Extract and DRY AssignNull method for most types.

This one turns out to be different betweens scalars and recursives,
if in a small (and fortunately consistent) way.

schema/gen/go/genCommon.go

@@ -109,14 +109,46 @@ func emitNodeAssemblerType_scalar(w io.Writer, adjCfg *AdjunctCfg, data interfac
 	`, w, adjCfg, data)
 }
 
+func emitNodeAssemblerMethodAssignNull_scalar(w io.Writer, adjCfg *AdjunctCfg, data interface{}) {
+	doTemplate(`
+		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
+			switch *na.m {
+			case allowNull:
+				*na.m = schema.Maybe_Null
+				return nil
+			case schema.Maybe_Absent:
+				return mixins.{{ .ReprKind.String | title }}Assembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
+			case schema.Maybe_Value, schema.Maybe_Null:
+				panic("invalid state: cannot assign into assembler that's already finished")
+			}
+			panic("unreachable")
+		}
+	`, w, adjCfg, data)
+}
+
+// almost the same as the variant for scalars, but also has to check for midvalue state.
+func emitNodeAssemblerMethodAssignNull_recursive(w io.Writer, adjCfg *AdjunctCfg, data interface{}) {
+	doTemplate(`
+		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
+			switch *na.m {
+			case allowNull:
+				*na.m = schema.Maybe_Null
+				return nil
+			case schema.Maybe_Absent:
+				return mixins.{{ .ReprKind.String | title }}Assembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
+			case schema.Maybe_Value, schema.Maybe_Null:
+				panic("invalid state: cannot assign into assembler that's already finished")
+			case midvalue:
+				panic("invalid state: cannot assign null into an assembler that's already begun working on recursive structures!")
+			}
+			panic("unreachable")
+		}
+	`, w, adjCfg, data)
+}
+
 /*
 	Some things that might make it easier to DRY stuff, if they were standard in the 'data' obj:
 
-		- KindUpper
-			- e.g. makes it possible to hoist out 'AssignNull', which needs to refer to a kind-particular mixin type.
-			- also usable for to make 'AssignNode' hoistable for scalars.
-				- works purely textually for scalars, conveniently.
-				- maps and lists would need to branch entirely for the bottom half of the method.
 		- IsRepr
 			- ...?  Somewhat unsure on this one; many different ways to cut this.
 			- Would be used as `{{if .IsRepr}}Repr{{end}}` in some cases, and `{{if .IsRepr}}__Repr{{end}}` in others...

schema/gen/go/genInt.go

@@ -150,20 +150,7 @@ func (g intBuilderGenerator) EmitNodeAssemblerType(w io.Writer) {
 	emitNodeAssemblerType_scalar(w, g.AdjCfg, g)
 }
 func (g intBuilderGenerator) EmitNodeAssemblerMethodAssignNull(w io.Writer) {
-	doTemplate(`
-		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
-			switch *na.m {
-			case allowNull:
-				*na.m = schema.Maybe_Null
-				return nil
-			case schema.Maybe_Absent:
-				return mixins.IntAssembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
-			case schema.Maybe_Value, schema.Maybe_Null:
-				panic("invalid state: cannot assign into assembler that's already finished")
-			}
-			panic("unreachable")
-		}
-	`, w, g.AdjCfg, g)
+	emitNodeAssemblerMethodAssignNull_scalar(w, g.AdjCfg, g)
 }
 func (g intBuilderGenerator) EmitNodeAssemblerMethodAssignInt(w io.Writer) {
 	// This method contains a branch to support MaybeUsesPtr because new memory may need to be allocated.

