gg/v2/gg.bnf

@@ -5,19 +5,20 @@
 
 <name> ::= (<letter> | <mark>) (<letter> | <mark> | <digit>)*
 
-<tuple>                ::= "(" <tuple-tail>
-<tuple-tail>           ::= ")" | <tuple-open-edge>
-<tuple-open-edge>      ::= <value> <tuple-open-edge-tail>
-<tuple-open-edge-tail> ::= ")"
-                         | "," <tuple-tail>
-                         | "<" <tuple-open-edge>
+<value> ::= <name> | <number> | <tuple> | <graph>
 
-<graph>                      ::= "{" <graph-tail>
-<graph-tail>                 ::= "}" | <name> "=" <graph-open-edge>
-<graph-open-edge>            ::= <value> <graph-open-edge-value-tail>
-                               | <tuple> <graph-open-edge-tail>
-<graph-open-edge-tail>       ::= "}" | ";" <graph-tail>
-<graph-open-edge-value-tail>  ::= <graph-open-edge-tail> | "<" <graph-open-edge>
+<tuple>            ::= "(" <tuple-tail>
+<tuple-tail>       ::= ")" | <value> <tuple-post-value>
+<tuple-post-value> ::= ")"
+                     | "," <tuple-tail>
+                     | "<" <value> <tuple-post-value>
 
-<value> ::= <name> | <number> | <graph>
-<gg>              ::= <eof> | <value> <gg>
+<graph>                ::= "{" <graph-tail>
+<graph-tail>           ::= "}" | <name> "=" <graph-open-edge>
+<graph-open-edge>      ::= <value> <graph-open-edge-tail>
+<graph-open-edge-tail> ::= "}"
+                         | ";" <graph-tail>
+                         | "<" <graph-open-edge>
+
+<top-level-value> ::= <name> | <number> | <graph>
+<gg>              ::= <eof> | <top-level-value> <gg>

gg/v2/location.go

@@ -25,6 +25,10 @@ func (e LocatedError) Error() string {
 	return fmt.Sprintf("%d:%d: %v", e.Row, e.Col, e.Err)
 }
 
+type locatable interface {
+	locate() Location
+}
+
 type locatableRune struct {
 	Location
 	r rune
@@ -34,3 +38,12 @@ type locatableString struct {
 	Location
 	str string
 }
+
+type locatableSlice[T locatable] []T
+
+func (s locatableSlice[T]) locate() Location {
+	if len(s) == 0 {
+		panic("can't locate empty locatableSlice")
+	}
+	return s[0].locate()
+}

gg/v2/term.go

@@ -9,7 +9,6 @@ import (
 	"unicode"
 
 	"github.com/mediocregopher/ginger/graph"
-	"golang.org/x/exp/slices"
 )
 
 var (
@@ -28,7 +27,7 @@ func (str stringerStr) String() string {
 	return string(str)
 }
 
-type term[T any] struct {
+type term[T locatable] struct {
 	name     fmt.Stringer
 	decodeFn func(d *Decoder) (T, error)
 }
@@ -37,7 +36,7 @@ func (t term[T]) String() string {
 	return t.name.String()
 }
 
-func firstOf[T any](terms ...*term[T]) *term[T] {
+func firstOf[T locatable](terms ...*term[T]) *term[T] {
 	if len(terms) < 2 {
 		panic("firstOfTerms requires at least 2 terms")
 	}
@@ -68,11 +67,11 @@ func firstOf[T any](terms ...*term[T]) *term[T] {
 	}
 }
 
-func seq[Ta, Tb, Tc any](
+func seq[Ta, Tb, Tc locatable](
 	name fmt.Stringer,
 	termA *term[Ta],
 	termB *term[Tb],
-	fn func(Ta, Tb) Tc,
+	fn func(Ta, Tb) (Tc, error),
 ) *term[Tc] {
 	return &term[Tc]{
 		name: name,
@@ -91,25 +90,30 @@ func seq[Ta, Tb, Tc any](
 				return zero, err
 			}
 
-			return fn(va, vb), nil
+			vc, err := fn(va, vb)
+			if err != nil {
+				return zero, err
+			}
+
+			return vc, nil
 		},
 	}
 }
 
-func matchAndSkip[Ta, Tb any](
+func matchAndSkip[Ta, Tb locatable](
 	termA *term[Ta], termB *term[Tb],
 ) *term[Tb] {
-	return seq(termA, termA, termB, func(_ Ta, b Tb) Tb {
-		return b
+	return seq(termA, termA, termB, func(_ Ta, b Tb) (Tb, error) {
+		return b, nil
 	})
 }
 
