lang: Refactor all the highlight helping together

Keep this cleaner and add a bit more.

lang/ast/structs.go

@@ -6854,7 +6854,7 @@ func (obj *StmtInclude) SetScope(scope *interfaces.Scope) error {
 			classScopeFeedback(scope, obj.data.Logf)
 		}
 		err := fmt.Errorf("class `%s` does not exist in this scope", obj.Name)
-		return highlightHelper(obj, obj.data.Logf, err)
+		return interfaces.HighlightHelper(obj, obj.data.Logf, err)
 	}
 	class, ok := stmt.(*StmtClass)
 	if !ok {
@@ -6863,7 +6863,8 @@ func (obj *StmtInclude) SetScope(scope *interfaces.Scope) error {
 
 	// Is it even possible for the signatures to not match?
 	if len(class.Args) != len(obj.Args) {
-		return fmt.Errorf("class `%s` expected %d args but got %d", obj.Name, len(class.Args), len(obj.Args))
+		err := fmt.Errorf("class `%s` expected %d args but got %d", obj.Name, len(class.Args), len(obj.Args))
+		return interfaces.HighlightHelper(obj, obj.data.Logf, err)
 	}
 
 	if obj.class != nil {
@@ -10514,7 +10515,7 @@ func (obj *ExprCall) SetScope(scope *interfaces.Scope, sctx map[string]interface
 					lambdaScopeFeedback(obj.scope, obj.data.Logf)
 				}
 				err := fmt.Errorf("lambda `$%s` does not exist in this scope", prefixedName)
-				return highlightHelper(obj, obj.data.Logf, err)
+				return interfaces.HighlightHelper(obj, obj.data.Logf, err)
 			}
 			target = f
 		}
@@ -10531,7 +10532,7 @@ func (obj *ExprCall) SetScope(scope *interfaces.Scope, sctx map[string]interface
 				functionScopeFeedback(obj.scope, obj.data.Logf)
 			}
 			err := fmt.Errorf("func `%s` does not exist in this scope", prefixedName)
-			return highlightHelper(obj, obj.data.Logf, err)
+			return interfaces.HighlightHelper(obj, obj.data.Logf, err)
 		}
 		target = f
 	}
@@ -11284,7 +11285,7 @@ func (obj *ExprVar) SetScope(scope *interfaces.Scope, sctx map[string]interfaces
 			variableScopeFeedback(obj.scope, obj.data.Logf)
 		}
 		err := fmt.Errorf("var `$%s` does not exist in this scope", obj.Name)
-		return highlightHelper(obj, obj.data.Logf, err)
+		return interfaces.HighlightHelper(obj, obj.data.Logf, err)
 	}
 
 	obj.scope.Variables[obj.Name] = target
@@ -11345,7 +11346,7 @@ func (obj *ExprVar) Infer() (*types.Type, []*interfaces.UnificationInvariant, er
 	expr, exists := obj.scope.Variables[obj.Name]
 	if !exists {
 		err := fmt.Errorf("var `%s` does not exist in this scope", obj.Name)
-		return nil, nil, highlightHelper(obj, obj.data.Logf, err)
+		return nil, nil, interfaces.HighlightHelper(obj, obj.data.Logf, err)
 	}
 
 	// This child call to Infer is an outlier to the common pattern where

lang/ast/util.go

@@ -574,16 +574,3 @@ func classScopeFeedback(scope *interfaces.Scope, logf func(format string, v ...i
 		logf("class %s", name)
 	}
 }
-
-// highlightHelper give the user better file/line number feedback.
-func highlightHelper(node interfaces.Node, logf func(format string, v ...interface{}), err error) error {
-	displayer, ok := node.(interfaces.TextDisplayer)
-	if ok {
-		if highlight := displayer.HighlightText(); highlight != "" {
-			logf("%s: %s", err.Error(), highlight)
-		}
-		//return fmt.Errorf("%s: %s", err.Error(), displayer.Byline())
-	}
-
-	return err
-}

lang/interfaces/textarea.go

@@ -197,3 +197,16 @@ func (obj *Textarea) HighlightText() string {
 
 	return result.String()
 }
+
+// HighlightHelper gives the user better file/line number feedback.
+func HighlightHelper(node Node, logf func(format string, v ...interface{}), err error) error {
+	displayer, ok := node.(TextDisplayer)
+	if !ok {
+		return err
+	}
+
+	if highlight := displayer.HighlightText(); highlight != "" {
+		logf("%s: %s", err.Error(), highlight)
+	}
+	return fmt.Errorf("%s: %s", err.Error(), displayer.Byline())
+}

