Add Seq template func

Very similar to GNU's seq.

Fixes #552

Conflicts:
	tpl/template.go
This commit is contained in:
bep 2015-02-24 10:56:16 +01:00 committed by spf13
parent 358dcce7a6
commit 0be2aade99
3 changed files with 113 additions and 0 deletions

View file

@ -19,6 +19,7 @@ import (
"encoding/hex"
"errors"
"fmt"
"github.com/spf13/cast"
bp "github.com/spf13/hugo/bufferpool"
jww "github.com/spf13/jwalterweatherman"
"github.com/spf13/viper"
@ -159,6 +160,74 @@ func Md5String(f string) string {
return hex.EncodeToString(h.Sum([]byte{}))
}
// Seq creates a sequence of integers.
// It's named and used as GNU's seq.
// Examples:
// 3 => 1, 2, 3
// 1 2 4 => 1, 3
// -3 => -1, -2, -3
// 1 4 => 1, 2, 3, 4
// 1 -2 => 1, 0, -1, -2
func Seq(args ...interface{}) ([]int, error) {
if len(args) < 1 || len(args) > 3 {
return nil, errors.New("Seq, invalid number of args: 'first' 'increment' (optional) 'last' (optional)")
}
intArgs := cast.ToIntSlice(args)
var inc int = 1
var last int
var first = intArgs[0]
if len(intArgs) == 1 {
last = first
if last == 0 {
return []int{}, nil
} else if last > 0 {
first = 1
} else {
first = -1
inc = -1
}
} else if len(intArgs) == 2 {
last = intArgs[1]
if last < first {
inc = -1
}
} else {
inc = intArgs[1]
last = intArgs[2]
if inc == 0 {
return nil, errors.New("'increment' must not be 0")
}
if first < last && inc < 0 {
return nil, errors.New("'increment' must be > 0")
}
if first > last && inc > 0 {
return nil, errors.New("'increment' must be < 0")
}
}
size := int(((last - first) / inc) + 1)
// sanity check
if size > 2000 {
return nil, errors.New("size of result exeeds limit")
}
seq := make([]int, size)
val := first
for i := 0; ; i++ {
seq[i] = val
val += inc
if (inc < 0 && val < last) || (inc > 0 && val > last) {
break
}
}
return seq, nil
}
// DoArithmetic performs arithmetic operations (+,-,*,/) using reflection to
// determine the type of the two terms.
func DoArithmetic(a, b interface{}, op rune) (interface{}, error) {

View file

@ -133,6 +133,49 @@ func TestMd5StringEmpty(t *testing.T) {
}
}
func TestSeq(t *testing.T) {
for i, this := range []struct {
in []interface{}
expect interface{}
}{
{[]interface{}{-2, 5}, []int{-2, -1, 0, 1, 2, 3, 4, 5}},
{[]interface{}{1, 2, 4}, []int{1, 3}},
{[]interface{}{1}, []int{1}},
{[]interface{}{3}, []int{1, 2, 3}},
{[]interface{}{3.2}, []int{1, 2, 3}},
{[]interface{}{0}, []int{}},
{[]interface{}{-1}, []int{-1}},
{[]interface{}{-3}, []int{-1, -2, -3}},
{[]interface{}{3, -2}, []int{3, 2, 1, 0, -1, -2}},
{[]interface{}{6, -2, 2}, []int{6, 4, 2}},
{[]interface{}{1, 0, 2}, false},
{[]interface{}{1, -1, 2}, false},
{[]interface{}{2, 1, 1}, false},
{[]interface{}{2, 1, 1, 1}, false},
{[]interface{}{2001}, false},
{[]interface{}{}, false},
{[]interface{}{t}, []int{}},
{nil, false},
} {
result, err := Seq(this.in...)
if b, ok := this.expect.(bool); ok && !b {
if err == nil {
t.Errorf("[%d] TestSeq didn't return an expected error %s", i)
}
} else {
if err != nil {
t.Errorf("[%d] failed: %s", i, err)
continue
}
if !reflect.DeepEqual(result, this.expect) {
t.Errorf("[%d] TestSeq got %v but expected %v", i, result, this.expect)
}
}
}
}
func TestDoArithmetic(t *testing.T) {
for i, this := range []struct {
a interface{}

View file

@ -1340,6 +1340,7 @@ func init() {
"getJson": GetJSON,
"getCSV": GetCSV,
"getCsv": GetCSV,
"seq": helpers.Seq,
}
}