package jsonpath const ( exprError = iota exprEOF exprParenLeft exprParenRight exprNumber exprPath exprBool exprNull exprString exprOperators exprOpEq exprOpNeq exprOpNot exprOpLt exprOpLe exprOpGt exprOpGe exprOpAnd exprOpOr exprOpPlus exprOpPlusUn exprOpMinus exprOpMinusUn exprOpSlash exprOpStar exprOpHat exprOpPercent exprOpExclam ) var exprTokenNames = map[int]string{ exprError: "error", exprEOF: "EOF", exprParenLeft: "(", exprParenRight: ")", exprNumber: "number", exprPath: "path", exprBool: "bool", exprNull: "null", exprString: "string", exprOpEq: "==", exprOpNeq: "!=", exprOpNot: "!", exprOpLt: "<", exprOpLe: "<=", exprOpGt: ">", exprOpGe: ">=", exprOpAnd: "&&", exprOpOr: "||", exprOpPlus: "+", exprOpPlusUn: "(+)", exprOpMinus: "-", exprOpMinusUn: "(-)", exprOpSlash: "/", exprOpStar: "*", exprOpHat: "^", exprOpPercent: "%", exprOpExclam: "!", } var EXPRESSION = lexExprText func lexExprText(l lexer, state *intStack) stateFn { ignoreSpaceRun(l) cur := l.peek() var next stateFn switch cur { case '(': l.take() state.push(exprParenLeft) l.emit(exprParenLeft) next = lexExprText case ')': if top, ok := state.peek(); ok && top != exprParenLeft { next = l.errorf("Received %#U but has no matching (", cur) break } state.pop() l.take() l.emit(exprParenRight) next = lexOneValue case '!': l.take() l.emit(exprOpNot) next = lexExprText case '+': l.take() l.emit(exprOpPlusUn) next = lexExprText case '-': l.take() l.emit(exprOpMinusUn) next = lexExprText case '@': //, '$': // Only support current key location l.take() takePath(l) l.emit(exprPath) next = lexOneValue case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': takeNumeric(l) l.emit(exprNumber) next = lexOneValue case 't': takeExactSequence(l, bytesTrue) l.emit(exprBool) next = lexOneValue case 'f': takeExactSequence(l, bytesFalse) l.emit(exprBool) next = lexOneValue case 'n': takeExactSequence(l, bytesNull) l.emit(exprNull) next = lexOneValue case '"': err := l.takeString() if err != nil { return l.errorf("Could not take string because %q", err) } l.emit(exprString) next = lexOneValue case eof: l.emit(exprEOF) // next = nil default: return l.errorf("Unrecognized sequence in expression: %#U", cur) } return next } func lexOneValue(l lexer, state *intStack) stateFn { var next stateFn cur := l.peek() switch cur { case '+': l.take() l.emit(exprOpPlus) next = lexExprText case '-': l.take() l.emit(exprOpMinus) next = lexExprText case '*': l.take() l.emit(exprOpStar) next = lexExprText case '/': l.take() l.emit(exprOpSlash) next = lexExprText case '%': l.take() l.emit(exprOpPercent) next = lexExprText case '^': l.take() l.emit(exprOpHat) next = lexExprText case '<': l.take() cur = l.peek() if cur == '=' { l.take() l.emit(exprOpLe) } else { l.emit(exprOpLt) } next = lexExprText case '>': l.take() cur = l.peek() if cur == '=' { l.take() l.emit(exprOpGe) } else { l.emit(exprOpGt) } next = lexExprText case '&': l.take() cur = l.take() if cur != '&' { return l.errorf("Expected double & instead of %#U", cur) } l.emit(exprOpAnd) next = lexExprText case '|': l.take() cur = l.take() if cur != '|' { return l.errorf("Expected double | instead of %#U", cur) } l.emit(exprOpOr) next = lexExprText case '=': l.take() cur = l.take() if cur != '=' { return l.errorf("Expected double = instead of %#U", cur) } l.emit(exprOpEq) next = lexExprText case '!': l.take() cur = l.take() if cur != '=' { return l.errorf("Expected = for != instead of %#U", cur) } l.emit(exprOpNeq) next = lexExprText case ')': if top, ok := state.peek(); ok && top != exprParenLeft { next = l.errorf("Received %#U but has no matching (", cur) break } state.pop() l.take() l.emit(exprParenRight) next = lexOneValue case eof: l.emit(exprEOF) default: return l.errorf("Unrecognized sequence in expression: %#U", cur) } return next } func takeNumeric(l lexer) { takeDigits(l) if l.peek() == '.' { l.take() takeDigits(l) } if l.peek() == 'e' || l.peek() == 'E' { l.take() if l.peek() == '+' || l.peek() == '-' { l.take() takeDigits(l) } else { takeDigits(l) } } } func takePath(l lexer) { inQuotes := false var prev int = 0 // capture until end of path - ugly takeLoop: for { cur := l.peek() switch cur { case '"': if prev != '\\' { inQuotes = !inQuotes } l.take() case ' ': if !inQuotes { break takeLoop } l.take() case eof: break takeLoop default: l.take() } prev = cur } } func lexExprEnd(l lexer, state *intStack) stateFn { cur := l.take() if cur != eof { return l.errorf("Expected EOF but received %#U", cur) } l.emit(exprEOF) return nil }