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Apache License
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# go-jsonnet
This is a port of [jsonnet](http://jsonnet.org/) to go. It is very much a work in progress.
This implementation is largely based on the the [jsonnet C++ implementation](https://github.com/google/jsonnet).

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package jsonnet
import (
"bytes"
"fmt"
"strconv"
"strings"
"unicode/utf8"
)
//////////////////////////////////////////////////////////////////////////////
// Fodder
//
// Fodder is stuff that is usually thrown away by lexers/preprocessors but is
// kept so that the source can be round tripped with full fidelity.
type fodderKind int
const (
fodderWhitespace fodderKind = iota
fodderCommentC
fodderCommentCpp
fodderCommentHash
)
type fodderElement struct {
kind fodderKind
data string
}
type fodder []fodderElement
//////////////////////////////////////////////////////////////////////////////
// Token
type tokenKind int
const (
tokenInvalid tokenKind = iota
// Symbols
tokenBraceL
tokenBraceR
tokenBracketL
tokenBracketR
tokenColon
tokenComma
tokenDollar
tokenDot
tokenParenL
tokenParenR
tokenSemicolon
// Arbitrary length lexemes
tokenIdentifier
tokenNumber
tokenOperator
tokenStringDouble
tokenStringSingle
tokenStringBlock
// Keywords
tokenAssert
tokenElse
tokenError
tokenFalse
tokenFor
tokenFunction
tokenIf
tokenImport
tokenImportStr
tokenIn
tokenLocal
tokenNullLit
tokenTailStrict
tokenThen
tokenSelf
tokenSuper
tokenTrue
// A special token that holds line/column information about the end of the
// file.
tokenEndOfFile
)
type token struct {
kind tokenKind // The type of the token
fodder fodder // Any fodder the occurs before this token
data string // Content of the token if it is not a keyword
// Extra info for when kind == tokenStringBlock
stringBlockIndent string // The sequence of whitespace that indented the block.
stringBlockTermIndent string // This is always fewer whitespace characters than in stringBlockIndent.
loc LocationRange
}
type tokens []token
//////////////////////////////////////////////////////////////////////////////
// Helpers
func isUpper(r rune) bool {
return r >= 'A' && r <= 'Z'
}
func isLower(r rune) bool {
return r >= 'a' && r <= 'z'
}
func isNumber(r rune) bool {
return r >= '0' && r <= '9'
}
func isIdentifierFirst(r rune) bool {
return isUpper(r) || isLower(r) || r == '_'
}
func isIdentifier(r rune) bool {
return isIdentifierFirst(r) || isNumber(r)
}
func isSymbol(r rune) bool {
switch r {
case '&', '|', '^', '=', '<', '>', '*', '/', '%', '#':
return true
}
return false
}
// Check that b has at least the same whitespace prefix as a and returns the
// amount of this whitespace, otherwise returns 0. If a has no whitespace
// prefix than return 0.
func checkWhitespace(a, b string) int {
i := 0
for ; i < len(a); i++ {
if a[i] != ' ' && a[i] != '\t' {
// a has run out of whitespace and b matched up to this point. Return
// result.
return i
}
if i >= len(b) {
// We ran off the edge of b while a still has whitespace. Return 0 as
// failure.
return 0
}
if a[i] != b[i] {
// a has whitespace but b does not. Return 0 as failure.
return 0
}
}
// We ran off the end of a and b kept up
return i
}
//////////////////////////////////////////////////////////////////////////////
// Lexer
type lexer struct {
fileName string // The file name being lexed, only used for errors
input string // The input string
pos int // Current byte position in input
lineNumber int // Current line number for pos
lineStart int // Byte position of start of line
// Data about the state position of the lexer before previous call to
// 'next'. If this state is lost then prevPos is set to lexEOF and panic
// ensues.
