aboutsummaryrefslogtreecommitdiff
path: root/vendor/github.com/jmespath/go-jmespath/parser.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/jmespath/go-jmespath/parser.go')
-rw-r--r--vendor/github.com/jmespath/go-jmespath/parser.go603
1 files changed, 603 insertions, 0 deletions
diff --git a/vendor/github.com/jmespath/go-jmespath/parser.go b/vendor/github.com/jmespath/go-jmespath/parser.go
new file mode 100644
index 0000000..1240a17
--- /dev/null
+++ b/vendor/github.com/jmespath/go-jmespath/parser.go
@@ -0,0 +1,603 @@
+package jmespath
+
+import (
+ "encoding/json"
+ "fmt"
+ "strconv"
+ "strings"
+)
+
+type astNodeType int
+
+//go:generate stringer -type astNodeType
+const (
+ ASTEmpty astNodeType = iota
+ ASTComparator
+ ASTCurrentNode
+ ASTExpRef
+ ASTFunctionExpression
+ ASTField
+ ASTFilterProjection
+ ASTFlatten
+ ASTIdentity
+ ASTIndex
+ ASTIndexExpression
+ ASTKeyValPair
+ ASTLiteral
+ ASTMultiSelectHash
+ ASTMultiSelectList
+ ASTOrExpression
+ ASTAndExpression
+ ASTNotExpression
+ ASTPipe
+ ASTProjection
+ ASTSubexpression
+ ASTSlice
+ ASTValueProjection
+)
+
+// ASTNode represents the abstract syntax tree of a JMESPath expression.
+type ASTNode struct {
+ nodeType astNodeType
+ value interface{}
+ children []ASTNode
+}
+
+func (node ASTNode) String() string {
+ return node.PrettyPrint(0)
+}
+
+// PrettyPrint will pretty print the parsed AST.
+// The AST is an implementation detail and this pretty print
+// function is provided as a convenience method to help with
+// debugging. You should not rely on its output as the internal
+// structure of the AST may change at any time.
+func (node ASTNode) PrettyPrint(indent int) string {
+ spaces := strings.Repeat(" ", indent)
+ output := fmt.Sprintf("%s%s {\n", spaces, node.nodeType)
+ nextIndent := indent + 2
+ if node.value != nil {
+ if converted, ok := node.value.(fmt.Stringer); ok {
+ // Account for things like comparator nodes
+ // that are enums with a String() method.
+ output += fmt.Sprintf("%svalue: %s\n", strings.Repeat(" ", nextIndent), converted.String())
+ } else {
+ output += fmt.Sprintf("%svalue: %#v\n", strings.Repeat(" ", nextIndent), node.value)
+ }
+ }
+ lastIndex := len(node.children)
+ if lastIndex > 0 {
+ output += fmt.Sprintf("%schildren: {\n", strings.Repeat(" ", nextIndent))
+ childIndent := nextIndent + 2
+ for _, elem := range node.children {
+ output += elem.PrettyPrint(childIndent)
+ }
+ }
+ output += fmt.Sprintf("%s}\n", spaces)
+ return output
+}
+
+var bindingPowers = map[tokType]int{
+ tEOF: 0,
+ tUnquotedIdentifier: 0,
+ tQuotedIdentifier: 0,
+ tRbracket: 0,
+ tRparen: 0,
+ tComma: 0,
+ tRbrace: 0,
+ tNumber: 0,
+ tCurrent: 0,
+ tExpref: 0,
+ tColon: 0,
+ tPipe: 1,
+ tOr: 2,
+ tAnd: 3,
+ tEQ: 5,
+ tLT: 5,
+ tLTE: 5,
+ tGT: 5,
+ tGTE: 5,
+ tNE: 5,
+ tFlatten: 9,
+ tStar: 20,
+ tFilter: 21,
+ tDot: 40,
+ tNot: 45,
+ tLbrace: 50,
+ tLbracket: 55,
+ tLparen: 60,
+}
+
+// Parser holds state about the current expression being parsed.
+type Parser struct {
+ expression string
+ tokens []token
+ index int
+}
+
+// NewParser creates a new JMESPath parser.
+func NewParser() *Parser {
+ p := Parser{}
+ return &p
+}
+
+// Parse will compile a JMESPath expression.