-func oneOrMore[T any](t *term[T]) *term[[]T] {
-	return &term[[]T]{
+func oneOrMore[T locatable](t *term[T]) *term[locatableSlice[T]] {
+	return &term[locatableSlice[T]]{
 		name: stringerFn(func() string {
 			return fmt.Sprintf("one or more %v", t)
 		}),
-		decodeFn: func(d *Decoder) ([]T, error) {
+		decodeFn: func(d *Decoder) (locatableSlice[T], error) {
 			var vv []T
 			for {
 				v, err := t.decodeFn(d)
@@ -131,12 +135,12 @@ func oneOrMore[T any](t *term[T]) *term[[]T] {
 	}
 }
 
-func zeroOrMore[T any](t *term[T]) *term[[]T] {
-	return &term[[]T]{
+func zeroOrMore[T locatable](t *term[T]) *term[locatableSlice[T]] {
+	return &term[locatableSlice[T]]{
 		name: stringerFn(func() string {
 			return fmt.Sprintf("zero or more %v", t)
 		}),
-		decodeFn: func(d *Decoder) ([]T, error) {
+		decodeFn: func(d *Decoder) (locatableSlice[T], error) {
 			var vv []T
 			for {
 				v, err := t.decodeFn(d)
@@ -154,7 +158,7 @@ func zeroOrMore[T any](t *term[T]) *term[[]T] {
 	}
 }
 
-func mapTerm[Ta, Tb any](
+func mapTerm[Ta locatable, Tb locatable](
 	name fmt.Stringer, t *term[Ta], fn func(Ta) Tb,
 ) *term[Tb] {
 	return &term[Tb]{
@@ -200,7 +204,7 @@ func runeTerm(r rune) *term[locatableRune] {
 	)
 }
 
-func locatableRunesToString(rr []locatableRune) string {
+func locatableRunesToString(rr locatableSlice[locatableRune]) string {
 	str := make([]rune, len(rr))
 	for i := range rr {
 		str[i] = rr[i].r
@@ -209,11 +213,11 @@ func locatableRunesToString(rr []locatableRune) string {
 }
 
 func runesToStringTerm(
-	t *term[[]locatableRune],
+	t *term[locatableSlice[locatableRune]],
 ) *term[locatableString] {
 	return mapTerm(
-		t, t, func(rr []locatableRune) locatableString {
-			return locatableString{rr[0].locate(), locatableRunesToString(rr)}
+		t, t, func(rr locatableSlice[locatableRune]) locatableString {
+			return locatableString{rr.locate(), locatableRunesToString(rr)}
 		},
 	)
 }
@@ -230,8 +234,10 @@ var (
 		stringerStr("negative-number"),
 		runeTerm('-'),
 		positiveNumberTerm,
-		func(neg locatableRune, posNum locatableString) locatableString {
-			return locatableString{neg.locate(), string(neg.r) + posNum.str}
+		func(neg locatableRune, posNum locatableString) (locatableString, error) {
+			return locatableString{
+				neg.locate(), string(neg.r) + posNum.str,
+			}, nil
 		},
 	)
 
@@ -263,125 +269,50 @@ var (
 		stringerStr("name"),
 		letterTerm,
 		letterTailTerm,
-		func(head locatableRune, tail []locatableRune) Value {
+		func(head locatableRune, tail locatableSlice[locatableRune]) (Value, error) {
 			name := string(head.r) + locatableRunesToString(tail)
-			return Value{Name: &name, Location: head.locate()}
+			return Value{Name: &name, Location: head.locate()}, nil
 		},
 	)
 )
 
-func openEdgeIntoValue(val Value, oe *OpenEdge) *OpenEdge {
-	switch {
-	case oe == nil:
-		return graph.ValueOut(None, val)
-	case !oe.EdgeValue().Valid:
-		return oe.WithEdgeValue(Some(val))
-	default:
-		return graph.TupleOut(Some(val), oe)
-	}
-}
-
 var graphTerm = func() *term[Value] {
-	type tupleState struct {
-		ins []*OpenEdge
-		oe  *OpenEdge
-	}
-
 	type graphState struct {
-		g  *Graph
-		oe *OpenEdge
+		Location // location of last place graphState was updated
+		g        *Graph
+		oe       *OpenEdge
 	}
 
-	var (
-		rightParenthesis = runeTerm(')')
-		tupleEndTerm     = mapTerm(
-			rightParenthesis,
-			rightParenthesis,
-			func(lr locatableRune) tupleState {
-				// if ')', then map that to an empty state. This acts as a
-				// sentinel value to indicate "end of tuple".
-				return tupleState{}
-			},
-		)
-
-		rightCurlyBrace = runeTerm('}')
-		graphEndTerm    = mapTerm(
-			rightCurlyBrace,
-			rightCurlyBrace,
-			func(lr locatableRune) graphState {
-				// if '}', then map that to an empty state. This acts as a
-				// sentinel value to indicate "end of graph".
-				return graphState{}
-			},
-		)
-	)
-
 	var (
 		// pre-define these, and then fill in the pointers after, in order to
 		// deal with recursive dependencies between them.
-		valueTerm = new(term[Value])
+		graphTerm             = new(term[Value])
+		graphTailTerm         = new(term[graphState])
+		graphOpenEdgeTerm     = new(term[graphState])
+		graphOpenEdgeTailTerm = new(term[graphState])
+		valueTerm             = new(term[Value])
 
