Merge pull request #4 from opethe1st/support-numbers

Support numbers

Author: opethe1st

load.go

@@ -9,6 +9,8 @@ package json
 
 import (
 	"fmt"
+	"math"
+	"strconv"
 	"unicode"
 )
 
@@ -21,14 +23,14 @@ func Load(s string) interface{} {
 func load(iter *iterator) interface{} {
 	consumeWhiteSpace(iter)
 	switch {
-	case iter.isEnd():
-		return nil
 	case iter.getCurrent() == 'n':
 		return loadKeyword(iter, "null", nil)
 	case iter.getCurrent() == 't':
 		return loadKeyword(iter, "true", true)
 	case iter.getCurrent() == 'f':
 		return loadKeyword(iter, "false", false)
+	case isNumber(iter):
+		return loadNumber(iter)
 	case iter.getCurrent() == '"':
 		return loadString(iter)
 	case iter.getCurrent() == '[':
@@ -54,7 +56,74 @@ func loadKeyword(iter *iterator, keyword string, value interface{}) interface{}
 	return value
 }
 
-func loadString(iter *iterator) interface{} {
+func isNumber(iter *iterator) bool {
+	switch iter.getCurrent() {
+	case '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '0':
+		return true
+	}
+	return false
+}
+
+func loadNumber(iter *iterator) interface{} {
+	//negative numbers
+	sign := 1.0
+	if iter.getCurrent() == '-' {
+		sign = -1.0
+		iter.advance()
+	}
+	num := 0.0
+	for !iter.isEnd() && unicode.IsDigit(rune(iter.getCurrent())) {
+		num *= 10
+		val, _ := strconv.ParseInt(string(iter.getCurrent()), 10, 64)
+		num += float64(val)
+		iter.advance()
+	}
+
+	// decimal
+	// some of the code here is a duplicate of what is above, I should consolidate into one function.
+	consume(iter, '.')
+	frac := 0.0
+	power := 0.1
+	for !iter.isEnd() && unicode.IsDigit(rune(iter.getCurrent())) {
+		val, _ := strconv.ParseInt(string(iter.getCurrent()), 10, 64)
+		frac += power * float64(val)
+		power *= 0.1
+		iter.advance()
+	}
+
+	exponent := 0.0
+	//exponent
+	if !iter.isEnd() && ((iter.getCurrent() == 'e') || (iter.getCurrent() == 'E')) {
+		if iter.getCurrent() == 'e' {
+			consume(iter, 'e')
+		}
+		if iter.getCurrent() == 'E' {
+			consume(iter, 'E')
+		}
+		exponentSign := 1.0
+		//TODO(ope) this is subtly wrong since it allows +-123234, I will fix later
+		if !iter.isEnd() && iter.getCurrent() == '+' {
+			consume(iter, '+')
+		}
+		if !iter.isEnd() && iter.getCurrent() == '-' {
+			consume(iter, '-')
+			exponentSign = -1.0
+		}
+		// there needs to be at least one digit after an exponent
+		exponent = 0.0
+		for !iter.isEnd() && unicode.IsDigit(rune(iter.getCurrent())) {
+			exponent *= 10
+			val, _ := strconv.ParseInt(string(iter.getCurrent()), 10, 64)
+			exponent += float64(val)
+			iter.advance()
+		}
+		exponent *= exponentSign
+	}
+	fmt.Println(num, frac, exponent)
+	return (num + frac) * sign * math.Pow(10, exponent)
+}
+
+func loadString(iter *iterator) string {
 	consume(iter, '"')
 	s := make([]rune, 0)
 	mapping := map[rune]rune{
@@ -101,6 +170,7 @@ func loadString(iter *iterator) interface{} {
 				//need to handle the default case and handle u and hex digits
 			case 'u':
 				var ans rune
+				// I should make sure these are valid hex digits btw, but will leave it for error reporting
 				for i := 0; i < 4; i++ {
 					iter.advance() // move past the 'u'
 					fmt.Println(i, ans, string(iter.getCurrent()))
@@ -170,7 +240,7 @@ func consumeWhiteSpace(iter *iterator) {
 
 func consume(iter *iterator, char byte) {
 	// actually should probably raise an error if char isn't consumed
-	if iter.getCurrent() == char {
+	if !iter.isEnd() && iter.getCurrent() == char {
 		iter.advance()
 	}
 }

load_test.go

@@ -1,6 +1,7 @@
 package json
 
 import (
+	"math"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -29,6 +30,7 @@ func TestLoad(t *testing.T) {
 				"k5": true,
 				"k6": false,
 				"k	6": null,
+				"k7": 123456
 			}`, map[string]interface{}{
 				"k1": "v1",
 				"k2": []interface{}{"v2"},
@@ -40,6 +42,7 @@ func TestLoad(t *testing.T) {
 				"k5":   true,
 				"k6":   false,
 				"k\t6": nil,
+				"k7":   123456.0,
 			},
 		},
 	}
@@ -70,6 +73,7 @@ func TestLoadKeyword(t *testing.T) {
 }
 
 func TestLoadString(t *testing.T) {
+	assert := assert.New(t) // redefinition here -- ugly!
 	testCases := []TestCase{
 		{`"Key"`, "Key"},
 		{`"   Key"`, "   Key"},
@@ -84,25 +88,39 @@ func TestLoadString(t *testing.T) {
 	}
 	for _, testcase := range testCases {
 		iter := &iterator{s: testcase.input}
-		if output := loadString(iter); output != testcase.expectedOutput {
-			t.Errorf("Expected loadString(%v) to be %v but got %v", iter, testcase.expectedOutput, output)
-		}
+		output := loadString(iter)
+		assert.Equal(testcase.expectedOutput, output, "Expected loadNumber(%v) to be %v but got %v", iter, testcase.expectedOutput, output)
 
 	}
 
-	testCases = []TestCase{
-		{`"Key"`, 5},
-		{`"   Key"`, 8},
-		{`"Key"   `, 5},
+}
+
+func TestLoadNumber(t *testing.T) {
+	testCases := []TestCase{
+		{`123`, 123.0},
+		{`-123`, -123.0},
+		{`-123.123`, -123.123},
+		{`0.234`, 0.234},
+		{`1.234e2`, 123.4},
+		{`-1.234e2`, -123.4},
+		{`-0.234e2`, -23.4},
 	}
 	for _, testcase := range testCases {
 		iter := &iterator{s: testcase.input}
-		if loadString(iter); iter.offset != testcase.expectedOutput {
-			t.Errorf("Expected loadString(%v) to be %v but got %v", iter, testcase.expectedOutput, iter.offset)
+		output := loadNumber(iter)
+		if !floatEquals(output.(float64), testcase.expectedOutput.(float64)) {
+			t.Errorf("Expected loadNumber(%v) to be %v but got %v", iter, testcase.expectedOutput, output)
 		}
 	}
 }
 
+func floatEquals(a, b float64) bool {
+	if math.Abs(a-b) < 0.00000001 {
+		return true
+	}
+	return false
+}
+
 func TestLoadSequence(t *testing.T) {
 	assert := assert.New(t)
 	testCases := []TestCase{