prevPos int // Byte position of last rune read
prevLineNumber int // The line number before last rune read
prevLineStart int // The line start before last rune read
tokens tokens // The tokens that we've generated so far
// Information about the token we are working on right now
fodder fodder
tokenStart int
tokenStartLoc Location
}
const lexEOF = -1
func makeLexer(fn string, input string) *lexer {
return &lexer{
fileName: fn,
input: input,
lineNumber: 1,
prevPos: lexEOF,
prevLineNumber: 1,
tokenStartLoc: Location{Line: 1, Column: 1},
}
}
// next returns the next rune in the input.
func (l *lexer) next() rune {
if int(l.pos) >= len(l.input) {
l.prevPos = l.pos
return lexEOF
}
r, w := utf8.DecodeRuneInString(l.input[l.pos:])
l.prevPos = l.pos
l.pos += w
if r == '\n' {
l.prevLineNumber = l.lineNumber
l.prevLineStart = l.lineStart
l.lineNumber += 1
l.lineStart = l.pos
}
return r
}
func (l *lexer) acceptN(n int) {
for i := 0; i < n; i++ {
l.next()
}
}
// peek returns but does not consume the next rune in the input.
func (l *lexer) peek() rune {
r := l.next()
l.backup()
return r
}
// backup steps back one rune. Can only be called once per call of next.
func (l *lexer) backup() {
if l.prevPos == lexEOF {
panic("backup called with no valid previous rune")
}
l.lineNumber = l.prevLineNumber
l.lineStart = l.prevLineStart
l.pos = l.prevPos
l.prevPos = lexEOF
}
func (l *lexer) location() Location {
return Location{Line: l.lineNumber, Column: l.pos - l.lineStart + 1}
}
func (l *lexer) prevLocation() Location {
if l.prevPos == lexEOF {
panic("prevLocation called with no valid previous rune")
}
return Location{Line: l.prevLineNumber, Column: l.prevPos - l.prevLineStart + 1}
}
// Reset the current working token start to the current cursor position. This
// may throw away some characters. This does not throw away any accumulated
// fodder.
func (l *lexer) resetTokenStart() {
l.tokenStart = l.pos
l.tokenStartLoc = l.location()
}
func (l *lexer) emitFullToken(kind tokenKind, data, stringBlockIndent, stringBlockTermIndent string) {
l.tokens = append(l.tokens, token{
kind: kind,
fodder: l.fodder,
data: data,
stringBlockIndent: stringBlockIndent,
stringBlockTermIndent: stringBlockTermIndent,
loc: makeLocationRange(l.fileName, l.tokenStartLoc, l.location()),
})
l.fodder = fodder{}
}
func (l *lexer) emitToken(kind tokenKind) {
l.emitFullToken(kind, l.input[l.tokenStart:l.pos], "", "")
l.resetTokenStart()
}
func (l *lexer) addWhitespaceFodder() {
fodderData := l.input[l.tokenStart:l.pos]
if len(l.fodder) == 0 || l.fodder[len(l.fodder)-1].kind != fodderWhitespace {
l.fodder = append(l.fodder, fodderElement{kind: fodderWhitespace, data: fodderData})
} else {
l.fodder[len(l.fodder)-1].data += fodderData
}
l.resetTokenStart()
}
func (l *lexer) addCommentFodder(kind fodderKind) {
fodderData := l.input[l.tokenStart:l.pos]
l.fodder = append(l.fodder, fodderElement{kind: kind, data: fodderData})
l.resetTokenStart()
}
func (l *lexer) addFodder(kind fodderKind, data string) {
l.fodder = append(l.fodder, fodderElement{kind: kind, data: data})
}
// lexNumber will consume a number and emit a token. It is assumed
// that the next rune to be served by the lexer will be a leading digit.
func (l *lexer) lexNumber() error {
// This function should be understood with reference to the linked image:
// http://www.json.org/number.gif
// Note, we deviate from the json.org documentation as follows:
// There is no reason to lex negative numbers as atomic tokens, it is better to parse them
// as a unary operator combined with a numeric literal. This avoids x-1 being tokenized as
// <identifier> <number> instead of the intended <identifier> <binop> <number>.