+func (p *Parser) Parse(expression string) (ASTNode, error) {
+ lexer := NewLexer()
+ p.expression = expression
+ p.index = 0
+ tokens, err := lexer.tokenize(expression)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ p.tokens = tokens
+ parsed, err := p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ if p.current() != tEOF {
+ return ASTNode{}, p.syntaxError(fmt.Sprintf(
+ "Unexpected token at the end of the expresssion: %s", p.current()))
+ }
+ return parsed, nil
+}
+
+func (p *Parser) parseExpression(bindingPower int) (ASTNode, error) {
+ var err error
+ leftToken := p.lookaheadToken(0)
+ p.advance()
+ leftNode, err := p.nud(leftToken)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ currentToken := p.current()
+ for bindingPower < bindingPowers[currentToken] {
+ p.advance()
+ leftNode, err = p.led(currentToken, leftNode)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ currentToken = p.current()
+ }
+ return leftNode, nil
+}
+
+func (p *Parser) parseIndexExpression() (ASTNode, error) {
+ if p.lookahead(0) == tColon || p.lookahead(1) == tColon {
+ return p.parseSliceExpression()
+ }
+ indexStr := p.lookaheadToken(0).value
+ parsedInt, err := strconv.Atoi(indexStr)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ indexNode := ASTNode{nodeType: ASTIndex, value: parsedInt}
+ p.advance()
+ if err := p.match(tRbracket); err != nil {
+ return ASTNode{}, err
+ }
+ return indexNode, nil
+}
+
+func (p *Parser) parseSliceExpression() (ASTNode, error) {
+ parts := []*int{nil, nil, nil}
+ index := 0
+ current := p.current()
+ for current != tRbracket && index < 3 {
+ if current == tColon {
+ index++
+ p.advance()
+ } else if current == tNumber {
+ parsedInt, err := strconv.Atoi(p.lookaheadToken(0).value)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ parts[index] = &parsedInt
+ p.advance()
+ } else {
+ return ASTNode{}, p.syntaxError(
+ "Expected tColon or tNumber" + ", received: " + p.current().String())
+ }
+ current = p.current()
+ }
+ if err := p.match(tRbracket); err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTSlice,
+ value: parts,
+ }, nil
+}
+
+func (p *Parser) match(tokenType tokType) error {
+ if p.current() == tokenType {
+ p.advance()
+ return nil
+ }
+ return p.syntaxError("Expected " + tokenType.String() + ", received: " + p.current().String())
+}
+
+func (p *Parser) led(tokenType tokType, node ASTNode) (ASTNode, error) {
+ switch tokenType {
+ case tDot:
+ if p.current() != tStar {
+ right, err := p.parseDotRHS(bindingPowers[tDot])
+ return ASTNode{
+ nodeType: ASTSubexpression,
+ children: []ASTNode{node, right},
+ }, err
+ }
+ p.advance()
+ right, err := p.parseProjectionRHS(bindingPowers[tDot])
+ return ASTNode{
+ nodeType: ASTValueProjection,
+ children: []ASTNode{node, right},
+ }, err
+ case tPipe:
+ right, err := p.parseExpression(bindingPowers[tPipe])
+ return ASTNode{nodeType: ASTPipe, children: []ASTNode{node, right}}, err
+ case tOr:
+ right, err := p.parseExpression(bindingPowers[tOr])
+ return ASTNode{nodeType: ASTOrExpression, children: []ASTNode{node, right}}, err
+ case tAnd:
+ right, err := p.parseExpression(bindingPowers[tAnd])
+ return ASTNode{nodeType: ASTAndExpression, children: []ASTNode{node, right}}, err
+ case tLparen:
+ name := node.value
+ var args []ASTNode
+ for p.current() != tRparen {
+ expression, err := p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ if p.current() == tComma {
+ if err := p.match(tComma); err != nil {
+ return ASTNode{}, err
+ }
+ }
+ args = append(args, expression)
+ }
+ if err := p.match(tRparen); err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTFunctionExpression,
+ value: name,
+ children: args,
+ }, nil
+ case tFilter:
+ return p.parseFilter(node)
+ case tFlatten:
+ left := ASTNode{nodeType: ASTFlatten, children: []ASTNode{node}}
+ right, err := p.parseProjectionRHS(bindingPowers[tFlatten])
+ return ASTNode{
+ nodeType: ASTProjection,
+ children: []ASTNode{left, right},
+ }, err
+ case tEQ, tNE, tGT, tGTE, tLT, tLTE:
+ right, err := p.parseExpression(bindingPowers[tokenType])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTComparator,
+ value: tokenType,
+ children: []ASTNode{node, right},
+ }, nil
+ case tLbracket:
+ tokenType := p.current()
+ var right ASTNode
+ var err error
+ if tokenType == tNumber || tokenType == tColon {
+ right, err = p.parseIndexExpression()
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return p.projectIfSlice(node, right)
+ }
+ // Otherwise this is a projection.
