Skip to content

Commit

Permalink
fixes for deReference
Browse files Browse the repository at this point in the history
  • Loading branch information
Stepan Pyzhov committed Mar 27, 2019
1 parent db2c579 commit f25912c
Show file tree
Hide file tree
Showing 4 changed files with 325 additions and 85 deletions.
199 changes: 196 additions & 3 deletions buffer.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ const (
type function func(*Node) (*Node, error)
type operation func(left *Node, right *Node) (*Node, error)
type rpn []string
type tokens []string

var (
_null = []byte("null")
Expand Down Expand Up @@ -407,13 +408,19 @@ func (b *buffer) numeric() error {
if find&2 == 0 && find&8 == 0 { // exp part of numeric MUST contains only digits
find &= 2
} else {
return errorSymbol(b)
if find&4 == 0 {
return errorSymbol(b)
}
return nil
}
case c == '+' || c == '-':
if find == 0 || find == 8 {
find |= 1
} else {
return errorSymbol(b)
if find&4 == 0 {
return errorSymbol(b)
}
return nil
}
case c == 'e' || c == 'E':
if find&8 == 0 && find&4 != 0 { // exp without base part
Expand Down Expand Up @@ -490,6 +497,7 @@ func (b *buffer) token() (err error) {
var (
c byte
stack = make([]byte, 0)
first = b.index
start int
find bool
)
Expand Down Expand Up @@ -552,13 +560,16 @@ tokenLoop:
if len(stack) != 0 {
return b.errorEOF()
}
if first == b.index {
return b.step()
}
if b.index >= b.length {
return io.EOF
}
return nil
}

// Builder for `Reverse Polish notation`
// Builder for `Reverse Polish notation`
func (b *buffer) rpn() (result rpn, err error) {
var (
c byte
Expand Down Expand Up @@ -730,6 +741,132 @@ func (b *buffer) rpn() (result rpn, err error) {
return
}

func (b *buffer) tokenize() (result tokens, err error) {
var (
c byte
start int
temp string
current string
variable bool
)
for {
c, err = b.first()
if err != nil {
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
if variable || (c != minus && c != plus) {
variable = false
current = string(c)

c, err = b.next()
if err == nil {
temp = current + string(c)
if priority[temp] != 0 {
current = temp
} else {
b.index--
}
} else {
err = nil
}

result = append(result, current)
break
}
fallthrough // for numbers like `-1e6`
case c >= '0' && c <= '9': // numbers
variable = true
start = b.index
err = b.numeric()
if err != nil && err != io.EOF {
return nil, err
}
current = string(b.data[start:b.index])
result = append(result, current)
if err != nil {
err = nil
} else {
b.index--
}
case c == quote: // string
variable = true
start = b.index
err = b.string(quote)
if err != nil {
return nil, b.errorEOF()
}
current = string(b.data[start : b.index+1])
result = append(result, current)
case c == dollar || c == at: // variable : like @.length , $.expensive, etc.
variable = true
start = b.index
err = b.token()
if err != nil {
if err != io.EOF {
return nil, err
}
}
current = string(b.data[start:b.index])
result = append(result, current)
if err != nil {
err = nil
} else {
b.index--
}
case c == parenthesesL: // (
variable = false
current = string(c)
result = append(result, current)
case c == parenthesesR: // )
variable = true
current = string(c)
result = append(result, current)
default: // prefix functions or etc.
start = b.index
variable = true
for ; b.index < b.length; b.index++ {
c = b.data[b.index]
if c == parenthesesL { // function detection, example: sin(...), round(...), etc.
variable = false
break
}
if c < 'A' || c > 'z' {
if !(c >= '0' && c <= '9') && c != '_' { // constants detection, example: true, false, null, PI, e, etc.
break
}
}
}
if start == b.index {
err = b.step()
if err != nil {
err = nil
current = strings.ToLower(string(b.data[start : b.index+1]))
} else {
current = strings.ToLower(string(b.data[start:b.index]))
b.index--
}
} else {
current = strings.ToLower(string(b.data[start:b.index]))
b.index--
}
result = append(result, current)
}
err = b.step()
if err != nil {
break
}
}

