diff --git a/pkg/crypto/md5/md5.go b/pkg/crypto/md5/md5.go
new file mode 100644
index 0000000..76abba2
--- /dev/null
+++ b/pkg/crypto/md5/md5.go
@@ -0,0 +1,34 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo extract crypto/md5
+
+package md5
+
+import "crypto/md5"
+
+// The size of an MD5 checksum in bytes.
+const Size = 16
+
+// The blocksize of MD5 in bytes.
+const BlockSize = 64
+
+// Sum returns the MD5 checksum of the data.
+func Sum(data []byte) [Size]byte {
+	return md5.Sum(data)
+}
diff --git a/pkg/crypto/sha1/sha1.go b/pkg/crypto/sha1/sha1.go
new file mode 100644
index 0000000..f322690
--- /dev/null
+++ b/pkg/crypto/sha1/sha1.go
@@ -0,0 +1,34 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo extract crypto/sha1
+
+package sha1
+
+import "crypto/sha1"
+
+// The size of a SHA-1 checksum in bytes.
+const Size = 20
+
+// The blocksize of SHA-1 in bytes.
+const BlockSize = 64
+
+// Sum returns the SHA-1 checksum of the data.
+func Sum(data []byte) [Size]byte {
+	return sha1.Sum(data)
+}
diff --git a/pkg/crypto/sha256/sha256.go b/pkg/crypto/sha256/sha256.go
new file mode 100644
index 0000000..85088ca
--- /dev/null
+++ b/pkg/crypto/sha256/sha256.go
@@ -0,0 +1,42 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo extract crypto/sha256
+
+package sha256
+
+import "crypto/sha256"
+
+// The size of a SHA256 checksum in bytes.
+const Size = 32
+
+// The size of a SHA224 checksum in bytes.
+const Size224 = 28
+
+// The blocksize of SHA256 and SHA224 in bytes.
+const BlockSize = 64
+
+// Sum256 returns the SHA256 checksum of the data.
+func Sum256(data []byte) [Size]byte {
+	return sha256.Sum256(data)
+}
+
+// Sum224 returns the SHA224 checksum of the data.
+func Sum224(data []byte) (sum224 [Size224]byte) {
+	return sha256.Sum224(data)
+}
diff --git a/pkg/crypto/sha512/sha512.go b/pkg/crypto/sha512/sha512.go
new file mode 100644
index 0000000..3d5db60
--- /dev/null
+++ b/pkg/crypto/sha512/sha512.go
@@ -0,0 +1,61 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo extract crypto/sha512
+
+package sha512
+
+import "crypto/sha512"
+
+const (
+	// Size is the size, in bytes, of a SHA-512 checksum.
+	Size = 64
+
+	// Size224 is the size, in bytes, of a SHA-512/224 checksum.
+	Size224 = 28
+
+	// Size256 is the size, in bytes, of a SHA-512/256 checksum.
+	Size256 = 32
+
+	// Size384 is the size, in bytes, of a SHA-384 checksum.
+	Size384 = 48
+
+	// BlockSize is the block size, in bytes, of the SHA-512/224,
+	// SHA-512/256, SHA-384 and SHA-512 hash functions.
+	BlockSize = 128
+)
+
+// Sum512 returns the SHA512 checksum of the data.
+func Sum512(data []byte) [Size]byte {
+	return sha512.Sum512(data)
+}
+
+// Sum384 returns the SHA384 checksum of the data.
+func Sum384(data []byte) (sum384 [Size384]byte) {
+	return sha512.Sum384(data)
+}
+
+// Sum512_224 returns the Sum512/224 checksum of the data.
+func Sum512_224(data []byte) (sum224 [Size224]byte) {
+	return sha512.Sum512_224(data)
+}
+
+// Sum512_256 returns the Sum512/256 checksum of the data.
+func Sum512_256(data []byte) (sum256 [Size256]byte) {
+	return sha512.Sum512_256(data)
+}
diff --git a/pkg/doc.go b/pkg/doc.go
new file mode 100644
index 0000000..d4476d0
--- /dev/null
+++ b/pkg/doc.go
@@ -0,0 +1,36 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pkg define CUE builtin packages.
+//
+// The CUE core packages are different, but closely mimic the Go core packages.
+// The types, values, and functions are defined as their Go equivalence and
+// mapped to CUE types.
+//
+// Beware that some packages are defined in lesser-precision types than are
+// typically used in CUE and thus may lead to loss of precision.
+//
+// All packages in these subdirectories are hermetic. That is, the results
+// do not change based on environment conditions. That is:
+//
+//   - no reading of files contents
+//   - no querying of the file system of any kind
+//   - no communication on the network
+//   - no information about the type of environment
+//   - only reproduceable random generators
+//
+// Hermetic configurations allow for fast and advanced analysis that otherwise
+// would not be possible or practical. The cue "cmd" command can be used to
+// mix in non-hermetic influences into configurations.
+package pkg
diff --git a/pkg/encoding/hex/hex.go b/pkg/encoding/hex/hex.go
new file mode 100644
index 0000000..478632a
--- /dev/null
+++ b/pkg/encoding/hex/hex.go
@@ -0,0 +1,51 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -stripstr -exclude=Decode$,Encode$,EncodeToString,Dumper extract encoding/hex
+
+package hex
+
+import "encoding/hex"
+
+// EncodedLen returns the length of an encoding of n source bytes.
+// Specifically, it returns n * 2.
+func EncodedLen(n int) int {
+	return hex.EncodedLen(n)
+}
+
+// DecodedLen returns the length of a decoding of x source bytes.
+// Specifically, it returns x / 2.
+func DecodedLen(x int) int {
+	return hex.DecodedLen(x)
+}
+
+// Decode returns the bytes represented by the hexadecimal string s.
+//
+// Decode expects that src contains only hexadecimal
+// characters and that src has even length.