+ if err := p.match(tStar); err != nil {
+ return ASTNode{}, err
+ }
+ if err := p.match(tRbracket); err != nil {
+ return ASTNode{}, err
+ }
+ right, err = p.parseProjectionRHS(bindingPowers[tStar])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTProjection,
+ children: []ASTNode{node, right},
+ }, nil
+ }
+ return ASTNode{}, p.syntaxError("Unexpected token: " + tokenType.String())
+}
+
+func (p *Parser) nud(token token) (ASTNode, error) {
+ switch token.tokenType {
+ case tJSONLiteral:
+ var parsed interface{}
+ err := json.Unmarshal([]byte(token.value), &parsed)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{nodeType: ASTLiteral, value: parsed}, nil
+ case tStringLiteral:
+ return ASTNode{nodeType: ASTLiteral, value: token.value}, nil
+ case tUnquotedIdentifier:
+ return ASTNode{
+ nodeType: ASTField,
+ value: token.value,
+ }, nil
+ case tQuotedIdentifier:
+ node := ASTNode{nodeType: ASTField, value: token.value}
+ if p.current() == tLparen {
+ return ASTNode{}, p.syntaxErrorToken("Can't have quoted identifier as function name.", token)
+ }
+ return node, nil
+ case tStar:
+ left := ASTNode{nodeType: ASTIdentity}
+ var right ASTNode
+ var err error
+ if p.current() == tRbracket {
+ right = ASTNode{nodeType: ASTIdentity}
+ } else {
+ right, err = p.parseProjectionRHS(bindingPowers[tStar])
+ }
+ return ASTNode{nodeType: ASTValueProjection, children: []ASTNode{left, right}}, err
+ case tFilter:
+ return p.parseFilter(ASTNode{nodeType: ASTIdentity})
+ case tLbrace:
+ return p.parseMultiSelectHash()
+ case tFlatten:
+ left := ASTNode{
+ nodeType: ASTFlatten,
+ children: []ASTNode{{nodeType: ASTIdentity}},
+ }
+ right, err := p.parseProjectionRHS(bindingPowers[tFlatten])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{nodeType: ASTProjection, children: []ASTNode{left, right}}, nil
+ case tLbracket:
+ tokenType := p.current()
+ //var right ASTNode
+ if tokenType == tNumber || tokenType == tColon {
+ right, err := p.parseIndexExpression()
+ if err != nil {
+ return ASTNode{}, nil
+ }
+ return p.projectIfSlice(ASTNode{nodeType: ASTIdentity}, right)
+ } else if tokenType == tStar && p.lookahead(1) == tRbracket {
+ p.advance()
+ p.advance()
+ right, err := p.parseProjectionRHS(bindingPowers[tStar])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTProjection,
+ children: []ASTNode{{nodeType: ASTIdentity}, right},
+ }, nil
+ } else {
+ return p.parseMultiSelectList()
+ }
+ case tCurrent:
+ return ASTNode{nodeType: ASTCurrentNode}, nil
+ case tExpref:
+ expression, err := p.parseExpression(bindingPowers[tExpref])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{nodeType: ASTExpRef, children: []ASTNode{expression}}, nil
+ case tNot:
+ expression, err := p.parseExpression(bindingPowers[tNot])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{nodeType: ASTNotExpression, children: []ASTNode{expression}}, nil
+ case tLparen:
+ expression, err := p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ if err := p.match(tRparen); err != nil {
+ return ASTNode{}, err
+ }
+ return expression, nil
+ case tEOF:
+ return ASTNode{}, p.syntaxErrorToken("Incomplete expression", token)
+ }
+
+ return ASTNode{}, p.syntaxErrorToken("Invalid token: "+token.tokenType.String(), token)
+}
+
+func (p *Parser) parseMultiSelectList() (ASTNode, error) {
+ var expressions []ASTNode
+ for {
+ expression, err := p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ expressions = append(expressions, expression)
+ if p.current() == tRbracket {
+ break
+ }
+ err = p.match(tComma)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ }
+ err := p.match(tRbracket)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return ASTNode{
+ nodeType: ASTMultiSelectList,
+ children: expressions,
+ }, nil
+}
+
+func (p *Parser) parseMultiSelectHash() (ASTNode, error) {
+ var children []ASTNode
+ for {
+ keyToken := p.lookaheadToken(0)