type numLexState int
const (
numBegin numLexState = iota
numAfterZero
numAfterOneToNine
numAfterDot
numAfterDigit
numAfterE
numAfterExpSign
numAfterExpDigit
)
state := numBegin
for true {
r := l.next()
switch state {
case numBegin:
switch {
case r == '0':
state = numAfterZero
case r >= '1' && r <= '9':
state = numAfterOneToNine
default:
return makeStaticErrorPoint(
"Couldn't lex number", l.fileName, l.prevLocation())
}
case numAfterZero:
switch r {
case '.':
state = numAfterDot
case 'e', 'E':
state = numAfterE
default:
goto end
}
case numAfterOneToNine:
switch {
case r == '.':
state = numAfterDot
case r == 'e' || r == 'E':
state = numAfterE
case r >= '0' && r <= '9':
state = numAfterOneToNine
default:
goto end
}
case numAfterDot:
switch {
case r >= '0' && r <= '9':
state = numAfterDigit
default:
return makeStaticErrorPoint(
fmt.Sprintf("Couldn't lex number, junk after decimal point: %v", strconv.QuoteRuneToASCII(r)),
l.fileName, l.prevLocation())
}
case numAfterDigit:
switch {
case r == 'e' || r == 'E':
state = numAfterE
case r >= '0' && r <= '9':
state = numAfterDigit
default:
goto end
}
case numAfterE:
switch {
case r == '+' || r == '-':
state = numAfterExpSign
case r >= '0' && r <= '9':
state = numAfterExpDigit
default:
return makeStaticErrorPoint(
fmt.Sprintf("Couldn't lex number, junk after 'E': %v", strconv.QuoteRuneToASCII(r)),
l.fileName, l.prevLocation())
}
case numAfterExpSign:
if r >= '0' && r <= '9' {
state = numAfterExpDigit
} else {
return makeStaticErrorPoint(
fmt.Sprintf("Couldn't lex number, junk after exponent sign: %v", strconv.QuoteRuneToASCII(r)),
l.fileName, l.prevLocation())
}
case numAfterExpDigit:
if r >= '0' && r <= '9' {
state = numAfterExpDigit
} else {
goto end
}
}
}
end:
l.backup()
l.emitToken(tokenNumber)
return nil
}
// lexIdentifier will consume a identifer and emit a token. It is assumed
// that the next rune to be served by the lexer will be a leading digit. This
// may emit a keyword or an identifier.
func (l *lexer) lexIdentifier() {
r := l.next()
if !isIdentifierFirst(r) {
panic("Unexpected character in lexIdentifier")
}
for ; r != lexEOF; r = l.next() {
if !isIdentifier(r) {
break
}
}
l.backup()
switch l.input[l.tokenStart:l.pos] {
case "assert":
l.emitToken(tokenAssert)
case "else":
l.emitToken(tokenElse)
case "error":
l.emitToken(tokenError)
case "false":
l.emitToken(tokenFalse)
case "for":
l.emitToken(tokenFor)
case "function":
l.emitToken(tokenFunction)
case "if":
l.emitToken(tokenIf)
case "import":
l.emitToken(tokenImport)
case "importstr":
l.emitToken(tokenImportStr)
case "in":
l.emitToken(tokenIn)
case "local":
l.emitToken(tokenLocal)
case "null":
l.emitToken(tokenNullLit)
case "self":
l.emitToken(tokenSelf)
case "super":
l.emitToken(tokenSuper)
case "tailstrict":
l.emitToken(tokenTailStrict)
case "then":
l.emitToken(tokenThen)
case "true":
l.emitToken(tokenTrue)
default:
// Not a keyword, assume it is an identifier
l.emitToken(tokenIdentifier)
}
}
// lexSymbol will lex a token that starts with a symbol. This could be a
// comment, block quote or an operator. This function assumes that the next
// rune to be served by the lexer will be the first rune of the new token.