-		tupleTerm             = new(term[*OpenEdge])
-		tupleTailTerm         = new(term[tupleState])
-		tupleOpenEdgeTerm     = new(term[tupleState])
-		tupleOpenEdgeTailTerm = new(term[tupleState])
-
-		graphTerm                  = new(term[Value])
-		graphTailTerm              = new(term[graphState])
-		graphOpenEdgeTerm          = new(term[graphState])
-		graphOpenEdgeTailTerm      = new(term[graphState])
-		graphOpenEdgeValueTailTerm = new(term[graphState])
-	)
-
-	*tupleTerm = *seq(
-		stringerStr("tuple"),
-		runeTerm('('),
-		tupleTailTerm,
-		func(lr locatableRune, ts tupleState) *OpenEdge {
-			slices.Reverse(ts.ins)
-			return graph.TupleOut(None, ts.ins...)
-		},
-	)
-
-	*tupleTailTerm = *firstOf(
-		tupleEndTerm,
-		mapTerm(
-			tupleOpenEdgeTerm,
-			tupleOpenEdgeTerm,
-			func(ts tupleState) tupleState {
-				ts.ins = append(ts.ins, ts.oe)
-				ts.oe = nil
-				return ts
+		rightCurlyBrace = runeTerm('}')
+		graphEndTerm    = mapTerm(
+			rightCurlyBrace,
+			rightCurlyBrace, func(lr locatableRune) graphState {
+				// if '}', then map that to an empty state. This acts as a
+				// sentinel value to indicate "end of graph".
+				return graphState{Location: lr.locate()}
 			},
-		),
-	)
-
-	*tupleOpenEdgeTerm = *seq(
-		valueTerm,
-		valueTerm,
-		tupleOpenEdgeTailTerm,
-		func(val Value, ts tupleState) tupleState {
-			ts.oe = openEdgeIntoValue(val, ts.oe)
-			return ts
-		},
-	)
-
-	*tupleOpenEdgeTailTerm = *firstOf(
-		tupleEndTerm,
-		matchAndSkip(runeTerm(','), tupleTailTerm),
-		matchAndSkip(runeTerm('<'), tupleOpenEdgeTerm),
+		)
 	)
 
 	*graphTerm = *seq(
 		stringerStr("graph"),
 		runeTerm('{'),
 		graphTailTerm,
-		func(lr locatableRune, gs graphState) Value {
+		func(lr locatableRune, gs graphState) (Value, error) {
 			if gs.g == nil {
 				gs.g = new(Graph)
 			}
 
-			return Value{Graph: gs.g, Location: lr.locate()}
+			return Value{Graph: gs.g, Location: lr.locate()}, nil
 		},
 	)
 
@@ -390,48 +321,42 @@ var graphTerm = func() *term[Value] {
 		seq(
 			nameTerm,
 			nameTerm,
-			matchAndSkip(runeTerm('='), graphOpenEdgeTerm),
-			func(name Value, gs graphState) graphState {
+			matchAndSkip(runeTerm('='), graphOpenEdgeTailTerm),
+			func(name Value, gs graphState) (graphState, error) {
 				if gs.g == nil {
 					gs.g = new(Graph)
 				}
 
 				gs.g = gs.g.AddValueIn(name, gs.oe)
 				gs.oe = nil
-				return gs
+				gs.Location = name.locate()
+				return gs, nil
 			},
 		),
 	)
 
 	*graphOpenEdgeTerm = *firstOf(
-		seq(
-			valueTerm,
-			valueTerm,
-			graphOpenEdgeValueTailTerm,
-			func(val Value, gs graphState) graphState {
-				gs.oe = openEdgeIntoValue(val, gs.oe)
-				return gs
-			},
-		),
-		seq(
-			tupleTerm,
-			tupleTerm,
-			graphOpenEdgeTailTerm,
-			func(oe *OpenEdge, gs graphState) graphState {
-				gs.oe = oe
-				return gs
-			},
-		),
-	)
-
-	*graphOpenEdgeTailTerm = *firstOf(
 		graphEndTerm,
 		matchAndSkip(runeTerm(';'), graphTailTerm),
+		matchAndSkip(runeTerm('<'), graphOpenEdgeTailTerm),
 	)
 
