lang: yamldecode and yamlencode functions

go.mod

@@ -108,6 +108,7 @@ require (
 	github.com/xiang90/probing v0.0.0-20160813154853-07dd2e8dfe18 // indirect
 	github.com/xlab/treeprint v0.0.0-20161029104018-1d6e34225557
 	github.com/zclconf/go-cty v0.0.0-20190516203816-4fecf87372ec
+	github.com/zclconf/go-cty-yaml v0.1.0
 	go.uber.org/atomic v1.3.2 // indirect
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.9.1 // indirect

go.sum

@@ -405,6 +405,8 @@ github.com/zclconf/go-cty v0.0.0-20190426224007-b18a157db9e2 h1:Ai1LhlYNEqE39zGU
 github.com/zclconf/go-cty v0.0.0-20190426224007-b18a157db9e2/go.mod h1:xnAOWiHeOqg2nWS62VtQ7pbOu17FtxJNW8RLEih+O3s=
 github.com/zclconf/go-cty v0.0.0-20190516203816-4fecf87372ec h1:MSeYjmyjucsFbecMTxg63ASg23lcSARP/kr9sClTFfk=
 github.com/zclconf/go-cty v0.0.0-20190516203816-4fecf87372ec/go.mod h1:xnAOWiHeOqg2nWS62VtQ7pbOu17FtxJNW8RLEih+O3s=
+github.com/zclconf/go-cty-yaml v0.1.0 h1:OP5nkApyAuXB88t8mRUqxD9gbKZocSLuVovrBAt8z10=
+github.com/zclconf/go-cty-yaml v0.1.0/go.mod h1:Lk26EcRlO3XbaQ8U2fxIJbEtbgEteSZFUpEr3XFTtsU=
 go.opencensus.io v0.18.0 h1:Mk5rgZcggtbvtAun5aJzAtjKKN/t0R3jJPlWILlv938=
 go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
 go.uber.org/atomic v1.3.2 h1:2Oa65PReHzfn29GpvgsYwloV9AVFHPDk8tYxt2c2tr4=

lang/functions.go

@@ -3,6 +3,7 @@ package lang
 import (
 	"fmt"
 
+	ctyyaml "github.com/zclconf/go-cty-yaml"
 	"github.com/zclconf/go-cty/cty"
 	"github.com/zclconf/go-cty/cty/function"
 	"github.com/zclconf/go-cty/cty/function/stdlib"
@@ -115,6 +116,8 @@ func (s *Scope) Functions() map[string]function.Function {
 			"urlencode":        funcs.URLEncodeFunc,
 			"uuid":             funcs.UUIDFunc,
 			"values":           funcs.ValuesFunc,
+			"yamldecode":       ctyyaml.YAMLDecodeFunc,
+			"yamlencode":       ctyyaml.YAMLEncodeFunc,
 			"zipmap":           funcs.ZipmapFunc,
 		}
 

lang/functions_test.go

@@ -752,6 +752,29 @@ func TestFunctions(t *testing.T) {
 			},
 		},
 
+		"yamldecode": {
+			{
+				`yamldecode("true")`,
+				cty.True,
+			},
+		},
+
+		"yamlencode": {
+			{
+				`yamlencode(["foo", "bar", true])`,
+				cty.StringVal("- \"foo\"\n- \"bar\"\n- true\n"),
+			},
+			{
+				`yamlencode({a = "b", c = "d"})`,
+				cty.StringVal("\"a\": \"b\"\n\"c\": \"d\"\n"),
+			},
+			{
+				`yamlencode(true)`,
+				// the ... here is an "end of document" marker, produced for implied primitive types only
+				cty.StringVal("true\n...\n"),
+			},
+		},
+
 		"zipmap": {
 			{
 				`zipmap(["hello", "bar"], ["world", "baz"])`,