line numbers in the AST re #732

cli/run.go

@@ -152,7 +152,7 @@ func (obj *RunArgs) Run(ctx context.Context, data *cliUtil.Data) (bool, error) {
 
 	deploy, err := gapiObj.Cli(info)
 	if err != nil {
-		return false, cliUtil.CliParseError(err) // consistent errors
+		return false, cliUtil.CliParseError(err) // TODO: it seems unlikely that parsing the CLI failed at this stage, and then the error will be misleading
 	}
 
 	if cmd := obj.RunLang; cmd != nil && cmd.OnlyUnify && deploy == nil {

lang/ast/structs.go

@@ -177,17 +177,56 @@ var (
 	orderingGraphSingleton = false
 )
 
+// TextArea stores the coordinates of a statement or expression in the form of
+// starting line/column and ending line/column
+type TextArea struct {
+	startLine int
+	startColumn int
+	endLine int
+	endColumn int
+
+	// Bug5819 works around issue https://github.com/golang/go/issues/5819
+	Bug5819 interface{} // XXX: workaround
+}
+
+// Locate is used by the parser to store the token positions in AST nodes
+func (a *TextArea) Locate(line int, col int, endline int, endcol int) {
+	a.startLine = line
+	a.startColumn = col
+	a.endLine = endline
+	a.endColumn = endcol
+}
+
+// LocalNode is the interface implemented by AST nodes that store their code
+// position. It is implemented by node types that embed TextArea.
+type LocalNode interface {
+	Locate(int, int, int, int)
+	GetPosition() (int, int)
+	GetEndPosition() (int, int)
+}
+
+// GetPosition returns the starting line/column of an AST node
+func (a TextArea) GetPosition() (int, int) {
+	return a.startLine, a.startColumn
+}
+
+// GetEndPosition returns the end line/column of an AST node
+func (a TextArea) GetEndPosition() (int, int) {
+	return a.endLine, a.endColumn
+}
+
 // StmtBind is a representation of an assignment, which binds a variable to an
 // expression.
 type StmtBind struct {
 	Ident string
 	Value interfaces.Expr
 	Type  *types.Type
+	TextArea
 }
 
 // String returns a short representation of this statement.
 func (obj *StmtBind) String() string {
-	return fmt.Sprintf("bind(%s)", obj.Ident)
+	return fmt.Sprintf("bind(%s) @ (%d %d)", obj.Ident, obj.startLine+1, obj.startColumn+1)
 }
 
 // Apply is a general purpose iterator method that operates on any AST node. It
@@ -220,11 +259,9 @@ func (obj *StmtBind) Interpolate() (interfaces.Stmt, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &StmtBind{
-		Ident: obj.Ident,
-		Value: interpolated,
-		Type:  obj.Type,
-	}, nil
+	result := *obj
+	result.Value = interpolated
+	return &result, nil
 }
 
 // Copy returns a light copy of this struct. Anything static will not be copied.
@@ -365,6 +402,7 @@ type StmtRes struct {
 	Name     interfaces.Expr   // unique name for the res of this kind
 	namePtr  interfaces.Func   // ptr for table lookup
 	Contents []StmtResContents // list of fields/edges in parsed order
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -2059,6 +2097,7 @@ type StmtEdge struct {
 
 	// TODO: should notify be an Expr?
 	Notify bool // specifies that this edge sends a notification as well
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -2561,6 +2600,7 @@ type StmtIf struct {
 	conditionPtr interfaces.Func // ptr for table lookup
 	ThenBranch   interfaces.Stmt // optional, but usually present
 	ElseBranch   interfaces.Stmt // optional
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -2576,6 +2616,8 @@ func (obj *StmtIf) String() string {
 		s += fmt.Sprintf(" else { %s }", obj.ElseBranch.String())
 	}
 
+	s += fmt.Sprintf(" @ (%d %d)", obj.startLine+1, obj.startColumn+1)
+
 	return s
 }
 