+// If the input is malformed, Decode returns
+// the bytes decoded before the error.
+func Decode(s string) ([]byte, error) {
+	return hex.DecodeString(s)
+}
+
+// Dump returns a string that contains a hex dump of the given data. The format
+// of the hex dump matches the output of `hexdump -C` on the command line.
+func Dump(data []byte) string {
+	return hex.Dump(data)
+}
diff --git a/pkg/encoding/json/json.go b/pkg/encoding/json/json.go
new file mode 100644
index 0000000..3bb0642
--- /dev/null
+++ b/pkg/encoding/json/json.go
@@ -0,0 +1,28 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Compact,Indent,arshal$ extract encoding/json
+
+package json
+
+import "encoding/json"
+
+// Valid reports whether data is a valid JSON encoding.
+func Valid(data []byte) bool {
+	return json.Valid(data)
+}
diff --git a/pkg/html/html.go b/pkg/html/html.go
new file mode 100644
index 0000000..548392b
--- /dev/null
+++ b/pkg/html/html.go
@@ -0,0 +1,40 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -stripstr extract html
+
+package html
+
+import "html"
+
+// Escape escapes special characters like "<" to become "&lt;". It
+// escapes only five such characters: <, >, &, ' and ".
+// UnescapeString(Escape(s)) == s always holds, but the converse isn't
+// always true.
+func Escape(s string) string {
+	return html.EscapeString(s)
+}
+
+// Unescape unescapes entities like "&lt;" to become "<". It unescapes a
+// larger range of entities than EscapeString escapes. For example, "&aacute;"
+// unescapes to "á", as does "&#225;" and "&#xE1;".
+// Unescape(EscapeString(s)) == s always holds, but the converse isn't
+// always true.
+func Unescape(s string) string {
+	return html.UnescapeString(s)
+}
diff --git a/pkg/math/big.go b/pkg/math/big.go
new file mode 100644
index 0000000..5f20b82
--- /dev/null
+++ b/pkg/math/big.go
@@ -0,0 +1,56 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude= extract math/big
+
+package math
+
+import "math/big"
+
+// Exponent and precision limits.
+const (
+	MaxExp  = 2147483647  // largest supported exponent
+	MinExp  = -2147483648 // smallest supported exponent
+	MaxPrec = 4294967295  // largest (theoretically) supported precision; likely memory-limited
+)
+
+// These constants define supported rounding modes.
+const (
+	ToNearestEven = 0 // == IEEE 754-2008 roundTiesToEven
+	ToNearestAway = 1 // == IEEE 754-2008 roundTiesToAway
+	ToZero        = 2 // == IEEE 754-2008 roundTowardZero
+	AwayFromZero  = 3 // no IEEE 754-2008 equivalent
+	ToNegativeInf = 4 // == IEEE 754-2008 roundTowardNegative
+	ToPositiveInf = 5 // == IEEE 754-2008 roundTowardPositive
+)
+
+// Constants describing the Accuracy of a Float.
+const (
+	Below = -1
+	Exact = 0
+	Above = 1
+)
+
+// Jacobi returns the Jacobi symbol (x/y), either +1, -1, or 0.
+// The y argument must be an odd integer.
+func Jacobi(x, y *big.Int) int {
+	return big.Jacobi(x, y)
+}
+
+// MaxBase is the largest number base accepted for string conversions.
+const MaxBase = 62
diff --git a/pkg/math/math.go b/pkg/math/math.go
new file mode 100644
index 0000000..c20e405
--- /dev/null
+++ b/pkg/math/math.go
@@ -0,0 +1,522 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=32,^Next,^Max,^Smallest,^Min,bits,Inf,NaN,Round,Trunc,Ceil,Floor$ extract math
+
+package math
+
+import "math"
+
+// Abs returns the absolute value of x.
+//
+// Special cases are:
+//	Abs(±Inf) = +Inf
+//	Abs(NaN) = NaN
+func Abs(x float64) float64 {
+	return math.Abs(x)
+}
+
+// Acosh returns the inverse hyperbolic cosine of x.
+//
+// Special cases are:
+//	Acosh(+Inf) = +Inf
+//	Acosh(x) = NaN if x < 1
+//	Acosh(NaN) = NaN
+func Acosh(x float64) float64 {
+	return math.Acosh(x)
+}
+
+// Asin returns the arcsine, in radians, of x.
+//
+// Special cases are:
+//	Asin(±0) = ±0
+//	Asin(x) = NaN if x < -1 or x > 1
+func Asin(x float64) float64 {
+	return math.Asin(x)
+}
+
+// Acos returns the arccosine, in radians, of x.
+//
+// Special case is:
+//	Acos(x) = NaN if x < -1 or x > 1
+func Acos(x float64) float64 {
+	return math.Acos(x)
+}
+
+// Asinh returns the inverse hyperbolic sine of x.
+//
+// Special cases are:
+//	Asinh(±0) = ±0
+//	Asinh(±Inf) = ±Inf
+//	Asinh(NaN) = NaN
+func Asinh(x float64) float64 {
+	return math.Asinh(x)
+}
+
+// Atan returns the arctangent, in radians, of x.
+//
+// Special cases are:
+//      Atan(±0) = ±0
+//      Atan(±Inf) = ±Pi/2
+func Atan(x float64) float64 {
+	return math.Atan(x)
+}
+
+// Atan2 returns the arc tangent of y/x, using
+// the signs of the two to determine the quadrant
+// of the return value.
