Update TestSuite, add more functions to String

base/Char/is_digit.kind

@@ -0,0 +1,2 @@
+Char.is_digit(c: Char): Bool
+  Bool.and(U16.gte(c,'0'),U16.lte(c,'9'))

base/String/is_nat.kind

@@ -0,0 +1,10 @@
+String.is_nat(s: String): Bool
+  String.is_nat.aux(s, true)
+
+String.is_nat.aux(s: String, aux: Bool): Bool
+  case s {
+    nil : aux
+    cons: 
+    let is_digit = Bool.and(Char.is_digit(s.head),aux)
+    String.is_nat.aux(s.tail, is_digit)
+  }

base/String/test/all.kind

@@ -1,4 +1,11 @@
 String.test.all: TestSuite
-  TestSuite.many("String", [
-    String.test.to_hex
-  ])
+  TestSuite.many("String", 
+    [ 
+      String.test.to_hex,
+      String.test.is_nat
+    ])
+
+// Show all tests for String
+String.test.show: _
+  log(TestSuite.show(String.test.all, 0))
+  0

base/String/test/is_nat.kind

@@ -0,0 +1,47 @@
+String.test.is_nat: TestSuite
+  TestSuite.many("String.is_number", [
+    String.test.is_nat.0, String.test.is_nat.1, String.test.is_nat.2,
+    String.test.is_nat.3, String.test.is_nat.4, String.test.is_nat.5,
+  ])
+
+String.test.is_nat.0: TestSuite
+  let test = "0123"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.true"
+  let name = "0"
+  TestSuite.show.string(name, test, exp, got)
+
+String.test.is_nat.1: TestSuite
+  let test = "-987"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.false"
+  let name = "1"
+  TestSuite.show.string(name, test, exp, got)
+
+String.test.is_nat.2: TestSuite
+  let test = "0865a"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.false"
+  let name = "2"
+  TestSuite.show.string(name, test, exp, got)
+
+String.test.is_nat.3: TestSuite
+  let test = "9007199254740991n"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.false"
+  let name = "3"
+  TestSuite.show.string(name, test, exp, got)
+
+String.test.is_nat.4: TestSuite
+  let test = "011101011101"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.true"
+  let name = "4"
+  TestSuite.show.string(name, test, exp, got)
+
+String.test.is_nat.5: TestSuite
+  let test = "2.3847623487236483e+24"
+  let got = Bool.show(String.is_nat(test))
+  let exp = "Bool.false"
+  let name = "5"
+  TestSuite.show.string(name, test, exp, got)

base/String/test/to_hex.kind

@@ -13,73 +13,73 @@ String.test.to_hex: TestSuite
 
 String.test.to_hex.0: TestSuite
   let test = "abcdef"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "616263646566"
   let name = "0"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.1: TestSuite
   let test = ""
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = ""
   let name = "1"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.2: TestSuite
   let test = "á"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "c3a1"
   let name = "2"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.3: TestSuite
   let test = "ü"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "c3bc"
   let name = "3"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.4: TestSuite
   let test = "õ"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "c3b5"
   let name = "4"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.5: TestSuite
   let test = "1234567890"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "31323334353637383930"
   let name = "5"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 String.test.to_hex.6: TestSuite
   let test = "{%$@"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "7b252440"
   let name = "6"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 // 2 bytes UTF-8
 String.test.to_hex.7: TestSuite
   let test = "¢"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "c2a2"
   let name = "7"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 // 3 bytes UTF-8
 String.test.to_hex.8: TestSuite
   let test = "ह€"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "e0a4b9e282ac"
   let name = "8"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)
 
 // 4 bytes UTF-8
 String.test.to_hex.9: TestSuite
   let test = "𐍈"
-  let hex = String.to_hex(test)
+  let got = String.to_hex(test)
   let exp = "f0908d88"
   let name = "9"
-  TestSuite.log.string(name, test, exp, hex)
+  TestSuite.show.string(name, test, exp, got)

base/TestSuite/show.kind

@@ -35,7 +35,7 @@ TestSuite.show.check_fail(s: TestSuite): String
 TestSuite.log(name: String, test: String, expected: String, got: String): String
   "\n["|name|"] test: "|test|"\nexpected: "|expected|"\ngot: "|got
 
-TestSuite.log.string(name: String, test: String, expected: String, got: String): TestSuite
+TestSuite.show.string(name: String, test: String, expected: String, got: String): TestSuite
   let res = 
     if String.eql(expected, got) 
     then Maybe.none!