lang/interpret_test/TestAstFunc1/graph8.txtar

@@ -6,4 +6,4 @@ if true {
 	$b = true
 }
 -- OUTPUT --
-# err: errSetScope: var `$b` does not exist in this scope
+# err: errSetScope: var `$b` does not exist in this scope: /main.mcl @ 2:4-2:5

lang/interpret_test/TestAstFunc1/importscope1.txtar

@@ -16,4 +16,4 @@ class xclass {
 	}
 }
 -- OUTPUT --
-# err: errSetScope: func `os.is_family_debian` does not exist in this scope
+# err: errSetScope: func `os.is_family_debian` does not exist in this scope: /second.mcl @ 5:12-5:33

lang/interpret_test/TestAstFunc2/class-capture7.txtar

@@ -9,4 +9,4 @@ include foo
 # This sort of thing is not currently supported, and not sure if it ever will.
 include bar # nope!
 -- OUTPUT --
-# err: errSetScope: class `bar` does not exist in this scope
+# err: errSetScope: class `bar` does not exist in this scope: /main.mcl @ 9:1-9:12

lang/interpret_test/TestAstFunc2/class-include-as-class2.txtar

@@ -14,4 +14,4 @@ class c1($b) {
 include c1 as i1
 include i1.inner
 -- OUTPUT --
-# err: errSetScope: class `c1` expected 1 args but got 0
+# err: errSetScope: class `c1` expected 1 args but got 0: /main.mcl @ 13:1-13:17

lang/interpret_test/TestAstFunc2/clear-env-on-var.txtar

@@ -7,4 +7,4 @@ $f = func($x) {
 $name = $f("foo")
 test "${name}" {}
 -- OUTPUT --
-# err: errSetScope: var `$x` does not exist in this scope
+# err: errSetScope: var `$x` does not exist in this scope: /main.mcl @ 1:8-1:9

lang/interpret_test/TestAstFunc2/func-gen1.txtar

@@ -11,4 +11,4 @@ include funcgen1
 $x1 = fun1()	# not funcgen1.fun1 since it's *not* an import!
 test "${x1}" {}	# hi
 -- OUTPUT --
-# err: errSetScope: func `fun1` does not exist in this scope
+# err: errSetScope: func `fun1` does not exist in this scope: /main.mcl @ 10:7-10:13

lang/interpret_test/TestAstFunc2/func-gen2.txtar

@@ -14,4 +14,4 @@ include funcgen2
 $x2 = fun2()	# not funcgen2.fun2 since it's *not* an import!
 test "${x2}" {}	# hello world
 -- OUTPUT --
-# err: errSetScope: func `fun2` does not exist in this scope
+# err: errSetScope: func `fun2` does not exist in this scope: /main.mcl @ 13:7-13:13

lang/interpret_test/TestAstFunc2/import-scope-vars2-fail.txtar

@@ -11,4 +11,4 @@ $x = "this is x.mcl"
 import "x.mcl" as f
 $y = $f.x + " and this is y.mcl"
 -- OUTPUT --
-# err: errSetScope: var `$g.x` does not exist in this scope
+# err: errSetScope: var `$g.x` does not exist in this scope: /main.mcl @ 3:6-3:14

lang/unification/fastsolver/fastsolver.go

@@ -143,6 +143,10 @@ func (obj *FastInvariantSolver) Solve(ctx context.Context, data *unification.Dat
 				obj.Logf("%s: %s", err.Error(), highlight)
 			}
 			return nil, fmt.Errorf("%s: %s", err.Error(), displayer.Byline())
+
+			// XXX: when we have fully populated all the position
+			// information, we could replace the above code with:
+			//return nil, interfaces.HighlightHelper(x.Node, obj.Logf, err)
 		}
 		if obj.Debug {
 			e1, e2 := unificationUtil.Extract(x.Expect), unificationUtil.Extract(x.Actual)
@@ -165,7 +169,9 @@ func (obj *FastInvariantSolver) Solve(ctx context.Context, data *unification.Dat
 
 		// TODO: collect all of these errors and return them together?
 		if t1.HasUni() { // || t2.HasUni()
-			return nil, fmt.Errorf("expr: %s is ambiguous: %s", x.Expr, u(t1))
+			err := fmt.Errorf("expr: %s is ambiguous: %s", x.Expr, u(t1))
+			return nil, interfaces.HighlightHelper(x.Node, obj.Logf, err)
+
 		}
 
 		//if err := t1.Cmp(t2); err != nil { // for development/debugging