+//
+// Special cases are (in order):
+//	Atan2(y, NaN) = NaN
+//	Atan2(NaN, x) = NaN
+//	Atan2(+0, x>=0) = +0
+//	Atan2(-0, x>=0) = -0
+//	Atan2(+0, x<=-0) = +Pi
+//	Atan2(-0, x<=-0) = -Pi
+//	Atan2(y>0, 0) = +Pi/2
+//	Atan2(y<0, 0) = -Pi/2
+//	Atan2(+Inf, +Inf) = +Pi/4
+//	Atan2(-Inf, +Inf) = -Pi/4
+//	Atan2(+Inf, -Inf) = 3Pi/4
+//	Atan2(-Inf, -Inf) = -3Pi/4
+//	Atan2(y, +Inf) = 0
+//	Atan2(y>0, -Inf) = +Pi
+//	Atan2(y<0, -Inf) = -Pi
+//	Atan2(+Inf, x) = +Pi/2
+//	Atan2(-Inf, x) = -Pi/2
+func Atan2(y, x float64) float64 {
+	return math.Atan2(y, x)
+}
+
+// Atanh returns the inverse hyperbolic tangent of x.
+//
+// Special cases are:
+//	Atanh(1) = +Inf
+//	Atanh(±0) = ±0
+//	Atanh(-1) = -Inf
+//	Atanh(x) = NaN if x < -1 or x > 1
+//	Atanh(NaN) = NaN
+func Atanh(x float64) float64 {
+	return math.Atanh(x)
+}
+
+// Cbrt returns the cube root of x.
+//
+// Special cases are:
+//	Cbrt(±0) = ±0
+//	Cbrt(±Inf) = ±Inf
+//	Cbrt(NaN) = NaN
+func Cbrt(x float64) float64 {
+	return math.Cbrt(x)
+}
+
+// Mathematical constants.
+const (
+	E   = 2.71828182845904523536028747135266249775724709369995957496696763 // https://oeis.org/A001113
+	Pi  = 3.14159265358979323846264338327950288419716939937510582097494459 // https://oeis.org/A000796
+	Phi = 1.61803398874989484820458683436563811772030917980576286213544862 // https://oeis.org/A001622
+
+	Sqrt2   = 1.41421356237309504880168872420969807856967187537694807317667974 // https://oeis.org/A002193
+	SqrtE   = 1.64872127070012814684865078781416357165377610071014801157507931 // https://oeis.org/A019774
+	SqrtPi  = 1.77245385090551602729816748334114518279754945612238712821380779 // https://oeis.org/A002161
+	SqrtPhi = 1.27201964951406896425242246173749149171560804184009624861664038 // https://oeis.org/A139339
+
+	Ln2    = 0.693147180559945309417232121458176568075500134360255254120680009 // https://oeis.org/A002162
+	Log2E  = 1000000000000000000000000000000000000000000000000000000000000000 / 693147180559945309417232121458176568075500134360255254120680009
+	Ln10   = 2.30258509299404568401799145468436420760110148862877297603332790 // https://oeis.org/A002392
+	Log10E = 10000000000000000000000000000000000000000000000000000000000000 / 23025850929940456840179914546843642076011014886287729760333279
+)
+
+// Copysign returns a value with the magnitude
+// of x and the sign of y.
+func Copysign(x, y float64) float64 {
+	return math.Copysign(x, y)
+}
+
+// Dim returns the maximum of x-y or 0.
+//
+// Special cases are:
+//	Dim(+Inf, +Inf) = NaN
+//	Dim(-Inf, -Inf) = NaN
+//	Dim(x, NaN) = Dim(NaN, x) = NaN
+func Dim(x, y float64) float64 {
+	return math.Dim(x, y)
+}
+
+// Erf returns the error function of x.
+//
+// Special cases are:
+//	Erf(+Inf) = 1
+//	Erf(-Inf) = -1
+//	Erf(NaN) = NaN
+func Erf(x float64) float64 {
+	return math.Erf(x)
+}
+
+// Erfc returns the complementary error function of x.
+//
+// Special cases are:
+//	Erfc(+Inf) = 0
+//	Erfc(-Inf) = 2
+//	Erfc(NaN) = NaN
+func Erfc(x float64) float64 {
+	return math.Erfc(x)
+}
+
+// Erfinv returns the inverse error function of x.
+//
+// Special cases are:
+//	Erfinv(1) = +Inf
+//	Erfinv(-1) = -Inf
+//	Erfinv(x) = NaN if x < -1 or x > 1
+//	Erfinv(NaN) = NaN
+func Erfinv(x float64) float64 {
+	return math.Erfinv(x)
+}
+
+// Erfcinv returns the inverse of Erfc(x).
+//
+// Special cases are:
+//	Erfcinv(0) = +Inf
+//	Erfcinv(2) = -Inf
+//	Erfcinv(x) = NaN if x < 0 or x > 2
+//	Erfcinv(NaN) = NaN
+func Erfcinv(x float64) float64 {
+	return math.Erfcinv(x)
+}
+
+// Exp returns e**x, the base-e exponential of x.
+//
+// Special cases are:
+//	Exp(+Inf) = +Inf
+//	Exp(NaN) = NaN
+// Very large values overflow to 0 or +Inf.
+// Very small values underflow to 1.
+func Exp(x float64) float64 {
+	return math.Exp(x)
+}
+
+// Exp2 returns 2**x, the base-2 exponential of x.
+//
+// Special cases are the same as Exp.
+func Exp2(x float64) float64 {
+	return math.Exp2(x)
+}
+
+// Expm1 returns e**x - 1, the base-e exponential of x minus 1.
+// It is more accurate than Exp(x) - 1 when x is near zero.
+//
+// Special cases are:
+//	Expm1(+Inf) = +Inf
+//	Expm1(-Inf) = -1
+//	Expm1(NaN) = NaN
+// Very large values overflow to -1 or +Inf.
+func Expm1(x float64) float64 {
+	return math.Expm1(x)
+}
+
+// Gamma returns the Gamma function of x.