@@ -2642,11 +2684,11 @@ func (obj *StmtIf) Interpolate() (interfaces.Stmt, error) {
 			return nil, errwrap.Wrapf(err, "could not interpolate ElseBranch")
 		}
 	}
-	return &StmtIf{
-		Condition:  condition,
-		ThenBranch: thenBranch,
-		ElseBranch: elseBranch,
-	}, nil
+	result := *obj
+	result.Condition = condition
+	result.ThenBranch = thenBranch
+	result.ElseBranch = elseBranch
+	return &result, nil
 }
 
 // Copy returns a light copy of this struct. Anything static will not be copied.
@@ -2923,6 +2965,7 @@ type StmtProg struct {
 	importFiles []string    // list of files seen during the SetScope import
 
 	Body []interfaces.Stmt
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -4312,6 +4355,7 @@ type StmtFunc struct {
 	Name string
 	Func interfaces.Expr
 	Type *types.Type
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -4518,6 +4562,7 @@ type StmtClass struct {
 	Name string
 	Args []*interfaces.Arg
 	Body interfaces.Stmt // probably a *StmtProg
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -4720,6 +4765,7 @@ type StmtInclude struct {
 	Name  string
 	Args  []interfaces.Expr
 	Alias string
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -5085,6 +5131,7 @@ func (obj *StmtInclude) Output(table map[interfaces.Func]types.Value) (*interfac
 type StmtImport struct {
 	Name  string
 	Alias string
+	TextArea
 }
 
 // String returns a short representation of this statement.
@@ -5266,6 +5313,7 @@ type ExprBool struct {
 	scope *interfaces.Scope // store for referencing this later
 
 	V bool
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -5411,6 +5459,7 @@ type ExprStr struct {
 	scope *interfaces.Scope // store for referencing this later
 
 	V string // value of this string
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -5606,6 +5655,7 @@ type ExprInt struct {
 	scope *interfaces.Scope // store for referencing this later
 
 	V int64
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -5749,6 +5799,7 @@ type ExprFloat struct {
 	scope *interfaces.Scope // store for referencing this later
 
 	V float64
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -5896,6 +5947,7 @@ type ExprList struct {
 
 	//Elements []*ExprListElement
 	Elements []interfaces.Expr
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -6249,6 +6301,7 @@ type ExprMap struct {
 	typ   *types.Type
 
 	KVs []*ExprMapKV
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -6734,6 +6787,7 @@ type ExprStruct struct {
 	typ   *types.Type
 
 	Fields []*ExprStructField // the list (fields) are intentionally ordered!
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -7166,6 +7220,7 @@ type ExprFunc struct {
 
 	// XXX: is this necessary?
 	//V func(interfaces.Txn, []pgraph.Vertex) (pgraph.Vertex, error)
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -7910,6 +7965,7 @@ type ExprCall struct {
 	Args []interfaces.Expr // list of args in parsed order
 	// Var specifies whether the function being called is a lambda in a var.
 	Var bool
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -7918,7 +7974,9 @@ func (obj *ExprCall) String() string {
 	for _, x := range obj.Args {
 		s = append(s, fmt.Sprintf("%s", x.String()))
 	}
-	return fmt.Sprintf("call:%s(%s)", obj.Name, strings.Join(s, ", "))
+	result := fmt.Sprintf("call:%s(%s)", obj.Name, strings.Join(s, ", "))
+	result += fmt.Sprintf(" @ (%d %d)", obj.startLine+1, obj.startColumn+1)
+	return result
 }
 
 // Apply is a general purpose iterator method that operates on any AST node. It
@@ -7965,19 +8023,11 @@ func (obj *ExprCall) Interpolate() (interfaces.Expr, error) {
 		orig = obj.orig
 	}
 
-	return &ExprCall{
-		data:  obj.data,
-		scope: obj.scope,
-		typ:   obj.typ,
-		// XXX: Copy copies this, do we want to here as well? (or maybe
-		// we want to do it here, but not in Copy?)
-		expr: obj.expr,
-		orig: orig,
-		V:    obj.V,
-		Name: obj.Name,
-		Args: args,
-		Var:  obj.Var,
-	}, nil
+	result := *obj
+	result.orig = orig
+	result.Args = args
+
+	return &result, nil
 }
 