func (l *lexer) lexSymbol() error {
r := l.next()
// Single line C++ style comment
if r == '/' && l.peek() == '/' {
l.next()
l.resetTokenStart() // Throw out the leading //
for r = l.next(); r != lexEOF && r != '\n'; r = l.next() {
}
// Leave the '\n' in the lexer to be fodder for the next round
l.backup()
l.addCommentFodder(fodderCommentCpp)
return nil
}
if r == '#' {
l.resetTokenStart() // Throw out the leading #
for r = l.next(); r != lexEOF && r != '\n'; r = l.next() {
}
// Leave the '\n' in the lexer to be fodder for the next round
l.backup()
l.addCommentFodder(fodderCommentHash)
return nil
}
if r == '/' && l.peek() == '*' {
commentStartLoc := l.tokenStartLoc
l.next() // consume the '*'
l.resetTokenStart() // Throw out the leading /*
for r = l.next(); ; r = l.next() {
if r == lexEOF {
return makeStaticErrorPoint("Multi-line comment has no terminating */.",
l.fileName, commentStartLoc)
}
if r == '*' && l.peek() == '/' {
commentData := l.input[l.tokenStart : l.pos-1] // Don't include trailing */
l.addFodder(fodderCommentC, commentData)
l.next() // Skip past '/'
l.resetTokenStart() // Start next token at this point
return nil
}
}
}
if r == '|' && strings.HasPrefix(l.input[l.pos:], "||\n") {
commentStartLoc := l.tokenStartLoc
l.acceptN(3) // Skip "||\n"
var cb bytes.Buffer
// Skip leading blank lines
for r = l.next(); r == '\n'; r = l.next() {
cb.WriteRune(r)
}
l.backup()
numWhiteSpace := checkWhitespace(l.input[l.pos:], l.input[l.pos:])
stringBlockIndent := l.input[l.pos : l.pos+numWhiteSpace]
if numWhiteSpace == 0 {
return makeStaticErrorPoint("Text block's first line must start with whitespace.",
l.fileName, commentStartLoc)
}
for {
if numWhiteSpace <= 0 {
panic("Unexpected value for numWhiteSpace")
}
l.acceptN(numWhiteSpace)
for r = l.next(); r != '\n'; r = l.next() {
if r == lexEOF {
return makeStaticErrorPoint("Unexpected EOF",
l.fileName, commentStartLoc)
}
cb.WriteRune(r)
}
cb.WriteRune('\n')
// Skip any blank lines
for r = l.next(); r == '\n'; r = l.next() {
cb.WriteRune(r)
}
l.backup()
// Look at the next line
numWhiteSpace = checkWhitespace(stringBlockIndent, l.input[l.pos:])
if numWhiteSpace == 0 {
// End of the text block
var stringBlockTermIndent string
for r = l.next(); r == ' ' || r == '\t'; r = l.next() {
stringBlockTermIndent += string(r)
}
l.backup()
if !strings.HasPrefix(l.input[l.pos:], "|||") {
return makeStaticErrorPoint("Text block not terminated with |||",
l.fileName, commentStartLoc)
}
l.acceptN(3) // Skip '|||'
l.emitFullToken(tokenStringBlock, cb.String(),
stringBlockIndent, stringBlockTermIndent)
l.resetTokenStart()
return nil
}
}
}
// Assume any string of symbols is a single operator.