+//
+// Special cases are:
+//	Gamma(+Inf) = +Inf
+//	Gamma(+0) = +Inf
+//	Gamma(-0) = -Inf
+//	Gamma(x) = NaN for integer x < 0
+//	Gamma(-Inf) = NaN
+//	Gamma(NaN) = NaN
+func Gamma(x float64) float64 {
+	return math.Gamma(x)
+}
+
+// Hypot returns Sqrt(p*p + q*q), taking care to avoid
+// unnecessary overflow and underflow.
+//
+// Special cases are:
+//	Hypot(±Inf, q) = +Inf
+//	Hypot(p, ±Inf) = +Inf
+//	Hypot(NaN, q) = NaN
+//	Hypot(p, NaN) = NaN
+func Hypot(p, q float64) float64 {
+	return math.Hypot(p, q)
+}
+
+// J0 returns the order-zero Bessel function of the first kind.
+//
+// Special cases are:
+//	J0(±Inf) = 0
+//	J0(0) = 1
+//	J0(NaN) = NaN
+func J0(x float64) float64 {
+	return math.J0(x)
+}
+
+// Y0 returns the order-zero Bessel function of the second kind.
+//
+// Special cases are:
+//	Y0(+Inf) = 0
+//	Y0(0) = -Inf
+//	Y0(x < 0) = NaN
+//	Y0(NaN) = NaN
+func Y0(x float64) float64 {
+	return math.Y0(x)
+}
+
+// J1 returns the order-one Bessel function of the first kind.
+//
+// Special cases are:
+//	J1(±Inf) = 0
+//	J1(NaN) = NaN
+func J1(x float64) float64 {
+	return math.J1(x)
+}
+
+// Y1 returns the order-one Bessel function of the second kind.
+//
+// Special cases are:
+//	Y1(+Inf) = 0
+//	Y1(0) = -Inf
+//	Y1(x < 0) = NaN
+//	Y1(NaN) = NaN
+func Y1(x float64) float64 {
+	return math.Y1(x)
+}
+
+// Jn returns the order-n Bessel function of the first kind.
+//
+// Special cases are:
+//	Jn(n, ±Inf) = 0
+//	Jn(n, NaN) = NaN
+func Jn(n int, x float64) float64 {
+	return math.Jn(n, x)
+}
+
+// Yn returns the order-n Bessel function of the second kind.
+//
+// Special cases are:
+//	Yn(n, +Inf) = 0
+//	Yn(n ≥ 0, 0) = -Inf
+//	Yn(n < 0, 0) = +Inf if n is odd, -Inf if n is even
+//	Yn(n, x < 0) = NaN
+//	Yn(n, NaN) = NaN
+func Yn(n int, x float64) float64 {
+	return math.Yn(n, x)
+}
+
+// Ldexp is the inverse of Frexp.
+// It returns frac × 2**exp.
+//
+// Special cases are:
+//	Ldexp(±0, exp) = ±0
+//	Ldexp(±Inf, exp) = ±Inf
+//	Ldexp(NaN, exp) = NaN
+func Ldexp(frac float64, exp int) float64 {
+	return math.Ldexp(frac, exp)
+}
+
+// Log returns the natural logarithm of x.
+//
+// Special cases are:
+//	Log(+Inf) = +Inf
+//	Log(0) = -Inf
+//	Log(x < 0) = NaN
+//	Log(NaN) = NaN
+func Log(x float64) float64 {
+	return math.Log(x)
+}
+
+// Log10 returns the decimal logarithm of x.
+// The special cases are the same as for Log.
+func Log10(x float64) float64 {
+	return math.Log10(x)
+}
+
+// Log2 returns the binary logarithm of x.
+// The special cases are the same as for Log.
+func Log2(x float64) float64 {
+	return math.Log2(x)
+}
+
+// Log1p returns the natural logarithm of 1 plus its argument x.
+// It is more accurate than Log(1 + x) when x is near zero.
+//
+// Special cases are:
+//	Log1p(+Inf) = +Inf
+//	Log1p(±0) = ±0
+//	Log1p(-1) = -Inf
+//	Log1p(x < -1) = NaN
+//	Log1p(NaN) = NaN
+func Log1p(x float64) float64 {
+	return math.Log1p(x)
+}
+
+// Logb returns the binary exponent of x.
+//
+// Special cases are:
+//	Logb(±Inf) = +Inf
+//	Logb(0) = -Inf
+//	Logb(NaN) = NaN
+func Logb(x float64) float64 {
+	return math.Logb(x)
+}
+
+// Ilogb returns the binary exponent of x as an integer.
+//
+// Special cases are:
+//	Ilogb(±Inf) = MaxInt32
+//	Ilogb(0) = MinInt32
+//	Ilogb(NaN) = MaxInt32
+func Ilogb(x float64) int {
+	return math.Ilogb(x)
+}
+
+// Mod returns the floating-point remainder of x/y.
+// The magnitude of the result is less than y and its
+// sign agrees with that of x.
+//
+// Special cases are:
+//	Mod(±Inf, y) = NaN
+//	Mod(NaN, y) = NaN
+//	Mod(x, 0) = NaN
+//	Mod(x, ±Inf) = x
+//	Mod(x, NaN) = NaN
+func Mod(x, y float64) float64 {
+	return math.Mod(x, y)
+}
+
+// Pow returns x**y, the base-x exponential of y.
