@ -16,6 +16,7 @@ package promql
import (
"fmt"
"strings"
"unicode"
"unicode/utf8"
)
@ -465,6 +466,9 @@ func lexStatements(l *lexer) stateFn {
case r == '"' || r == '\'' :
l . stringOpen = r
return lexString
case r == '`' :
l . stringOpen = r
return lexRawString
case isAlpha ( r ) || r == ':' :
l . backup ( )
return lexKeywordOrIdentifier
@ -523,6 +527,9 @@ func lexInsideBraces(l *lexer) stateFn {
case r == '"' || r == '\'' :
l . stringOpen = r
return lexString
case r == '`' :
l . stringOpen = r
return lexRawString
case r == '=' :
if l . next ( ) == '~' {
l . emit ( itemEQLRegex )
@ -583,16 +590,79 @@ func lexValueSequence(l *lexer) stateFn {
return lexValueSequence
}
// lexEscape scans a string escape sequence. The initial escaping character (\)
// has already been seen.
//
// NOTE: This function as well as the helper function digitVal() and associated
// tests have been adapted from the corresponding functions in the "go/scanner"
// package of the Go standard library to work for Prometheus-style strings.
// None of the actual escaping/quoting logic was changed in this function - it
// was only modified to integrate with our lexer.
func lexEscape ( l * lexer ) {
var n int
var base , max uint32
ch := l . next ( )
switch ch {
case 'a' , 'b' , 'f' , 'n' , 'r' , 't' , 'v' , '\\' , l . stringOpen :
return
case '0' , '1' , '2' , '3' , '4' , '5' , '6' , '7' :
n , base , max = 3 , 8 , 255
case 'x' :
ch = l . next ( )
n , base , max = 2 , 16 , 255
case 'u' :
ch = l . next ( )
n , base , max = 4 , 16 , unicode . MaxRune
case 'U' :
ch = l . next ( )
n , base , max = 8 , 16 , unicode . MaxRune
case eof :
l . errorf ( "escape sequence not terminated" )
default :
l . errorf ( "unknown escape sequence %#U" , ch )
}
var x uint32
for n > 0 {
d := uint32 ( digitVal ( ch ) )
if d >= base {
if ch == eof {
l . errorf ( "escape sequence not terminated" )
}
l . errorf ( "illegal character %#U in escape sequence" , ch )
}
x = x * base + d
ch = l . next ( )
n --
}
if x > max || 0xD800 <= x && x < 0xE000 {
l . errorf ( "escape sequence is an invalid Unicode code point" )
}
}
// digitVal returns the digit value of a rune or 16 in case the rune does not
// represent a valid digit.
func digitVal ( ch rune ) int {
switch {
case '0' <= ch && ch <= '9' :
return int ( ch - '0' )
case 'a' <= ch && ch <= 'f' :
return int ( ch - 'a' + 10 )
case 'A' <= ch && ch <= 'F' :
return int ( ch - 'A' + 10 )
}
return 16 // Larger than any legal digit val.
}
// lexString scans a quoted string. The initial quote has already been seen.
func lexString ( l * lexer ) stateFn {
Loop :
for {
switch l . next ( ) {
case '\\' :
if r := l . next ( ) ; r != eof && r != '\n' {
break
}
fallthrough
lexEscape ( l )
case eof , '\n' :
return l . errorf ( "unterminated quoted string" )
case l . stringOpen :
@ -603,6 +673,21 @@ Loop:
return lexStatements
}
// lexRawString scans a raw quoted string. The initial quote has already been seen.
func lexRawString ( l * lexer ) stateFn {
Loop :
for {
switch l . next ( ) {
case eof :
return l . errorf ( "unterminated raw string" )
case l . stringOpen :
break Loop
}
}
l . emit ( itemString )
return lexStatements
}
// lexSpace scans a run of space characters. One space has already been seen.
func lexSpace ( l * lexer ) stateFn {
for isSpace ( l . peek ( ) ) {
Julius Volz
9 years ago