Fixed operation parser (#46)

README.md

@@ -53,7 +53,7 @@ func main() {
 You can download `ajson` cli from the [release page](https://github.com/spyzhov/ajson/releases), or install from the source:
 
 ```shell script
-go get github.com/spyzhov/ajson/cmd/[email protected].0
+go get github.com/spyzhov/ajson/cmd/[email protected].1
 ```
 
 Usage:

buffer.go

@@ -41,15 +41,15 @@ const (
 	asterisk     byte = '*'
 	plus         byte = '+'
 	minus        byte = '-'
-	division     byte = '/'
-	exclamation  byte = '!'
-	caret        byte = '^'
-	signL        byte = '<'
-	signG        byte = '>'
-	signE        byte = '='
-	ampersand    byte = '&'
-	pipe         byte = '|'
-	question     byte = '?'
+	//division     byte = '/'
+	//exclamation  byte = '!'
+	//caret        byte = '^'
+	//signL        byte = '<'
+	//signG        byte = '>'
+	//signE        byte = '='
+	//ampersand    byte = '&'
+	//pipe         byte = '|'
+	question byte = '?'
 )
 
 type (
@@ -88,6 +88,23 @@ func (b *buffer) next() (c byte, err error) {
 	return b.data[b.index], nil
 }
 
+func (b *buffer) slice(delta uint) ([]byte, error) {
+	if b.index+int(delta) > b.length {
+		return nil, io.EOF
+	}
+	return b.data[b.index : b.index+int(delta)], nil
+}
+
+func (b *buffer) move(delta int) error {
+	if b.index+delta >= b.length {
+		return io.EOF
+	}
+	if b.index+delta >= 0 {
+		b.index += delta
+	}
+	return nil
+}
+
 func (b *buffer) reset() {
 	b.last = GO
 }
@@ -352,21 +369,13 @@ func (b *buffer) rpn() (result rpn, err error) {
 			break
 		}
 		switch true {
-		case c == asterisk || c == division || c == minus || c == plus || c == caret || c == ampersand || c == pipe || c == signL || c == signG || c == signE || c == exclamation: // operations
+		case priorityChar[c]: // operations
 			if variable {
 				variable = false
-				current = string(c)
+				current = b.operation()
 
-				c, err = b.next()
-				if err == nil {
-					temp = current + string(c)
-					if priority[temp] != 0 {
-						current = temp
-					} else {
-						b.index--
-					}
-				} else {
-					err = nil
+				if current == "" {
+					return nil, b.errorSymbol()
 				}
 
 				for len(stack) > 0 {
@@ -511,7 +520,6 @@ func (b *buffer) tokenize() (result tokens, err error) {
 	var (
 		c        byte
 		start    int
-		temp     string
 		current  string
 		variable bool
 	)
@@ -525,18 +533,10 @@ func (b *buffer) tokenize() (result tokens, err error) {
 		case priorityChar[c]: // operations
 			if variable || (c != minus && c != plus) {
 				variable = false
-				current = string(c)
+				current = b.operation()
 
-				c, err = b.next()
-				if err == nil {
-					temp = current + string(c)
-					if priority[temp] != 0 {
-						current = temp
-					} else {
-						b.index--
-					}
-				} else {
-					err = nil
+				if current == "" {
+					return nil, b.errorSymbol()
 				}
 
 				result = append(result, current)
@@ -637,6 +637,24 @@ func (b *buffer) tokenize() (result tokens, err error) {
 	return
 }
 
+func (b *buffer) operation() string {
+	current := ""
+
+	// Read the complete operation into the variable `current`: `+`, `!=`, `<=>`
+	// fixme: add additional order for comparison
+
+	for _, operation := range comparisonOperationsOrder() {
+		if bytes, ok := b.slice(uint(len(operation))); ok == nil {
+			if string(bytes) == operation {
+				current = operation
+				_ = b.move(len(operation) - 1) // error can't occupy here because of b.slice result
+				break
+			}
+		}
+	}
+	return current
+}
+
 func (b *buffer) errorEOF() error {
 	return errorEOF(b)
 }

buffer_test.go

@@ -76,6 +76,26 @@ func TestBuffer_Token(t *testing.T) {
 	}
 }
 
+func TestBuffer_RPN_long_operations_name(t *testing.T) {
+	jsonpath := `@.key !@#$%^&* 1`
+	_, err := newBuffer([]byte(jsonpath)).rpn()
+	if err == nil {
+		t.Errorf("Expected error, got nothing")
+		return
+	}
+
+	expected := []string{"@.key", "1", "!@#$%^&*"}
+	AddOperation(`!@#$%^&*`, 3, false, func(left *Node, right *Node) (result *Node, err error) {
+		return NullNode(""), nil
+	})
+	result, err := newBuffer([]byte(jsonpath)).rpn()
+	if err != nil {
+		t.Errorf("Unexpected error: %s", err.Error())
+	} else if !sliceEqual(expected, result) {
+		t.Errorf("Error on RPN(%s): result doesn't match\nExpected: %s\nActual:   %s", jsonpath, sliceString(expected), sliceString(result))
+	}
+}
+
 func TestBuffer_RPN(t *testing.T) {
 	tests := []struct {
 		name     string

cmd/ajson/main.go

@@ -12,7 +12,7 @@ import (
 	"github.com/spyzhov/ajson"
 )
 
-var version = "v0.7.0"
+var version = "v0.7.1"
 
 func usage() {
 	text := ``

math.go

@@ -4,6 +4,7 @@ import (
 	"math"
 	"math/rand"
 	"regexp"
+	"sort"
 	"strings"
 )
 
@@ -479,3 +480,15 @@ func mathFactorial(x uint) uint {
 	}
 	return x * mathFactorial(x-1)
 }
+
+func comparisonOperationsOrder() []string {
+	result := make([]string, 0, len(operations))
+	for operation := range operations {
+		result = append(result, operation)
+	}
+
+	sort.Slice(result, func(i, j int) bool {
+		return len(result[i]) > len(result[j])
+	})
+	return result
+}

math_test.go

@@ -247,15 +247,27 @@ func TestAddConstant(t *testing.T) {
 }
 
 func TestAddOperation(t *testing.T) {
-	name := "new_operation_name"
+	name := "_one_to_rule_them_all_"
 	if _, ok := operations[name]; ok {
 		t.Error("test operation already exists")
+		return
 	}
 	AddOperation(name, 1, true, func(left *Node, right *Node) (result *Node, err error) {
 		return NumericNode("example", 1), nil
 	})
 	if _, ok := operations[name]; !ok {
 		t.Error("test operation was not added")
+		return
+	}
+	result, err := Eval(NullNode(""), `@ _one_to_rule_them_all_ 100500`)
+	if err != nil {
+		t.Errorf("Unexpected error: %s", err.Error())
+		return
+	}
+	if ok, err := result.Eq(NumericNode("", 1)); err != nil {
+		t.Errorf("Unexpected error: %s", err.Error())
+	} else if !ok {
+		t.Errorf("Should be one")
 	}
 }