 // Copy returns a light copy of this struct. Anything static will not be copied.
@@ -8365,7 +8415,7 @@ func (obj *ExprCall) Infer() (*types.Type, []*interfaces.UnificationInvariant, e
 	var typExpr *types.Type // out
 
 	// Look at what kind of function we are calling...
-	callee := trueCallee(obj.expr)
+	callee := TrueCallee(obj.expr)
 	exprFunc, isFn := callee.(*ExprFunc)
 
 	argGen := func(x int) (string, error) {
@@ -8641,6 +8691,7 @@ type ExprVar struct {
 	typ   *types.Type
 
 	Name string // name of the variable
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -8904,6 +8955,7 @@ type ExprParam struct {
 	typ *types.Type
 
 	Name string // name of the parameter
+	TextArea
 }
 
 // String returns a short representation of this expression.
@@ -9616,6 +9668,7 @@ type ExprIf struct {
 	Condition  interfaces.Expr
 	ThenBranch interfaces.Expr // could be an ExprBranch
 	ElseBranch interfaces.Expr // could be an ExprBranch
+	TextArea
 }
 
 // String returns a short representation of this expression.

lang/ast/util.go

@@ -327,16 +327,16 @@ func getScope(node interfaces.Expr) (*interfaces.Scope, error) {
 	}
 }
 
-// trueCallee is a helper function because ExprTopLevel and ExprSingleton are
+// TrueCallee is a helper function because ExprTopLevel and ExprSingleton are
 // sometimes added around builtins. This makes it difficult for the type checker
 // to check if a particular builtin is the callee or not. This function removes
 // the ExprTopLevel and ExprSingleton wrappers, if they exist.
-func trueCallee(apparentCallee interfaces.Expr) interfaces.Expr {
+func TrueCallee(apparentCallee interfaces.Expr) interfaces.Expr {
 	switch x := apparentCallee.(type) {
 	case *ExprTopLevel:
-		return trueCallee(x.Definition)
+		return TrueCallee(x.Definition)
 	case *ExprSingleton:
-		return trueCallee(x.Definition)
+		return TrueCallee(x.Definition)
 	default:
 		return apparentCallee
 	}
@@ -383,7 +383,7 @@ func lambdaScopeFeedback(scope *interfaces.Scope, logf func(format string, v ...
 	names := []string{}
 	for name, val := range scope.Variables {
 		// XXX: Is this a valid way to filter?
-		if _, ok := trueCallee(val).(*ExprFunc); !ok {
+		if _, ok := TrueCallee(val).(*ExprFunc); !ok {
 			continue
 		}
 		names = append(names, name)

lang/gapi/gapi.go

@@ -274,6 +274,12 @@ func (obj *GAPI) Cli(info *gapi.Info) (*gapi.Deploy, error) {
 		unificationStrategy[unification.StrategyOptimizationsKey] = strings.Join(args.UnifyOptimizations, ",")
 	}
 
+	fmt.Println("The Interpolated Tree: %+v")
+	iast.Apply(func (n interfaces.Node) error {
+		fmt.Println(n)
+		return nil
+	})
+
 	if !args.SkipUnify {
 		// apply type unification
 		unificationLogf := func(format string, v ...interface{}) {
@@ -304,7 +310,8 @@ func (obj *GAPI) Cli(info *gapi.Info) (*gapi.Deploy, error) {
 			if args.OnlyUnify {
 				logf("type unification failed after %s", formatted)
 			}
-			return nil, errwrap.Wrapf(unifyErr, "could not unify types")
+			callee := ast.TrueCallee(unifyErr.(*interfaces.UnificationInvariant).Expr)
+			return nil, errwrap.Wrapf(unifyErr, "could not unify types [[ in expression: %s ]]", callee)
 		}
 
 		if args.OnlyUnify {

lang/interfaces/unification.go

@@ -48,6 +48,13 @@ type UnificationInvariant struct { // formerly the SamInvariant
 
 	// Actual is one of the two types to unify.
 	Actual *types.Type
+
+	// An error string to pass along with this
+	Err string
+}
+
+func (obj *UnificationInvariant) Error() string {
+	return obj.Err
 }
 
 // GenericCheck is the generic implementation of the Check Expr interface call.