lang: ast, funcs: Start plumbing through the textarea

We need to get these everywhere and this is a start.

lang/ast/structs.go

@@ -3960,6 +3960,8 @@ func (obj *StmtFor) Graph(env *interfaces.Env) (*pgraph.Graph, error) {
 		extendedEnv.Variables[obj.indexParam.envKey] = &interfaces.FuncSingleton{
 			MakeFunc: func() (*pgraph.Graph, interfaces.Func, error) {
 				f := &structs.ConstFunc{
+					Textarea: obj.Textarea, // XXX: advance by `for ` chars?
+
 					Value: &types.IntValue{
 						V: int64(index),
 					},
@@ -4022,6 +4024,8 @@ func (obj *StmtFor) Graph(env *interfaces.Env) (*pgraph.Graph, error) {
 	// Add a vertex for the list passing itself.
 	edgeName := structs.ForFuncArgNameList
 	forFunc := &structs.ForFunc{
+		Textarea: obj.Textarea,
+
 		IndexType: obj.indexParam.typ,
 		ValueType: obj.valueParam.typ,
 
@@ -4522,6 +4526,8 @@ func (obj *StmtForKV) Graph(env *interfaces.Env) (*pgraph.Graph, error) {
 	// Add a vertex for the map passing itself.
 	edgeName := structs.ForKVFuncArgNameMap
 	forKVFunc := &structs.ForKVFunc{
+		Textarea: obj.Textarea,
+
 		KeyType: obj.keyParam.typ,
 		ValType: obj.valParam.typ,
 
@@ -7415,6 +7421,8 @@ func (obj *ExprBool) Check(typ *types.Type) ([]*interfaces.UnificationInvariant,
 // Func returns the reactive stream of values that this expression produces.
 func (obj *ExprBool) Func() (interfaces.Func, error) {
 	return &structs.ConstFunc{
+		Textarea: obj.Textarea,
+
 		Value: &types.BoolValue{V: obj.V},
 	}, nil
 }
@@ -7612,6 +7620,8 @@ func (obj *ExprStr) Check(typ *types.Type) ([]*interfaces.UnificationInvariant,
 // Func returns the reactive stream of values that this expression produces.
 func (obj *ExprStr) Func() (interfaces.Func, error) {
 	return &structs.ConstFunc{
+		Textarea: obj.Textarea,
+
 		Value: &types.StrValue{V: obj.V},
 	}, nil
 }
@@ -7765,6 +7775,8 @@ func (obj *ExprInt) Check(typ *types.Type) ([]*interfaces.UnificationInvariant,
 // Func returns the reactive stream of values that this expression produces.
 func (obj *ExprInt) Func() (interfaces.Func, error) {
 	return &structs.ConstFunc{
+		Textarea: obj.Textarea,
+
 		Value: &types.IntValue{V: obj.V},
 	}, nil
 }
@@ -7920,6 +7932,8 @@ func (obj *ExprFloat) Check(typ *types.Type) ([]*interfaces.UnificationInvariant
 // Func returns the reactive stream of values that this expression produces.
 func (obj *ExprFloat) Func() (interfaces.Func, error) {
 	return &structs.ConstFunc{
+		Textarea: obj.Textarea,
+
 		Value: &types.FloatValue{V: obj.V},
 	}, nil
 }
@@ -8231,6 +8245,8 @@ func (obj *ExprList) Func() (interfaces.Func, error) {
 
 	// composite func (list, map, struct)
 	return &structs.CompositeFunc{
+		Textarea: obj.Textarea,
+
 		Type: typ,
 		Len:  len(obj.Elements),
 	}, nil
@@ -8683,6 +8699,8 @@ func (obj *ExprMap) Func() (interfaces.Func, error) {
 
 	// composite func (list, map, struct)
 	return &structs.CompositeFunc{
+		Textarea: obj.Textarea,
+
 		Type: typ, // the key/val types are known via this type
 		Len:  len(obj.KVs),
 	}, nil
@@ -9120,6 +9138,8 @@ func (obj *ExprStruct) Func() (interfaces.Func, error) {
 
 	// composite func (list, map, struct)
 	return &structs.CompositeFunc{
+		Textarea: obj.Textarea,
+
 		Type: typ,
 	}, nil
 }
@@ -10980,6 +11000,8 @@ func (obj *ExprCall) Graph(env *interfaces.Env) (*pgraph.Graph, interfaces.Func,
 	// Add a vertex for the call itself.
 	edgeName := structs.CallFuncArgNameFunction
 	callFunc := &structs.CallFunc{
+		Textarea: obj.Textarea,
+
 		Type:        obj.typ,
 		FuncType:    ftyp,
 		EdgeName:    edgeName,
@@ -12686,6 +12708,8 @@ func (obj *ExprIf) Func() (interfaces.Func, error) {
 	}
 
 	return &structs.IfFunc{
+		Textarea: obj.Textarea,
+
 		Type: typ, // this is the output type of the expression
 	}, nil
 }

lang/funcs/structs/call.go

@@ -53,6 +53,8 @@ const (
 // The arguments are connected to the received FuncValues in such a way that
 // CallFunc emits the result of applying the function to the arguments.
 type CallFunc struct {
+	interfaces.Textarea
+
 	Type     *types.Type // the type of the result of applying the function
 	FuncType *types.Type // the type of the function
 	EdgeName string      // name of the edge used

lang/funcs/structs/composite.go

@@ -48,6 +48,8 @@ const (
 // value as a stream that depends on those inputs. It helps the list, map, and
 // struct's that fulfill the Expr interface but expressing a Func method.
 type CompositeFunc struct {
+	interfaces.Textarea
+
 	Type *types.Type // this is the type of the composite value we hold
 	Len  int         // length of list or map (if used)
 

lang/funcs/structs/const.go

@@ -44,6 +44,8 @@ const (
 
 // ConstFunc is a function that returns the constant value passed to Value.
 type ConstFunc struct {
+	interfaces.Textarea
+
 	Value    types.Value
 	NameHint string
 

lang/funcs/structs/for.go

@@ -51,6 +51,8 @@ const (
 // build a subgraph that processes each element, and in doing so we get a larger
 // function graph. This is rebuilt as necessary if the input list changes.
 type ForFunc struct {
+	interfaces.Textarea
+
 	IndexType *types.Type
 	ValueType *types.Type
 

lang/funcs/structs/forkv.go

@@ -51,6 +51,8 @@ const (
 // build a subgraph that processes each key and val, and in doing so we get a
 // larger function graph. This is rebuilt as necessary if the input map changes.
 type ForKVFunc struct {
+	interfaces.Textarea
+
 	KeyType *types.Type
 	ValType *types.Type
 

lang/funcs/structs/if.go

@@ -45,6 +45,8 @@ const (
 // IfFunc is a function that passes through the value of the correct branch
 // based on the conditional value it gets.
 type IfFunc struct {
+	interfaces.Textarea
+
 	Type *types.Type // this is the type of the if expression output we hold
 
 	init   *interfaces.Init

lang/funcs/structs/util.go

@@ -45,6 +45,8 @@ import (
 // which is implemented by &ConstFunc{}.
 func FuncValueToConstFunc(fv *full.FuncValue) interfaces.Func {
 	return &ConstFunc{
+		//Textarea: ???, // XXX: add me!
+
 		Value:    fv,
 		NameHint: "FuncValue",
 	}