+//
+// Special cases are (in order):
+//	Pow(x, ±0) = 1 for any x
+//	Pow(1, y) = 1 for any y
+//	Pow(x, 1) = x for any x
+//	Pow(NaN, y) = NaN
+//	Pow(x, NaN) = NaN
+//	Pow(±0, y) = ±Inf for y an odd integer < 0
+//	Pow(±0, -Inf) = +Inf
+//	Pow(±0, +Inf) = +0
+//	Pow(±0, y) = +Inf for finite y < 0 and not an odd integer
+//	Pow(±0, y) = ±0 for y an odd integer > 0
+//	Pow(±0, y) = +0 for finite y > 0 and not an odd integer
+//	Pow(-1, ±Inf) = 1
+//	Pow(x, +Inf) = +Inf for |x| > 1
+//	Pow(x, -Inf) = +0 for |x| > 1
+//	Pow(x, +Inf) = +0 for |x| < 1
+//	Pow(x, -Inf) = +Inf for |x| < 1
+//	Pow(+Inf, y) = +Inf for y > 0
+//	Pow(+Inf, y) = +0 for y < 0
+//	Pow(-Inf, y) = Pow(-0, -y)
+//	Pow(x, y) = NaN for finite x < 0 and finite non-integer y
+func Pow(x, y float64) float64 {
+	return math.Pow(x, y)
+}
+
+// Pow10 returns 10**n, the base-10 exponential of n.
+//
+// Special cases are:
+//	Pow10(n) =    0 for n < -323
+//	Pow10(n) = +Inf for n > 308
+func Pow10(n int) float64 {
+	return math.Pow10(n)
+}
+
+// Remainder returns the IEEE 754 floating-point remainder of x/y.
+//
+// Special cases are:
+//	Remainder(±Inf, y) = NaN
+//	Remainder(NaN, y) = NaN
+//	Remainder(x, 0) = NaN
+//	Remainder(x, ±Inf) = x
+//	Remainder(x, NaN) = NaN
+func Remainder(x, y float64) float64 {
+	return math.Remainder(x, y)
+}
+
+// Signbit returns true if x is negative or negative zero.
+func Signbit(x float64) bool {
+	return math.Signbit(x)
+}
+
+// Cos returns the cosine of the radian argument x.
+//
+// Special cases are:
+//	Cos(±Inf) = NaN
+//	Cos(NaN) = NaN
+func Cos(x float64) float64 {
+	return math.Cos(x)
+}
+
+// Sin returns the sine of the radian argument x.
+//
+// Special cases are:
+//	Sin(±0) = ±0
+//	Sin(±Inf) = NaN
+//	Sin(NaN) = NaN
+func Sin(x float64) float64 {
+	return math.Sin(x)
+}
+
+// Sinh returns the hyperbolic sine of x.
+//
+// Special cases are:
+//	Sinh(±0) = ±0
+//	Sinh(±Inf) = ±Inf
+//	Sinh(NaN) = NaN
+func Sinh(x float64) float64 {
+	return math.Sinh(x)
+}
+
+// Cosh returns the hyperbolic cosine of x.
+//
+// Special cases are:
+//	Cosh(±0) = 1
+//	Cosh(±Inf) = +Inf
+//	Cosh(NaN) = NaN
+func Cosh(x float64) float64 {
+	return math.Cosh(x)
+}
+
+// Sqrt returns the square root of x.
+//
+// Special cases are:
+//	Sqrt(+Inf) = +Inf
+//	Sqrt(±0) = ±0
+//	Sqrt(x < 0) = NaN
+//	Sqrt(NaN) = NaN
+func Sqrt(x float64) float64 {
+	return math.Sqrt(x)
+}
+
+// Tan returns the tangent of the radian argument x.
+//
+// Special cases are:
+//	Tan(±0) = ±0
+//	Tan(±Inf) = NaN
+//	Tan(NaN) = NaN
+func Tan(x float64) float64 {
+	return math.Tan(x)
+}
+
+// Tanh returns the hyperbolic tangent of x.
+//
+// Special cases are:
+//	Tanh(±0) = ±0
+//	Tanh(±Inf) = ±1
+//	Tanh(NaN) = NaN
+func Tanh(x float64) float64 {
+	return math.Tanh(x)
+}
diff --git a/pkg/path/path.go b/pkg/path/path.go
new file mode 100644
index 0000000..fecc049
--- /dev/null
+++ b/pkg/path/path.go
@@ -0,0 +1,104 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Split,Join extract path
+
+package path
+
+import "path"
+
+// Match reports whether name matches the shell pattern.
+// The pattern syntax is:
+//
+//	pattern:
+//		{ term }
+//	term:
+//		'*'         matches any sequence of non-/ characters
+//		'?'         matches any single non-/ character
+//		'[' [ '^' ] { character-range } ']'
+//		            character class (must be non-empty)
+//		c           matches character c (c != '*', '?', '\\', '[')
+//		'\\' c      matches character c
+//
+//	character-range:
+//		c           matches character c (c != '\\', '-', ']')
+//		'\\' c      matches character c
+//		lo '-' hi   matches character c for lo <= c <= hi
+//
+// Match requires pattern to match all of name, not just a substring.
+// The only possible returned error is ErrBadPattern, when pattern
+// is malformed.
+//
+func Match(pattern, name string) (matched bool, err error) {
+	return path.Match(pattern, name)
+}
+
+// Clean returns the shortest path name equivalent to path
+// by purely lexical processing. It applies the following rules
+// iteratively until no further processing can be done:
+//
+//	1. Replace multiple slashes with a single slash.
+//	2. Eliminate each . path name element (the current directory).
+//	3. Eliminate each inner .. path name element (the parent directory)
+//	   along with the non-.. element that precedes it.
+//	4. Eliminate .. elements that begin a rooted path:
+//	   that is, replace "/.." by "/" at the beginning of a path.
+//
+// The returned path ends in a slash only if it is the root "/".
+//
+// If the result of this process is an empty string, Clean
+// returns the string ".".
+//
+// See also Rob Pike, ``Lexical File Names in Plan 9 or
+// Getting Dot-Dot Right,''
+// https://9p.io/sys/doc/lexnames.html
+func Clean(path string) string { return pathClean(path) }
+
+var pathClean = path.Clean
+
+// Ext returns the file name extension used by path.
+// The extension is the suffix beginning at the final dot
+// in the final slash-separated element of path;
+// it is empty if there is no dot.
