From 8a11afb78f52e7f275f59ef6fdb177ef9b287aa4 Mon Sep 17 00:00:00 2001
From: xushiwei <xushiweizh@gmail.com>
Date: Sun, 17 May 2020 16:22:43 +0800
Subject: [PATCH] interpreter.Context

---
 tpl/interpreter.util/call.go        | 15 ++++++++-------
 tpl/interpreter/interpreter.go      | 19 +++++++++++++------
 tpl/interpreter/interpreter_test.go | 15 +++++++++++----
 tpl/qlang/cl/ctrl.go                |  3 ++-
 4 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/tpl/interpreter.util/call.go b/tpl/interpreter.util/call.go
index fce24aa..73edeb1 100644
--- a/tpl/interpreter.util/call.go
+++ b/tpl/interpreter.util/call.go
@@ -20,13 +20,6 @@ var (
 
 // -----------------------------------------------------------------------------
 
-// Context represents the context of an interpreter.
-type Context struct {
-	Src interface{} // []tpl.Token
-	Pos token.Pos
-	End token.Pos
-}
-
 // FileLine represents file name and line number.
 type FileLine struct {
 	File string
@@ -53,6 +46,14 @@ type Engine interface {
 	Source(src interface{}) []byte
 }
 
+// Context represents the context of an interpreter.
+type Context struct {
+	Src    interface{} // []tpl.Token
+	Pos    token.Pos
+	End    token.Pos
+	Engine Engine
+}
+
 // Call calls a fn.
 func Call(stk Stack, fn interface{}, arity int) error {
 	tfn := reflect.TypeOf(fn)
diff --git a/tpl/interpreter/interpreter.go b/tpl/interpreter/interpreter.go
index 053ee25..0a4ed46 100644
--- a/tpl/interpreter/interpreter.go
+++ b/tpl/interpreter/interpreter.go
@@ -15,6 +15,7 @@ import (
 var (
 	typeIntf    = reflect.TypeOf((*interface{})(nil)).Elem()
 	typeEng     = reflect.TypeOf((*interpreter.Engine)(nil)).Elem()
+	typeCtx     = reflect.TypeOf((*interpreter.Context)(nil))
 	zeroIntfVal = reflect.Zero(typeIntf)
 )
 
@@ -263,6 +264,8 @@ func New(ipt interpreter.Interface, options *Options) (p *Engine, err error) {
 						args[1] = reflect.ValueOf(g.Len())
 					} else {
 						switch targ1 {
+						case typeCtx:
+							args[1] = p.ctxValue(tokens)
 						case typeIntf:
 							if len(tokens) == 0 { // use nil as empty source
 								args[1] = zeroIntfVal
@@ -281,12 +284,7 @@ func New(ipt interpreter.Interface, options *Options) (p *Engine, err error) {
 					}
 				}
 				if n == 3 {
-					ctx := &interpreter.Context{Src: tokens}
-					if len(tokens) > 0 {
-						ctx.Pos = tokens[0].Pos
-						ctx.End = tokens[len(tokens)-1].End()
-					}
-					args[2] = reflect.ValueOf(ctx)
+					args[2] = p.ctxValue(tokens)
 				}
 				ret := reflect.ValueOf(fn).Call(args)
 				if len(ret) > 0 {
@@ -321,6 +319,15 @@ func New(ipt interpreter.Interface, options *Options) (p *Engine, err error) {
 	return
 }
 
+func (p *Engine) ctxValue(tokens []tpl.Token) reflect.Value {
+	ctx := &interpreter.Context{Src: tokens, Engine: interpreter.Engine(p)}
+	if len(tokens) > 0 {
+		ctx.Pos = tokens[0].Pos
+		ctx.End = tokens[len(tokens)-1].End()
+	}
+	return reflect.ValueOf(ctx)
+}
+
 // Source returns the source text of src.
 func (p *Engine) Source(src interface{}) (text []byte) {
 	if src == nil {
diff --git a/tpl/interpreter/interpreter_test.go b/tpl/interpreter/interpreter_test.go
index ae5367b..635969a 100644
--- a/tpl/interpreter/interpreter_test.go
+++ b/tpl/interpreter/interpreter_test.go
@@ -12,7 +12,7 @@ import (
 // -----------------------------------------------------------------------------
 
 const codeIf = `
-today = 3
+today = 5
 
 if today == 1 {
 	today = "Mon"
@@ -20,9 +20,16 @@ if today == 1 {
 	today = "Tue"
 } elif today == 3 {
 	today = "Wed"
+} else {
+	today = 0
+	for i = 0; i < 10; i++ {
+		today = today + i
+	}
 }
 
 println(today)
+
+panic("haha")
 `
 
 func TestIf(t *testing.T) {
@@ -32,14 +39,14 @@ func TestIf(t *testing.T) {
 	}
 
 	err = lang.SafeEval(codeIf)
-	if err != nil {
+	if err != nil && err.Error() != "line 19: runtime error: haha" {
 		t.Fatal(err)
 	}
 
 	v, _ := lang.Var("today")
 	fmt.Println(v)
-	if v != "Wed" {
-		t.Fatal("MaxPrime ret:", v)
+	if v != 45 {
+		t.Fatal("ret:", v)
 	}
 }
 
diff --git a/tpl/qlang/cl/ctrl.go b/tpl/qlang/cl/ctrl.go
index 875826a..bc39e31 100644
--- a/tpl/qlang/cl/ctrl.go
+++ b/tpl/qlang/cl/ctrl.go
@@ -44,9 +44,10 @@ func (p *Interpreter) And(e interpreter.Engine) {
 	evalCode(e, p, "term3", bCode)
 }
 
-func (p *Interpreter) If(e interpreter.Engine) {
+func (p *Interpreter) If(ctx *interpreter.Context) {
 
 	var elseCode interface{}
+	var e = ctx.Engine
 
 	stk := p.stk
 	elseArity := stk.popArity()