+ if err := p.match(tUnquotedIdentifier); err != nil {
+ if err := p.match(tQuotedIdentifier); err != nil {
+ return ASTNode{}, p.syntaxError("Expected tQuotedIdentifier or tUnquotedIdentifier")
+ }
+ }
+ keyName := keyToken.value
+ err := p.match(tColon)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ value, err := p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ node := ASTNode{
+ nodeType: ASTKeyValPair,
+ value: keyName,
+ children: []ASTNode{value},
+ }
+ children = append(children, node)
+ if p.current() == tComma {
+ err := p.match(tComma)
+ if err != nil {
+ return ASTNode{}, nil
+ }
+ } else if p.current() == tRbrace {
+ err := p.match(tRbrace)
+ if err != nil {
+ return ASTNode{}, nil
+ }
+ break
+ }
+ }
+ return ASTNode{
+ nodeType: ASTMultiSelectHash,
+ children: children,
+ }, nil
+}
+
+func (p *Parser) projectIfSlice(left ASTNode, right ASTNode) (ASTNode, error) {
+ indexExpr := ASTNode{
+ nodeType: ASTIndexExpression,
+ children: []ASTNode{left, right},
+ }
+ if right.nodeType == ASTSlice {
+ right, err := p.parseProjectionRHS(bindingPowers[tStar])
+ return ASTNode{
+ nodeType: ASTProjection,
+ children: []ASTNode{indexExpr, right},
+ }, err
+ }
+ return indexExpr, nil
+}
+func (p *Parser) parseFilter(node ASTNode) (ASTNode, error) {
+ var right, condition ASTNode
+ var err error
+ condition, err = p.parseExpression(0)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ if err := p.match(tRbracket); err != nil {
+ return ASTNode{}, err
+ }
+ if p.current() == tFlatten {
+ right = ASTNode{nodeType: ASTIdentity}
+ } else {
+ right, err = p.parseProjectionRHS(bindingPowers[tFilter])
+ if err != nil {
+ return ASTNode{}, err
+ }
+ }
+
+ return ASTNode{
+ nodeType: ASTFilterProjection,
+ children: []ASTNode{node, right, condition},
+ }, nil
+}
+
+func (p *Parser) parseDotRHS(bindingPower int) (ASTNode, error) {
+ lookahead := p.current()
+ if tokensOneOf([]tokType{tQuotedIdentifier, tUnquotedIdentifier, tStar}, lookahead) {
+ return p.parseExpression(bindingPower)
+ } else if lookahead == tLbracket {
+ if err := p.match(tLbracket); err != nil {
+ return ASTNode{}, err
+ }
+ return p.parseMultiSelectList()
+ } else if lookahead == tLbrace {
+ if err := p.match(tLbrace); err != nil {
+ return ASTNode{}, err
+ }
+ return p.parseMultiSelectHash()
+ }
+ return ASTNode{}, p.syntaxError("Expected identifier, lbracket, or lbrace")
+}
+
+func (p *Parser) parseProjectionRHS(bindingPower int) (ASTNode, error) {
+ current := p.current()
+ if bindingPowers[current] < 10 {
+ return ASTNode{nodeType: ASTIdentity}, nil
+ } else if current == tLbracket {
+ return p.parseExpression(bindingPower)
+ } else if current == tFilter {
+ return p.parseExpression(bindingPower)
+ } else if current == tDot {
+ err := p.match(tDot)
+ if err != nil {
+ return ASTNode{}, err
+ }
+ return p.parseDotRHS(bindingPower)
+ } else {
+ return ASTNode{}, p.syntaxError("Error")
+ }
+}
+
+func (p *Parser) lookahead(number int) tokType {
+ return p.lookaheadToken(number).tokenType
+}
+
+func (p *Parser) current() tokType {
+ return p.lookahead(0)
+}
+
+func (p *Parser) lookaheadToken(number int) token {
+ return p.tokens[p.index+number]
+}
+
+func (p *Parser) advance() {
+ p.index++
+}
+
+func tokensOneOf(elements []tokType, token tokType) bool {
+ for _, elem := range elements {
+ if elem == token {
+ return true
+ }
+ }
+ return false
+}
+
+func (p *Parser) syntaxError(msg string) SyntaxError {
+ return SyntaxError{
+ msg: msg,
+ Expression: p.expression,
+ Offset: p.lookaheadToken(0).position,
+ }
+}
+
+// Create a SyntaxError based on the provided token.
+// This differs from syntaxError() which creates a SyntaxError
+// based on the current lookahead token.
+func (p *Parser) syntaxErrorToken(msg string, t token) SyntaxError {
+ return SyntaxError{
+ msg: msg,
+ Expression: p.expression,
+ Offset: t.position,
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-02 15:33:24 +0000