+func Ext(path string) string { return pathExt(path) }
+
+var pathExt = path.Ext
+
+// Base returns the last element of path.
+// Trailing slashes are removed before extracting the last element.
+// If the path is empty, Base returns ".".
+// If the path consists entirely of slashes, Base returns "/".
+func Base(path string) string { return pathBase(path) }
+
+var pathBase = path.Base
+
+// IsAbs reports whether the path is absolute.
+func IsAbs(path string) bool { return pathIsAbs(path) }
+
+var pathIsAbs = path.IsAbs
+
+// Dir returns all but the last element of path, typically the path's directory.
+// After dropping the final element using Split, the path is Cleaned and trailing
+// slashes are removed.
+// If the path is empty, Dir returns ".".
+// If the path consists entirely of slashes followed by non-slash bytes, Dir
+// returns a single slash. In any other case, the returned path does not end in a
+// slash.
+func Dir(path string) string { return pathDir(path) }
+
+var pathDir = path.Dir
diff --git a/pkg/regexp/regexp.go b/pkg/regexp/regexp.go
new file mode 100644
index 0000000..fe34a5d
--- /dev/null
+++ b/pkg/regexp/regexp.go
@@ -0,0 +1,37 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Compile,Append,Reader,Match$ -stripstr extract regexp
+
+package regexp
+
+import "regexp"
+
+// Match reports whether the string s
+// contains any match of the regular expression pattern.
+// More complicated queries need to use Compile and the full Regexp interface.
+func Match(pattern string, s string) (matched bool, err error) {
+	return regexp.MatchString(pattern, s)
+}
+
+// QuoteMeta returns a string that escapes all regular expression metacharacters
+// inside the argument text; the returned string is a regular expression matching
+// the literal text.
+func QuoteMeta(s string) string {
+	return regexp.QuoteMeta(s)
+}
diff --git a/pkg/strconv/strconv.go b/pkg/strconv/strconv.go
new file mode 100644
index 0000000..ecd73d5
--- /dev/null
+++ b/pkg/strconv/strconv.go
@@ -0,0 +1,196 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Append,Unquote,Itoa extract strconv
+
+package strconv
+
+import "strconv"
+
+// ParseBool returns the boolean value represented by the string.
+// It accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE, false, False.
+// Any other value returns an error.
+func ParseBool(str string) (bool, error) {
+	return strconv.ParseBool(str)
+}
+
+// FormatBool returns "true" or "false" according to the value of b.
+func FormatBool(b bool) string {
+	return strconv.FormatBool(b)
+}
+
+// ParseFloat converts the string s to a floating-point number
+// with the precision specified by bitSize: 32 for float32, or 64 for float64.
+// When bitSize=32, the result still has type float64, but it will be
+// convertible to float32 without changing its value.
+//
+// If s is well-formed and near a valid floating point number,
+// ParseFloat returns the nearest floating point number rounded
+// using IEEE754 unbiased rounding.
+//
+// The errors that ParseFloat returns have concrete type *NumError
+// and include err.Num = s.
+//
+// If s is not syntactically well-formed, ParseFloat returns err.Err = ErrSyntax.
+//
+// If s is syntactically well-formed but is more than 1/2 ULP
+// away from the largest floating point number of the given size,
+// ParseFloat returns f = ±Inf, err.Err = ErrRange.
+func ParseFloat(s string, bitSize int) (float64, error) {
+	return strconv.ParseFloat(s, bitSize)
+}
+
+// IntSize is the size in bits of an int or uint value.
+const IntSize = 64
+
+// ParseUint is like ParseInt but for unsigned numbers.
+func ParseUint(s string, base int, bitSize int) (uint64, error) {
+	return strconv.ParseUint(s, base, bitSize)
+}
+
+// ParseInt interprets a string s in the given base (0, 2 to 36) and
+// bit size (0 to 64) and returns the corresponding value i.
+//
+// If base == 0, the base is implied by the string's prefix:
+// base 16 for "0x", base 8 for "0", and base 10 otherwise.
+// For bases 1, below 0 or above 36 an error is returned.
+//
+// The bitSize argument specifies the integer type
+// that the result must fit into. Bit sizes 0, 8, 16, 32, and 64
+// correspond to int, int8, int16, int32, and int64.
+// For a bitSize below 0 or above 64 an error is returned.
+//
+// The errors that ParseInt returns have concrete type *NumError
+// and include err.Num = s. If s is empty or contains invalid
+// digits, err.Err = ErrSyntax and the returned value is 0;
+// if the value corresponding to s cannot be represented by a
+// signed integer of the given size, err.Err = ErrRange and the
+// returned value is the maximum magnitude integer of the
+// appropriate bitSize and sign.
+func ParseInt(s string, base int, bitSize int) (i int64, err error) {
+	return strconv.ParseInt(s, base, bitSize)
+}
+
+// Atoi returns the result of ParseInt(s, 10, 0) converted to type int.
+func Atoi(s string) (int, error) {
+	return strconv.Atoi(s)
+}
+
+// FormatFloat converts the floating-point number f to a string,
+// according to the format fmt and precision prec. It rounds the
+// result assuming that the original was obtained from a floating-point
+// value of bitSize bits (32 for float32, 64 for float64).
+//
+// The format fmt is one of
+// 'b' (-ddddp±ddd, a binary exponent),
+// 'e' (-d.dddde±dd, a decimal exponent),
+// 'E' (-d.ddddE±dd, a decimal exponent),
+// 'f' (-ddd.dddd, no exponent),
+// 'g' ('e' for large exponents, 'f' otherwise), or
+// 'G' ('E' for large exponents, 'f' otherwise).
+//
+// The precision prec controls the number of digits (excluding the exponent)
+// printed by the 'e', 'E', 'f', 'g', and 'G' formats.
+// For 'e', 'E', and 'f' it is the number of digits after the decimal point.
