From a18a13fb09eac00cdacf1f74080524182b7243de Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Mon, 6 Jun 2016 00:55:30 +0100 Subject: update vendor --- vendor/github.com/jmespath/go-jmespath/parser.go | 603 +++++++++++++++++++++++ 1 file changed, 603 insertions(+) create mode 100644 vendor/github.com/jmespath/go-jmespath/parser.go (limited to 'vendor/github.com/jmespath/go-jmespath/parser.go') 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, + } +} -- cgit v1.2.3