From 7efeb9c56fe6ff62b9fc9f7a106915aca2112b7a Mon Sep 17 00:00:00 2001
From: Qi Xiao <xiaqqaix@gmail.com>
Date: Fri, 19 Feb 2016 17:46:21 +0100
Subject: [PATCH] Remove ContextualError.

---
 edit/editor.go           |  6 ++---
 eval/eval.go             |  4 +--
 main.go                  |  2 --
 util/contextual_error.go | 55 ----------------------------------------
 util/pos_error.go        | 26 ++++++++++++++++++-
 5 files changed, 28 insertions(+), 65 deletions(-)
 delete mode 100644 util/contextual_error.go

diff --git a/edit/editor.go b/edit/editor.go
index 3df10629..cfcedeee 100644
--- a/edit/editor.go
+++ b/edit/editor.go
@@ -138,8 +138,8 @@ func (ed *Editor) refresh(fullRefresh bool, tips bool) error {
 				if tips && !atEnd(err, len(src)) {
 					ed.addTip("compiler error: %s", err)
 				}
-				if err, ok := err.(*util.ContextualError); ok {
-					p := err.Pos()
+				if err, ok := err.(*util.PosError); ok {
+					p := err.Begin
 					for i, token := range ed.tokens {
 						if token.Node.Begin() <= p && p < token.Node.End() {
 							ed.tokens[i].MoreStyle += styleForCompilerError
@@ -160,8 +160,6 @@ func (ed *Editor) refresh(fullRefresh bool, tips bool) error {
 
 func atEnd(e error, n int) bool {
 	switch e := e.(type) {
-	case *util.ContextualError:
-		return e.Pos() == n
 	case *util.PosError:
 		return e.Begin == n
 	case *util.Errors:
diff --git a/eval/eval.go b/eval/eval.go
index 50eb2b2e..85e5d811 100644
--- a/eval/eval.go
+++ b/eval/eval.go
@@ -185,9 +185,7 @@ func (ec *EvalCtx) PCall(f Caller, args []Value) (ex error) {
 // errorf stops the ec.eval immediately by panicking with a diagnostic message.
 // The panic is supposed to be caught by ec.eval.
 func (ec *EvalCtx) errorf(p int, format string, args ...interface{}) {
-	throw(util.NewContextualError(
-		fmt.Sprintf("%s (%s)", ec.name, ec.context), "error",
-		ec.text, p, format, args...))
+	throw(&util.PosError{p, p, fmt.Errorf(format, args...)})
 }
 
 // SourceText evaluates a chunk of elvish source.
diff --git a/main.go b/main.go
index ac0eac78..ed2eb552 100644
--- a/main.go
+++ b/main.go
@@ -225,8 +225,6 @@ func printError(err error) {
 		return
 	}
 	switch err := err.(type) {
-	case *util.ContextualError:
-		fmt.Print(err.Pprint())
 	case *util.Errors:
 		for _, e := range err.Errors {
 			printError(e)
diff --git a/util/contextual_error.go b/util/contextual_error.go
deleted file mode 100644
index 133ddd8d..00000000
--- a/util/contextual_error.go
+++ /dev/null
@@ -1,55 +0,0 @@
-package util
-
-import (
-	"bytes"
-	"fmt"
-	"strings"
-)
-
-// ContextualError is an error associated with a particular point in a source
-// text.
-type ContextualError struct {
-	srcname string
-	title   string
-	pos     int
-	line    string
-	lineno  int
-	colno   int
-	msg     string
-}
-
-// NewContextualError creates a new ContextualError.
-func NewContextualError(srcname, title, text string, pos int, format string, args ...interface{}) *ContextualError {
-	lineno, colno, line := FindContext(text, pos)
-	return &ContextualError{srcname, title, pos, line, lineno, colno, fmt.Sprintf(format, args...)}
-}
-
-func (e *ContextualError) Pos() int {
-	return e.pos
-}
-
-// Error implements the error interface. It returns a compact representation of
-// the error.
-func (e *ContextualError) Error() string {
-	return fmt.Sprintf("%s:%d:%d %s:%s", e.srcname, e.lineno, e.colno, e.title, e.msg)
-}
-
-// Pprint pretty-prints a ContextualError with the error position, the affected
-// line an arrow pointing to the point of error and the error message, with
-// colors.
-func (e *ContextualError) Pprint() string {
-	buf := new(bytes.Buffer)
-	// Position info
-	fmt.Fprintf(buf, "\033[1m%s:%d:%d: ", e.srcname, e.lineno+1, e.colno+1)
-	// "error:"
-	fmt.Fprintf(buf, "\033[31m%s: ", e.title)
-	// Message
-	fmt.Fprintf(buf, "\033[m\033[1m%s\033[m\n", e.msg)
-	// Context: line
-	// TODO Handle long lines
-	fmt.Fprintf(buf, "%s\n", e.line)
-	// Context: arrow
-	// TODO Handle multi-width characters
-	fmt.Fprintf(buf, "%s\033[32;1m^\033[m\n", strings.Repeat(" ", e.colno))
-	return buf.String()
-}
diff --git a/util/pos_error.go b/util/pos_error.go
index a3f6d76c..5d61b7d0 100644
--- a/util/pos_error.go
+++ b/util/pos_error.go
@@ -1,6 +1,10 @@
 package util
 
-import "fmt"
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
 
 // PosError is an error associated with a position range.
 type PosError struct {
@@ -12,3 +16,23 @@ type PosError struct {
 func (pe *PosError) Error() string {
 	return fmt.Sprintf("%d-%d: %s", pe.Begin, pe.End, pe.Err.Error())
 }
+
+// Pprint pretty-prints a PosError with a header indicating the source and type
+// of the error, the error text and the affected line with an additional line
+// that points an arrow at the affected column.
+func (pe *PosError) Pprint(srcname, errtype, src string) string {
+	lineno, colno, line := FindContext(src, pe.Begin)
+
+	buf := new(bytes.Buffer)
+	// Source and type of the error
+	fmt.Fprintf(buf, "\033[1m%s:%d:%d: \033[31m%s:", srcname, lineno+1, colno+1, errtype)
+	// Message
+	fmt.Fprintf(buf, "\033[m\033[1m%s\033[m\n", pe.Err.Error())
+	// Affected line
+	// TODO Handle long lines
+	fmt.Fprintf(buf, "%s\n", line)
+	// Column indicator
+	// TODO Handle multi-width characters
+	fmt.Fprintf(buf, "%s\033[32;1m^\033[m\n", strings.Repeat(" ", colno))
+	return buf.String()
+}