schema/gen/go/genList.go

@@ -254,23 +254,7 @@ func (g listBuilderGenerator) EmitNodeAssemblerMethodBeginList(w io.Writer) {
 	`, w, g.AdjCfg, g)
 }
 func (g listBuilderGenerator) EmitNodeAssemblerMethodAssignNull(w io.Writer) {
-	// DRY: this seems awfully similar -- almost exact, even -- *even* to anything mapoid (except the mixin type name contains 'List' instead of 'Map').
-	doTemplate(`
-		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
-			switch *na.m {
-			case allowNull:
-				*na.m = schema.Maybe_Null
-				return nil
-			case schema.Maybe_Absent:
-				return mixins.ListAssembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
-			case schema.Maybe_Value, schema.Maybe_Null:
-				panic("invalid state: cannot assign into assembler that's already finished")
-			case midvalue:
-				panic("invalid state: cannot assign null into an assembler that's already begun working on recursive structures!")
-			}
-			panic("unreachable")
-		}
-	`, w, g.AdjCfg, g)
+	emitNodeAssemblerMethodAssignNull_recursive(w, g.AdjCfg, g)
 }
 func (g listBuilderGenerator) EmitNodeAssemblerMethodAssignNode(w io.Writer) {
 	// AssignNode goes through three phases:

schema/gen/go/genMap.go

@@ -332,24 +332,7 @@ func (g mapBuilderGenerator) EmitNodeAssemblerMethodBeginMap(w io.Writer) {
 	`, w, g.AdjCfg, g)
 }
 func (g mapBuilderGenerator) EmitNodeAssemblerMethodAssignNull(w io.Writer) {
-	// DRY: this seems awfully similar -- almost exact, even -- amongst anything mapoid.  Can we extract?
-	//  Might even be something we can turn into a util function, not just a template dry.  Only parameters are '*m', kind mixin, and type name.
-	doTemplate(`
-		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
-			switch *na.m {
-			case allowNull:
-				*na.m = schema.Maybe_Null
-				return nil
-			case schema.Maybe_Absent:
-				return mixins.MapAssembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
-			case schema.Maybe_Value, schema.Maybe_Null:
-				panic("invalid state: cannot assign into assembler that's already finished")
-			case midvalue:
-				panic("invalid state: cannot assign null into an assembler that's already begun working on recursive structures!")
-			}
-			panic("unreachable")
-		}
-	`, w, g.AdjCfg, g)
+	emitNodeAssemblerMethodAssignNull_recursive(w, g.AdjCfg, g)
 }
 func (g mapBuilderGenerator) EmitNodeAssemblerMethodAssignNode(w io.Writer) {
 	// AssignNode goes through three phases:

schema/gen/go/genString.go

@@ -160,20 +160,7 @@ func (g stringBuilderGenerator) EmitNodeAssemblerType(w io.Writer) {
 	emitNodeAssemblerType_scalar(w, g.AdjCfg, g)
 }
 func (g stringBuilderGenerator) EmitNodeAssemblerMethodAssignNull(w io.Writer) {
-	doTemplate(`
-		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
-			switch *na.m {
-			case allowNull:
-				*na.m = schema.Maybe_Null
-				return nil
-			case schema.Maybe_Absent:
-				return mixins.StringAssembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
-			case schema.Maybe_Value, schema.Maybe_Null:
-				panic("invalid state: cannot assign into assembler that's already finished")
-			}
-			panic("unreachable")
-		}
-	`, w, g.AdjCfg, g)
+	emitNodeAssemblerMethodAssignNull_scalar(w, g.AdjCfg, g)
 }
 func (g stringBuilderGenerator) EmitNodeAssemblerMethodAssignString(w io.Writer) {
 	// This method contains a branch to support MaybeUsesPtr because new memory may need to be allocated.

schema/gen/go/genStruct.go

@@ -309,22 +309,7 @@ func (g structBuilderGenerator) EmitNodeAssemblerMethodBeginMap(w io.Writer) {
 	`, w, g.AdjCfg, g)
 }
 func (g structBuilderGenerator) EmitNodeAssemblerMethodAssignNull(w io.Writer) {
-	doTemplate(`
-		func (na *_{{ .Type | TypeSymbol }}__Assembler) AssignNull() error {
-			switch *na.m {
-			case allowNull:
-				*na.m = schema.Maybe_Null
-				return nil
-			case schema.Maybe_Absent:
-				return mixins.MapAssembler{"{{ .PkgName }}.{{ .TypeName }}"}.AssignNull()
-			case schema.Maybe_Value, schema.Maybe_Null:
-				panic("invalid state: cannot assign into assembler that's already finished")
-			case midvalue:
-				panic("invalid state: cannot assign null into an assembler that's already begun working on recursive structures!")
-			}
-			panic("unreachable")
-		}
-	`, w, g.AdjCfg, g)
+	emitNodeAssemblerMethodAssignNull_recursive(w, g.AdjCfg, g)
 }
 func (g structBuilderGenerator) EmitNodeAssemblerMethodAssignNode(w io.Writer) {
 	// AssignNode goes through three phases:

schema/gen/go/mixins/intGenMixin.go

@@ -68,6 +68,9 @@ type IntAssemblerTraits struct {
 	AppliedPrefix string // see doc in kindAssemblerTraitsGenerator
 }
 
+func (IntAssemblerTraits) ReprKind() ipld.ReprKind {
+	return ipld.ReprKind_Int
+}
 func (g IntAssemblerTraits) EmitNodeAssemblerMethodBeginMap(w io.Writer) {
 	kindAssemblerTraitsGenerator{g.PkgName, g.TypeName, g.AppliedPrefix, ipld.ReprKind_Int}.emitNodeAssemblerMethodBeginMap(w)
 }

schema/gen/go/mixins/listGenMixin.go

@@ -67,6 +67,9 @@ type ListAssemblerTraits struct {
 	AppliedPrefix string // see doc in kindAssemblerTraitsGenerator
 }
 
+func (ListAssemblerTraits) ReprKind() ipld.ReprKind {
+	return ipld.ReprKind_List
+}
 func (g ListAssemblerTraits) EmitNodeAssemblerMethodBeginMap(w io.Writer) {
 	kindAssemblerTraitsGenerator{g.PkgName, g.TypeName, g.AppliedPrefix, ipld.ReprKind_List}.emitNodeAssemblerMethodBeginMap(w)
 }

schema/gen/go/mixins/mapGenMixin.go

@@ -63,6 +63,9 @@ type MapAssemblerTraits struct {
 	AppliedPrefix string // see doc in kindAssemblerTraitsGenerator
 }
 
+func (MapAssemblerTraits) ReprKind() ipld.ReprKind {
+	return ipld.ReprKind_Map
+}
 func (g MapAssemblerTraits) EmitNodeAssemblerMethodBeginList(w io.Writer) {
 	kindAssemblerTraitsGenerator{g.PkgName, g.TypeName, g.AppliedPrefix, ipld.ReprKind_Map}.emitNodeAssemblerMethodBeginList(w)
 }

schema/gen/go/mixins/stringGenMixin.go

@@ -68,6 +68,9 @@ type StringAssemblerTraits struct {
 	AppliedPrefix string // see doc in kindAssemblerTraitsGenerator
 }
 
+func (StringAssemblerTraits) ReprKind() ipld.ReprKind {
+	return ipld.ReprKind_String
+}
 func (g StringAssemblerTraits) EmitNodeAssemblerMethodBeginMap(w io.Writer) {
 	kindAssemblerTraitsGenerator{g.PkgName, g.TypeName, g.AppliedPrefix, ipld.ReprKind_String}.emitNodeAssemblerMethodBeginMap(w)
 }

schema/gen/go/templateUtil.go

@@ -2,6 +2,7 @@ package gengo
 
 import (
 	"io"
+	"strings"
 	"text/template"
 
 	wish "github.com/warpfork/go-wish"
@@ -15,6 +16,7 @@ func doTemplate(tmplstr string, w io.Writer, adjCfg *AdjunctCfg, data interface{
 			"FieldSymbolUpper": adjCfg.FieldSymbolUpper,
 			"MaybeUsesPtr":     adjCfg.MaybeUsesPtr,
 			"add":              func(a, b int) int { return a + b },
+			"title":            func(s string) string { return strings.Title(s) },
 		}).
 		// Seriously consider prepending `{{ $dot := . }}` (or 'top', or something).
 		// Or a func into the map that causes `dot` to mean `func() interface{} { return data }`.