+// For 'g' and 'G' it is the maximum number of significant digits (trailing
+// zeros are removed).
+// The special precision -1 uses the smallest number of digits
+// necessary such that ParseFloat will return f exactly.
+func FormatFloat(f float64, fmt byte, prec, bitSize int) string {
+	return strconv.FormatFloat(f, fmt, prec, bitSize)
+}
+
+// FormatUint returns the string representation of i in the given base,
+// for 2 <= base <= 36. The result uses the lower-case letters 'a' to 'z'
+// for digit values >= 10.
+func FormatUint(i uint64, base int) string {
+	return strconv.FormatUint(i, base)
+}
+
+// FormatInt returns the string representation of i in the given base,
+// for 2 <= base <= 36. The result uses the lower-case letters 'a' to 'z'
+// for digit values >= 10.
+func FormatInt(i int64, base int) string {
+	return strconv.FormatInt(i, base)
+}
+
+// Quote returns a double-quoted Go string literal representing s. The
+// returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
+// control characters and non-printable characters as defined by
+// IsPrint.
+func Quote(s string) string {
+	return strconv.Quote(s)
+}
+
+// QuoteToASCII returns a double-quoted Go string literal representing s.
+// The returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
+// non-ASCII characters and non-printable characters as defined by IsPrint.
+func QuoteToASCII(s string) string {
+	return strconv.QuoteToASCII(s)
+}
+
+// QuoteToGraphic returns a double-quoted Go string literal representing s.
+// The returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
+// non-ASCII characters and non-printable characters as defined by IsGraphic.
+func QuoteToGraphic(s string) string {
+	return strconv.QuoteToGraphic(s)
+}
+
+// QuoteRune returns a single-quoted Go character literal representing the
+// rune. The returned string uses Go escape sequences (\t, \n, \xFF, \u0100)
+// for control characters and non-printable characters as defined by IsPrint.
+func QuoteRune(r rune) string {
+	return strconv.QuoteRune(r)
+}
+
+// QuoteRuneToASCII returns a single-quoted Go character literal representing
+// the rune. The returned string uses Go escape sequences (\t, \n, \xFF,
+// \u0100) for non-ASCII characters and non-printable characters as defined
+// by IsPrint.
+func QuoteRuneToASCII(r rune) string {
+	return strconv.QuoteRuneToASCII(r)
+}
+
+// QuoteRuneToGraphic returns a single-quoted Go character literal representing
+// the rune. The returned string uses Go escape sequences (\t, \n, \xFF,
+// \u0100) for non-ASCII characters and non-printable characters as defined
+// by IsGraphic.
+func QuoteRuneToGraphic(r rune) string {
+	return strconv.QuoteRuneToGraphic(r)
+}
+
+// CanBackquote reports whether the string s can be represented
+// unchanged as a single-line backquoted string without control
+// characters other than tab.
+func CanBackquote(s string) bool {
+	return strconv.CanBackquote(s)
+}
+
+// IsPrint reports whether the rune is defined as printable by Go, with
+// the same definition as unicode.IsPrint: letters, numbers, punctuation,
+// symbols and ASCII space.
+func IsPrint(r rune) bool {
+	return strconv.IsPrint(r)
+}
+
+// IsGraphic reports whether the rune is defined as a Graphic by Unicode. Such
+// characters include letters, marks, numbers, punctuation, symbols, and
+// spaces, from categories L, M, N, P, S, and Zs.
+func IsGraphic(r rune) bool {
+	return strconv.IsGraphic(r)
+}
diff --git a/pkg/strings/strings.go b/pkg/strings/strings.go
new file mode 100644
index 0000000..45c7b20
--- /dev/null
+++ b/pkg/strings/strings.go
@@ -0,0 +1,219 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Rune$,Func$,^Map$,Special$,EqualFold,Byte,Title$ extract strings
+
+package strings
+
+import "strings"
+
+// Compare returns an integer comparing two strings lexicographically.
+// The result will be 0 if a==b, -1 if a < b, and +1 if a > b.
+//
+// Compare is included only for symmetry with package bytes.
+// It is usually clearer and always faster to use the built-in
+// string comparison operators ==, <, >, and so on.
+func Compare(a, b string) int {
+	return strings.Compare(a, b)
+}
+
+// Count counts the number of non-overlapping instances of substr in s.
+// If substr is an empty string, Count returns 1 + the number of Unicode code points in s.
+func Count(s, substr string) int {
+	return strings.Count(s, substr)
+}
+
+// Contains reports whether substr is within s.
+func Contains(s, substr string) bool {
+	return strings.Contains(s, substr)
+}
+
+// ContainsAny reports whether any Unicode code points in chars are within s.
+func ContainsAny(s, chars string) bool {
+	return strings.ContainsAny(s, chars)
+}
+
+// LastIndex returns the index of the last instance of substr in s, or -1 if substr is not present in s.
+func LastIndex(s, substr string) int {
+	return strings.LastIndex(s, substr)
+}
+
+// IndexAny returns the index of the first instance of any Unicode code point
+// from chars in s, or -1 if no Unicode code point from chars is present in s.
+func IndexAny(s, chars string) int {
+	return strings.IndexAny(s, chars)
+}
+
+// LastIndexAny returns the index of the last instance of any Unicode code
+// point from chars in s, or -1 if no Unicode code point from chars is
+// present in s.
+func LastIndexAny(s, chars string) int {
+	return strings.LastIndexAny(s, chars)
+}
+
+// SplitN slices s into substrings separated by sep and returns a slice of
+// the substrings between those separators.
+//
+// The count determines the number of substrings to return:
+//   n > 0: at most n substrings; the last substring will be the unsplit remainder.
+//   n == 0: the result is nil (zero substrings)
+//   n < 0: all substrings
+//
+// Edge cases for s and sep (for example, empty strings) are handled
+// as described in the documentation for Split.