if err != io.EOF {
return
}
err = nil

return
}

func (b *buffer) errorEOF() error {
return errorEOF(b)
}
Expand Down Expand Up @@ -827,3 +964,59 @@ func boolean(node *Node) (bool, error) {
}
return false, nil
}

func tokenize(cmd string) (result tokens, err error) {
buf := newBuffer([]byte(cmd))
return buf.tokenize()
}

func (t tokens) exists(find string) bool {
for _, s := range t {
if s == find {
return true
}
}
return false
}

func (t tokens) count(find string) int {
i := 0
for _, s := range t {
if s == find {
i++
}
}
return i
}

func (t tokens) find(find string, from int) int {
n := len(t)
for i := from; i < n; i++ {
if t[i] == find {
return i
}
}
return -1
}

func (t tokens) slice(find string) []string {
n := len(t)
result := make([]string, 0, t.count(find))
from := 0
for i := 0; i < n; i++ {
if t[i] == find {
result = append(result, strings.Join(t[from:i], ""))
from = i + 1
}
}
result = append(result, strings.Join(t[from:n], ""))
return result
}

func str(key string) (string, bool) {
from := len(key)
if from > 1 && key[0] == quote && key[from-1] == quote {
return key[1 : from-1], true
}
return key, false
}
32 changes: 32 additions & 0 deletions buffer_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,8 @@ func TestBuffer_RPN(t *testing.T) {
{name: "example_6", value: "3 + 4 * -2 / (-1 - 5)**-2", expected: []string{"3", "4", "-2", "*", "-1", "5", "-", "-2", "**", "/", "+"}},
{name: "example_7", value: "1.3e2 + sin(2*pi/3)", expected: []string{"1.3e2", "2", "pi", "*", "3", "/", "sin", "+"}},
{name: "example_8", value: "@.length-1", expected: []string{"@.length", "1", "-"}},
{name: "example_9", value: "@.length+-1", expected: []string{"@.length", "-1", "+"}},
{name: "example_10", value: "@.length/e", expected: []string{"@.length", "e", "/"}},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
Expand All @@ -76,3 +78,33 @@ func TestBuffer_RPN(t *testing.T) {
})
}
}

func TestTokenize(t *testing.T) {
tests := []struct {
name string
value string
expected []string
}{
{name: "example_1", value: "@.length", expected: []string{"@.length"}},
{name: "example_2", value: "1 + 2", expected: []string{"1", "+", "2"}},
{name: "example_3", value: "1+2", expected: []string{"1", "+", "2"}},
{name: "example_4", value: "1:", expected: []string{"1", ":"}},
{name: "example_5", value: ":2 :1", expected: []string{":", "2", ":", "1"}},
{name: "example_6", value: "1 ,2,'foo'", expected: []string{"1", ",", "2", ",", "'foo'"}},
{name: "example_7", value: "(@.length-1)", expected: []string{"(", "@.length", "-", "1", ")"}},
{name: "example_8", value: "?(@.length-1)", expected: []string{"?", "(", "@.length", "-", "1", ")"}},
{name: "example_9", value: "'foo'", expected: []string{"'foo'"}},
{name: "example_10", value: "$.foo[(@.length - 3):3:]", expected: []string{"$.foo[(@.length - 3):3:]"}},
{name: "example_11", value: "$..", expected: []string{"$.."}},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
result, err := tokenize(test.value)
if err != nil {
t.Errorf("Unexpected error: %s", err.Error())
} else if !sliceEqual(test.expected, result) {
t.Errorf("Error on RPN(%s): result doesn't match\nExpected: %s\nActual: %s", test.value, sliceString(test.expected), sliceString(result))
}
})
}
}
Loading

0 comments on commit f25912c

Please sign in to comment.