	var gcc Func
+	if e, err := Parse(strings.NewReader(sample)); err != nil {
+		t.Fatal(err)
+	} else {
+		gcc = e[0].(Func)
+	}
+
+	var got [3]FArgs
+	if r, set, err := Evaluate[string]([]Frame{{
+		Func: map[unique.Handle[Ident]]F{
+			unique.Make(Ident("gcc")): {F: func(
+				isPackage bool,
+				args FArgs,
+			) (v any, set bool, err error) {
+				v = "\x00"
+				if !isPackage {
+					err = errors.New("not a package")
+				}
+				set = true
+				got[0] = args
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("binutils")):       "binutils",
+				unique.Make(Ident("mpc")):            "mpc",
+				unique.Make(Ident("zlib")):           "zlib",
+				unique.Make(Ident("libucontext")):    "libucontext",
+				unique.Make(Ident("kernel-headers")): "kernel-headers",
+			}},
+
+			unique.Make(Ident("remoteTar")): {F: func(
+				isPackage bool,
+				args FArgs,
+			) (v any, set bool, err error) {
+				if isPackage {
+					err = errors.New("unexpected package")
+					return
+				}
+
+				var url, checksum string
+				var compress int
+				if err = args.Apply(map[unique.Handle[Ident]]any{
+					unique.Make(Ident("url")):      &url,
+					unique.Make(Ident("checksum")): &checksum,
+					unique.Make(Ident("compress")): &compress,
+				}); err != nil {
+					return
+				}
+
+				if compress != 0xcafe {
+					err = fmt.Errorf("unexpected compress %#v", compress)
+				}
+				set = true
+				v = url + "?checksum=" + checksum
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("gzip")): 0xcafe,
+			}},
+
+			unique.Make(Ident("make")): {F: func(
+				isPackage bool,
+				args FArgs,
+			) (v any, set bool, err error) {
+				v = args
+				if isPackage {
+					err = errors.New("unexpected package")
+				}
+				set = true
+				return
+			}},
+
+			unique.Make(Ident("arch")): {F: func(
+				isPackage bool,
+				args FArgs,
+			) (v any, set bool, err error) {
+				set = false
+				if isPackage {
+					err = errors.New("unexpected package")
+				}
+				got[1] = args
+				return
+			}},
+
+			unique.Make(Ident("noop")): {F: func(
+				isPackage bool,
+				args FArgs,
+			) (v any, set bool, err error) {
+				set = false
+				if isPackage {
+					err = errors.New("unexpected package")
+				}
+				set = true
+				got[2] = args
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("value")): "\xfd",
+			}},
+		},
+	}}, gcc); err != nil {
+		t.Fatal(err)
+	} else if r != "\x00" {
+		t.Fatalf("package: %q", r)
+	} else if !set {
+		t.Fatal("package: unset")
+	}
+
+	want := [...]FArgs{
+		{
+			{K: unique.Make(Ident("description")), V: "The GNU Compiler Collection"},
+			{K: unique.Make(Ident("website")), V: "https://www.gnu.org/software/gcc"},
+			{K: unique.Make(Ident("anitya")), V: int64(6502)},
+
+			{K: unique.Make(Ident("version")), V: "16.1.0", R: true},
+			{K: unique.Make(Ident("source")), V: "https://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-16.1.0/gcc-16.1.0.tar.gz?checksum=4ASoWbxaA2FW7PAB0zzHDPC5XnNhyaAyjtDPpGzceSLeYnEIXsNYZR3PA_Zu5P0K"},
+			{K: unique.Make(Ident("patches")), V: []string{"musl-off64_t-loff_t.patch", "musl-legacy-lfs.patch"}},
+
+			{K: unique.Make(Ident("exclusive")), V: true},
+			{K: unique.Make(Ident("exec")), V: FArgs{
+				{K: unique.Make(Ident("configure")), V: [][2]string{
+					{"disable-multilib", ""},
+					{"enable-default-pie", ""},
+					{"disable-nls", ""},
+					{"with-gnu-as", ""},
+					{"with-gnu-ld", ""},
+					{"with-system-zlib", ""},
+					{"enable-languages", "c,c++,go"},
+					{"with-native-system-header-dir", "/system/include"},
+				}},
+				{K: unique.Make(Ident("make")), V: []string{
+					"BOOT_CFLAGS='-O2 -g'",
+					"\x00",
+					"bootstrap",
+				}},
+				{K: unique.Make(Ident("skip-check")), V: true},
+			}},
+
+			{K: unique.Make(Ident("inputs")), V: []string{
+				"binutils",
+				"mpc",
+				"zlib",
+				"libucontext",
+				"kernel-headers",
+			}},
+		},
+		{
+			{K: unique.Make(Ident("amd64")), V: "''"},
+			{K: unique.Make(Ident("arm64")), V: "''"},
+			{K: unique.Make(Ident("default"))},
+		},
+		{{K: unique.Make(Ident("key")), V: "\xfd"}},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("package: args = %#v, want %#v", got, want)
+	}
+}
+
+func BenchmarkEvaluate(b *testing.B) {
+	var gcc Func
+	if e, err := Parse(strings.NewReader(sample)); err != nil {
+		b.Fatal(err)
+	} else {
+		gcc = e[0].(Func)
+	}
+
+	s := []Frame{{
+		Func: map[unique.Handle[Ident]]F{
+			unique.Make(Ident("gcc")): {F: func(
+				bool,
+				FArgs,
+			) (v any, set bool, err error) {
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("binutils")):       "binutils",
+				unique.Make(Ident("mpc")):            "mpc",
+				unique.Make(Ident("zlib")):           "zlib",
+				unique.Make(Ident("libucontext")):    "libucontext",
+				unique.Make(Ident("kernel-headers")): "kernel-headers",
+			}},
+
+			unique.Make(Ident("remoteTar")): {F: func(
+				bool,
+				FArgs,
+			) (v any, set bool, err error) {
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("gzip")): 0xcafe,
+			}},
+
+			unique.Make(Ident("make")): {F: func(
+				bool,
+				FArgs,
+			) (v any, set bool, err error) {
+				return
+			}},
+
+			unique.Make(Ident("arch")): {F: func(
+				bool,
+				FArgs,
+			) (v any, set bool, err error) {
+				return
+			}},
+
+			unique.Make(Ident("noop")): {F: func(
+				bool,
+				FArgs,
+			) (v any, set bool, err error) {
+				return
+			}, V: map[unique.Handle[Ident]]any{
+				unique.Make(Ident("value")): "\xfd",
+			}},
+		},
+	}}
+	for b.Loop() {
+		if _, _, err := Evaluate[string](s, gcc); err != nil {
+			b.Fatal(err)
+		}
+	}
+}