+func SplitN(s, sep string, n int) []string {
+	return strings.SplitN(s, sep, n)
+}
+
+// SplitAfterN slices s into substrings after each instance of sep and
+// returns a slice of those substrings.
+//
+// The count determines the number of substrings to return:
+//   n > 0: at most n substrings; the last substring will be the unsplit remainder.
+//   n == 0: the result is nil (zero substrings)
+//   n < 0: all substrings
+//
+// Edge cases for s and sep (for example, empty strings) are handled
+// as described in the documentation for SplitAfter.
+func SplitAfterN(s, sep string, n int) []string {
+	return strings.SplitAfterN(s, sep, n)
+}
+
+// Split slices s into all substrings separated by sep and returns a slice of
+// the substrings between those separators.
+//
+// If s does not contain sep and sep is not empty, Split returns a
+// slice of length 1 whose only element is s.
+//
+// If sep is empty, Split splits after each UTF-8 sequence. If both s
+// and sep are empty, Split returns an empty slice.
+//
+// It is equivalent to SplitN with a count of -1.
+func Split(s, sep string) []string {
+	return strings.Split(s, sep)
+}
+
+// SplitAfter slices s into all substrings after each instance of sep and
+// returns a slice of those substrings.
+//
+// If s does not contain sep and sep is not empty, SplitAfter returns
+// a slice of length 1 whose only element is s.
+//
+// If sep is empty, SplitAfter splits after each UTF-8 sequence. If
+// both s and sep are empty, SplitAfter returns an empty slice.
+//
+// It is equivalent to SplitAfterN with a count of -1.
+func SplitAfter(s, sep string) []string {
+	return strings.SplitAfter(s, sep)
+}
+
+// Fields splits the string s around each instance of one or more consecutive white space
+// characters, as defined by unicode.IsSpace, returning a slice of substrings of s or an
+// empty slice if s contains only white space.
+func Fields(s string) []string {
+	return strings.Fields(s)
+}
+
+// Join concatenates the elements of a to create a single string. The separator string
+// sep is placed between elements in the resulting string.
+func Join(a []string, sep string) string {
+	return strings.Join(a, sep)
+}
+
+// HasPrefix tests whether the string s begins with prefix.
+func HasPrefix(s, prefix string) bool {
+	return strings.HasPrefix(s, prefix)
+}
+
+// HasSuffix tests whether the string s ends with suffix.
+func HasSuffix(s, suffix string) bool {
+	return strings.HasSuffix(s, suffix)
+}
+
+// Repeat returns a new string consisting of count copies of the string s.
+//
+// It panics if count is negative or if
+// the result of (len(s) * count) overflows.
+func Repeat(s string, count int) string {
+	return strings.Repeat(s, count)
+}
+
+// ToUpper returns a copy of the string s with all Unicode letters mapped to their upper case.
+func ToUpper(s string) string {
+	return strings.ToUpper(s)
+}
+
+// ToLower returns a copy of the string s with all Unicode letters mapped to their lower case.
+func ToLower(s string) string {
+	return strings.ToLower(s)
+}
+
+// Trim returns a slice of the string s with all leading and
+// trailing Unicode code points contained in cutset removed.
+func Trim(s string, cutset string) string {
+	return strings.Trim(s, cutset)
+}
+
+// TrimLeft returns a slice of the string s with all leading
+// Unicode code points contained in cutset removed.
+//
+// To remove a prefix, use TrimPrefix instead.
+func TrimLeft(s string, cutset string) string {
+	return strings.TrimLeft(s, cutset)
+}
+
+// TrimRight returns a slice of the string s, with all trailing
+// Unicode code points contained in cutset removed.
+//
+// To remove a suffix, use TrimSuffix instead.
+func TrimRight(s string, cutset string) string {
+	return strings.TrimRight(s, cutset)
+}
+
+// TrimSpace returns a slice of the string s, with all leading
+// and trailing white space removed, as defined by Unicode.
+func TrimSpace(s string) string {
+	return strings.TrimSpace(s)
+}
+
+// TrimPrefix returns s without the provided leading prefix string.
+// If s doesn't start with prefix, s is returned unchanged.
+func TrimPrefix(s, prefix string) string {
+	return strings.TrimPrefix(s, prefix)
+}
+
+// TrimSuffix returns s without the provided trailing suffix string.
+// If s doesn't end with suffix, s is returned unchanged.
+func TrimSuffix(s, suffix string) string {
+	return strings.TrimSuffix(s, suffix)
+}
+
+// Replace returns a copy of the string s with the first n
+// non-overlapping instances of old replaced by new.
+// If old is empty, it matches at the beginning of the string
+// and after each UTF-8 sequence, yielding up to k+1 replacements
+// for a k-rune string.
+// If n < 0, there is no limit on the number of replacements.
+func Replace(s, old, new string, n int) string {
+	return strings.Replace(s, old, new, n)
+}
+
+// Index returns the index of the first instance of substr in s, or -1 if substr is not present in s.
+func Index(s, substr string) int {
+	return strings.Index(s, substr)
+}
diff --git a/pkg/text/template/template.go b/pkg/text/template/template.go
new file mode 100644
index 0000000..9e2eab1
--- /dev/null
+++ b/pkg/text/template/template.go
@@ -0,0 +1,33 @@
+// Copyright 2018 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate qgo -exclude=Escaper$,Must,Parse -stripstr extract text/template
+
+package template
+
+import "text/template"
+
+// HTMLEscape returns the escaped HTML equivalent of the plain text data s.
+func HTMLEscape(s string) string {
+	return template.HTMLEscapeString(s)
+}
+
+// JSEscape returns the escaped JavaScript equivalent of the plain text data s.
+func JSEscape(s string) string {
+	return template.JSEscapeString(s)
+}