-	*graphOpenEdgeValueTailTerm = *firstOf(
-		graphOpenEdgeTailTerm,
-		matchAndSkip(runeTerm('<'), graphOpenEdgeTerm),
+	*graphOpenEdgeTailTerm = *seq(
+		valueTerm,
+		valueTerm,
+		graphOpenEdgeTerm,
+		func(val Value, gs graphState) (graphState, error) {
+			if gs.oe == nil {
+				gs.oe = graph.ValueOut(None, val)
+			} else if !gs.oe.EdgeValue().Valid {
+				gs.oe = gs.oe.WithEdgeValue(Some(val))
+			} else {
+				gs.oe = graph.TupleOut(Some(val), gs.oe)
+			}
+
+			gs.Location = val.locate()
+			return gs, nil
+		},
 	)
 
 	*valueTerm = *firstOf(nameTerm, numberTerm, graphTerm)

gg/v2/term_test.go

@@ -84,7 +84,7 @@ func TestTermDecoding(t *testing.T) {
 		{in: `{}`, exp: expGraph(1, 1, new(Graph))},
 		{in: `{`, expErr: `1:2: expected '}' or name`},
 		{in: `{a}`, expErr: `1:3: expected '='`},
-		{in: `{a=}`, expErr: `1:4: expected name or number or graph or tuple`},
+		{in: `{a=}`, expErr: `1:4: expected name or number or graph`},
 		{
 			in: `{foo=a}`,
 			exp: expGraph(
@@ -217,89 +217,4 @@ func TestTermDecoding(t *testing.T) {
 			),
 		},
 	})
-
-	runTests(t, "tuple", graphTerm, []test{
-		{
-			in: `{foo=(a)}`,
-			exp: expGraph(
-				1, 1, new(Graph).
-					AddValueIn(
-						expName(2, 1, "foo"),
-						graph.ValueOut(None, expName(6, 1, "a")),
-					),
-			),
-		},
-		{
-			in: `{foo=(a<b)}`,
-			exp: expGraph(
-				1, 1, new(Graph).
-					AddValueIn(
-						expName(2, 1, "foo"),
-						graph.ValueOut(
-							Some(expName(6, 1, "a")),
-							expName(8, 1, "b"),
-						),
-					),
-			),
-		},
-		{
-			in: `{foo=a<(b)}`,
-			exp: expGraph(
-				1, 1, new(Graph).
-					AddValueIn(
-						expName(2, 1, "foo"),
-						graph.ValueOut(
-							Some(expName(6, 1, "a")),
-							expName(8, 1, "b"),
-						),
-					),
-			),
-		},
-		{
-			in: `{foo=a<(b,c)}`,
-			exp: expGraph(
-				1, 1, new(Graph).
-					AddValueIn(
-						expName(2, 1, "foo"),
-						graph.TupleOut(
-							Some(expName(6, 1, "a")),
-							graph.ValueOut(None, expName(8, 1, "b")),
-							graph.ValueOut(None, expName(10, 1, "c")),
-						),
-					),
-			),
-		},
-		{
-			in: `{foo=a<(b<c)}`,
-			exp: expGraph(
-				1, 1, new(Graph).
-					AddValueIn(
-						expName(2, 1, "foo"),
-						graph.TupleOut(
-							Some(expName(6, 1, "a")),
-							graph.TupleOut(
-								Some(expName(6, 1, "b")),
-								graph.ValueOut(None, expName(8, 1, "c")),
-							),
-						),
-					),
-			),
-		},
-		//{
-		//	in: `{foo=a<(b<(c))}`,
-		//	exp: expGraph(
-		//		1, 1, new(Graph).
-		//			AddValueIn(
-		//				expName(2, 1, "foo"),
-		//				graph.TupleOut(
-		//					Some(expName(6, 1, "a")),
-		//					graph.TupleOut(
-		//						Some(expName(6, 1, "b")),
-		//						graph.ValueOut(None, expName(8, 1, "c")),
-		//					),
-		//				),
-		//			),
-		//	),
-		//},
-	})
 }

go.mod

@@ -7,6 +7,5 @@ require github.com/stretchr/testify v1.7.0
 require (
 	github.com/davecgh/go-spew v1.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )

go.sum

@@ -5,8 +5,6 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
-golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

graph/graph.go

@@ -126,7 +126,7 @@ func TupleOut[E, V Value](edgeVal E, ins ...*OpenEdge[E, V]) *OpenEdge[E, V] {
 	if len(ins) == 1 {
 
 		var (
-			zero E
+			zero V
 			in   = ins[0]
 		)
 
@@ -353,6 +353,7 @@ type reducedEdge[Ea, Va Value, Vb any] struct {
 // If a value or edge is connected to multiple times within the root OpenEdge it
 // will only be mapped/reduced a single time, and the result of that single
 // map/reduction will be passed to each dependant operation.
+//
 func MapReduce[Ea, Va Value, Vb any](
 	root *OpenEdge[Ea, Va],
 	mapVal func(Va) (Vb, error),