schemahcl: add support for regexpescape hcl function

schemahcl/stdlib.go

@@ -10,6 +10,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -141,6 +142,7 @@ func stdFuncs() map[string]function.Function {
 		"range":           stdlib.RangeFunc,
 		"regex":           stdlib.RegexFunc,
 		"regexall":        stdlib.RegexAllFunc,
+		"regexpescape":    regexpEscape,
 		"regexreplace":    stdlib.RegexReplaceFunc,
 		"reverse":         stdlib.ReverseListFunc,
 		"setintersection": stdlib.SetIntersectionFunc,
@@ -442,6 +444,20 @@ var (
 			return cty.False, nil
 		},
 	})
+
+	regexpEscape = function.New(&function.Spec{
+		Description: `Return a string that escapes all regular expression metacharacters in the provided text.`,
+		Params: []function.Parameter{
+			{
+				Name: "str",
+				Type: cty.String,
+			},
+		},
+		Type: function.StaticReturnType(cty.String),
+		Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+			return cty.StringVal(regexp.QuoteMeta(args[0].AsString())), nil
+		},
+	})
 )
 
 // MakeFileFunc returns a function that reads a file

schemahcl/stdlib_test.go

@@ -156,6 +156,15 @@ func TestEndsWithFunc(t *testing.T) {
 	require.Equal(t, cty.True, got)
 }
 
+func TestRegexpEscapeFunc(t *testing.T) {
+	got, err := regexpEscape.Call([]cty.Value{cty.StringVal("a|b|c")})
+	require.NoError(t, err)
+	require.Equal(t, "a\\|b\\|c", got.AsString())
+	got, err = regexpEscape.Call([]cty.Value{cty.StringVal("abc")})
+	require.NoError(t, err)
+	require.Equal(t, "abc", got.AsString())
+}
+
 func TestMakeFileFunc(t *testing.T) {
 	fn := MakeFileFunc("testdata")
 	_, err := fn.Call([]cty.Value{cty.StringVal("foo")})
@@ -168,6 +177,36 @@ func TestMakeFileFunc(t *testing.T) {
 	require.Equal(t, "person \"rotemtam\" {\n  hobby = var.hobby\n}", v.AsString())
 }
 
+func Example_RegexpEscapeFunc() {
+	for _, f := range []string{
+		`v  = regexpescape("a|b|c")`,
+		`v  = regexpescape("abc")`,
+		`v = regexpescape(<<TAB
+id | name
+---+-----
+1  | foo
+TAB
+)`,
+	} {
+		var d struct {
+			V string `spec:"v"`
+		}
+		if err := New().EvalBytes([]byte(f), &d, nil); err != nil {
+			fmt.Println("failed to evaluate:", err)
+			return
+		}
+		fmt.Printf("%s\n\n", d.V)
+	}
+	// Output:
+	// a\|b\|c
+	//
+	// abc
+	//
+	// id \| name
+	// ---\+-----
+	// 1  \| foo
+}
+
 func Example_PrintFunc() {
 	for _, f := range []string{
 		`v  = print("a")`,