More (complex) RegExp => RE2 transforming and tests

The unescaping of that which does not need escaping

.test262/Makefile

@@ -45,3 +45,4 @@ try-tmp: tmp
 
 look: .fail
 	cat $<
+	@echo `readlink $<`

.test262/cull

@@ -67,4 +67,7 @@ rm -f ch07/7.6/7.6.1/7.6.1-8-8.js
 rm -f ch07/7.6/7.6.1/7.6.1-8-9.js
 # Skip, no backreferencing in re2
 rm -f ch07/7.8/7.8.5/S7.8.5_A1.4_T1.js
+# We WANT to squawk on \1, \2, \3, ..., \9
+# TODO Come up with replacement test?
+rm -f ch07/7.8/7.8.5/S7.8.5_A1.4_T2.js
 popd

Makefile

@@ -23,10 +23,10 @@ TEST := -v --run String_fromCharCode
 TEST := -v --run Lexer\|Parse
 TEST := -v --run Lexer
 TEST := -v --run String_
-TEST := -v --run RegExp 
 TEST := -v --run ParseSuccess 
 TEST := -v --run Parse
 TEST := -v --run ParseFailure
+TEST := -v --run RegExp 
 TEST := .
 
 test: test-i

otto_test.go

@@ -57,6 +57,7 @@ func TestTransformRegExp(t *testing.T) {
 	Terst(t)
 
 	Is(transformRegExp(`\\|'|\r|\n|\t|\u2028|\u2029`), `\\|'|\r|\n|\t|\x{2028}|\x{2029}`)
+	Is(transformRegExp(`\x`), `x`)
 }
 
 func TestIsValidRegExp(t *testing.T) {
@@ -1567,6 +1568,20 @@ func TestRegExp(t *testing.T) {
 	test(`/\a/.source`, "\\a")
 	test(`/\;/.source`, "\\;")
 	test(`/\ /.source`, "\\ ")
+
+	// Start sanity check...
+	test("eval(\"/abc/\").source", "abc")
+	test("eval(\"/\u0023/\").source", "#")
+	test("eval(\"/\u0058/\").source", "X")
+	test("eval(\"/\\\u0023/\").source == \"\\\u0023\"", "true")
+	test("'0x' + '0058'", "0x0058")
+	test("'\\\\' + '0x' + '0058'", "\\0x0058")
+	// ...stop sanity check
+
+	test(`abc = '\\' + String.fromCharCode('0x' + '0058'); eval('/' + abc + '/').source`, "\\X")
+	test(`abc = '\\' + String.fromCharCode('0x0058'); eval('/' + abc + '/').source == "\\\u0058"`, "true")
+	test(`abc = '\\' + String.fromCharCode('0x0023'); eval('/' + abc + '/').source == "\\\u0023"`, "true")
+	test(`abc = '\\' + String.fromCharCode('0x0078'); eval('/' + abc + '/').source == "\\\u0078"`, "true")
 }
 
 func TestNewFunction(t *testing.T) {

type_regexp.go

@@ -3,6 +3,7 @@ package otto
 import (
 	"fmt"
 	"regexp"
+	"strings"
 )
 
 type _regExpObject struct {
@@ -98,11 +99,75 @@ func execResultToArray(runtime *_runtime, target string, result []int) *_object
 	return runtime.newArray(valueArray)
 }
 
-/*var transformRegExp_matchSlashU *regexp.Regexp = regexp.MustCompile(`\\u([:xdigit:]{1-4})`)*/
+// 0031,0032,0033,0034,0035,0036,0037,0038,0039 // 1 - 9
-var transformRegExp_matchSlashU *regexp.Regexp = regexp.MustCompile(`\\u([[:xdigit:]]{1,4})`)
+// 0043,0045,0046,0047,0048,0049,004A,004B,004C,004D,004E,004F
+// 0050,0052,0054,0055,0056,0058,0059,005A
+// 0063,0065,0067,0068,0069,006A,006B,006C,006D,006F
+// 0070,0071,0075,0078,0079
+// 0080,0081,0082,0083,0084,0085,0086,0087,0088,0089,008A,008B,008C,008D,008E,008F
+// 0090,0091,0092,0093,0094,0095,0096,0097,0098,0099,009A,009B,009C,009D,009E,009F
+// 00A0,00A1,00A2,00A3,00A4,00A5,00A6,00A7,00A8,00A9,00AA,00AB,00AC,00AD,00AE,00AF
+// 00B0,00B1,00B2,00B3,00B4,00B5,00B6,00B7,00B8,00B9,00BA,00BB,00BC,00BD,00BE,00BF
+// 00C0,00C1,00C2,00C3,00C4,00C5,00C6,00C7,00C8,00C9,00CA,00CB,00CC,00CD,00CE,00CF
+// ...
+// c = 63* c[A-Z]
+// p = 70
+// u = 75* u[:xdigit:]{4}
+// x = 78* x[:xdigit:]{2}
+//\x{0031}-\x{0039}
+
+var transformRegExp_matchSlashU = regexp.MustCompile(`\\u([[:xdigit:]]{1,4})`)
+var transformRegExp_unescape = regexp.MustCompile(strings.NewReplacer("\n", "", "\t", "", " ", "").Replace(`
+
+	(?:
+		\\(
+		[
+			\x{0043}\x{0045}-\x{004F}
+			\x{0050}\x{0052}\x{0054}-\x{0056}\x{0058}-\x{005A}
+			\x{0065}\x{0067}-\x{006D}\x{006F}
+			\x{0070}\x{0071}\x{0079}
+			\x{0080}-\x{FFFF}
+		]
+		)()
+	) |
+	(?:
+		\\(c)([^A-Z])
+	) |
+	(?:
+		\\(u)([^[:xdigit:]])
+	) |
+	(?:
+		\\(u)([:xdigit:][^[:xdigit:]])
+	) |
+	(?:
+		\\(u)([:xdigit:][:xdigit:][^[:xdigit:]])
+	) |
+	(?:
+		\\(u)([:xdigit:][:xdigit:][:xdigit:][^[:xdigit:]])
+	) |
+	(?:
+		\\(x)([^[:xdigit:]])
+	) |
+	(?:
+		\\(x)([:xdigit:][^[:xdigit:]])
+	)
+
+`))
+var transformRegExp_unescapeDollar = regexp.MustCompile(strings.NewReplacer("\n", "", "\t", "", " ", "").Replace(`
+
+	(?:
+		\\([cux])$
+	)
+
+`))
+// TODO Go "regexp" bug? Can't do: (?:)|(?:$)
 
 func transformRegExp(ecmaRegExp string) (goRegExp string) {
-	return transformRegExp_matchSlashU.ReplaceAllString(ecmaRegExp, `\x{$1}`)
+	tmp := []byte(ecmaRegExp)
+	tmp = transformRegExp_unescape.ReplaceAll(tmp, []byte(`$1$2`))
+	tmp = transformRegExp_unescapeDollar.ReplaceAll(tmp, []byte(`$1`))
+	tmp = transformRegExp_matchSlashU.ReplaceAll(tmp, []byte(`\x{$1}`))
+	return string(tmp)
 }
 
 func isValidRegExp(ecmaRegExp string) bool {