lang: core, funcs, types: Add ctx to simple func

Plumb through the standard context.Context so that a function can be
cancelled if someone requests this. It makes it less awkward to write
simple functions that might depend on io or network access.

lang/core/datetime/format_func.go

@@ -30,6 +30,7 @@
 package coredatetime
 
 import (
+	"context"
 	"fmt"
 	"time"
 
@@ -48,7 +49,7 @@ func init() {
 // has to be defined like specified by the golang "time" package. The time is
 // the number of seconds since the epoch, and matches what comes from our Now
 // function. Golang documentation: https://golang.org/pkg/time/#Time.Format
-func Format(input []types.Value) (types.Value, error) {
+func Format(ctx context.Context, input []types.Value) (types.Value, error) {
 	epochDelta := input[0].Int()
 	if epochDelta < 0 {
 		return nil, fmt.Errorf("epoch delta must be positive")

lang/core/datetime/format_func_test.go

@@ -32,6 +32,7 @@
 package coredatetime
 
 import (
+	"context"
 	"testing"
 
 	"github.com/purpleidea/mgmt/lang/types"
@@ -41,7 +42,7 @@ func TestFormat(t *testing.T) {
 	inputVal := &types.IntValue{V: 1443158163}
 	inputFormat := &types.StrValue{V: "2006"}
 
-	val, err := Format([]types.Value{inputVal, inputFormat})
+	val, err := Format(context.Background(), []types.Value{inputVal, inputFormat})
 	if err != nil {
 		t.Error(err)
 	}

lang/core/datetime/hour_func.go

@@ -30,6 +30,7 @@
 package coredatetime
 
 import (
+	"context"
 	"fmt"
 	"time"
 
@@ -47,7 +48,7 @@ func init() {
 // Hour returns the hour of the day corresponding to the input time. The time is
 // the number of seconds since the epoch, and matches what comes from our Now
 // function.
-func Hour(input []types.Value) (types.Value, error) {
+func Hour(ctx context.Context, input []types.Value) (types.Value, error) {
 	epochDelta := input[0].Int()
 	if epochDelta < 0 {
 		return nil, fmt.Errorf("epoch delta must be positive")

lang/core/datetime/print_func.go

@@ -30,6 +30,7 @@
 package coredatetime
 
 import (
+	"context"
 	"fmt"
 	"time"
 
@@ -41,7 +42,7 @@ func init() {
 	// FIXME: consider renaming this to printf, and add in a format string?
 	simple.ModuleRegister(ModuleName, "print", &types.FuncValue{
 		T: types.NewType("func(a int) str"),
-		V: func(input []types.Value) (types.Value, error) {
+		V: func(ctx context.Context, input []types.Value) (types.Value, error) {
 			epochDelta := input[0].Int()
 			if epochDelta < 0 {
 				return nil, fmt.Errorf("epoch delta must be positive")

lang/core/datetime/weekday_func.go

@@ -30,6 +30,7 @@
 package coredatetime
 
 import (
+	"context"
 	"fmt"
 	"strings"
 	"time"
@@ -48,7 +49,7 @@ func init() {
 // Weekday returns the lowercased day of the week corresponding to the input
 // time. The time is the number of seconds since the epoch, and matches what
 // comes from our Now function.
-func Weekday(input []types.Value) (types.Value, error) {
+func Weekday(ctx context.Context, input []types.Value) (types.Value, error) {
 	epochDelta := input[0].Int()
 	if epochDelta < 0 {
 		return nil, fmt.Errorf("epoch delta must be positive")