for r = l.next(); isSymbol(r); r = l.next() {
}
l.backup()
l.emitToken(tokenOperator)
return nil
}
func lex(fn string, input string) (tokens, error) {
l := makeLexer(fn, input)
var err error
for r := l.next(); r != lexEOF; r = l.next() {
switch r {
case ' ', '\t', '\r', '\n':
l.addWhitespaceFodder()
continue
case '{':
l.emitToken(tokenBraceL)
case '}':
l.emitToken(tokenBraceR)
case '[':
l.emitToken(tokenBracketL)
case ']':
l.emitToken(tokenBracketR)
case ':':
l.emitToken(tokenColon)
case ',':
l.emitToken(tokenComma)
case '$':
l.emitToken(tokenDollar)
case '.':
l.emitToken(tokenDot)
case '(':
l.emitToken(tokenParenL)
case ')':
l.emitToken(tokenParenR)
case ';':
l.emitToken(tokenSemicolon)
// Operators
case '!':
if l.peek() == '=' {
_ = l.next()
}
l.emitToken(tokenOperator)
case '~', '+', '-':
l.emitToken(tokenOperator)
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
l.backup()
err = l.lexNumber()
if err != nil {
return nil, err
}
// String literals
case '"':
stringStartLoc := l.prevLocation()
l.resetTokenStart() // Don't include the quotes in the token data
for r = l.next(); ; r = l.next() {
if r == lexEOF {
return nil, makeStaticErrorPoint("Unterminated String", l.fileName, stringStartLoc)
}
if r == '"' {
l.backup()
l.emitToken(tokenStringDouble)
_ = l.next()
l.resetTokenStart()
break
}
if r == '\\' && l.peek() != lexEOF {
r = l.next()
}
}
case '\'':
stringStartLoc := l.prevLocation()
l.resetTokenStart() // Don't include the quotes in the token data
for r = l.next(); ; r = l.next() {
if r == lexEOF {
return nil, makeStaticErrorPoint("Unterminated String", l.fileName, stringStartLoc)
}
if r == '\'' {
l.backup()
l.emitToken(tokenStringSingle)
r = l.next()
l.resetTokenStart()
break
}
if r == '\\' && l.peek() != lexEOF {
r = l.next()
}
}
default:
if isIdentifierFirst(r) {
l.backup()
l.lexIdentifier()
} else if isSymbol(r) {
l.backup()
err = l.lexSymbol()
if err != nil {
return nil, err
}
} else {
return nil, makeStaticErrorPoint(
fmt.Sprintf("Could not lex the character %s", strconv.QuoteRuneToASCII(r)),
l.fileName, l.prevLocation())
}
}
}
// We are currently at the EOF. Emit a special token to capture any
// trailing fodder
l.emitToken(tokenEndOfFile)
return l.tokens, nil
}

255
lexer_test.go Normal file
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@ -0,0 +1,255 @@
package jsonnet
import (
"testing"
)
type lexTest struct {
name string
input string
tokens tokens
errString string
}
var (
tEOF = token{kind: tokenEndOfFile}
)
var lexTests = []lexTest{
{"empty", "", tokens{}, ""},
{"whitespace", " \t\n\r\r\n", tokens{}, ""},
{"brace L", "{", tokens{{kind: tokenBraceL, data: "{"}}, ""},
{"brace R", "}", tokens{{kind: tokenBraceR, data: "}"}}, ""},
{"bracket L", "[", tokens{{kind: tokenBracketL, data: "["}}, ""},
{"bracket R", "]", tokens{{kind: tokenBracketR, data: "]"}}, ""},
{"colon", ":", tokens{{kind: tokenColon, data: ":"}}, ""},
{"comma", ",", tokens{{kind: tokenComma, data: ","}}, ""},
{"dollar", "$", tokens{{kind: tokenDollar, data: "$"}}, ""},
{"dot", ".", tokens{{kind: tokenDot, data: "."}}, ""},
{"paren L", "(", tokens{{kind: tokenParenL, data: "("}}, ""},
{"paren R", ")", tokens{{kind: tokenParenR, data: ")"}}, ""},
{"semicolon", ";", tokens{{kind: tokenSemicolon, data: ";"}}, ""},
{"not 1", "!", tokens{{kind: tokenOperator, data: "!"}}, ""},
{"not 2", "! ", tokens{{kind: tokenOperator, data: "!"}}, ""},
{"not equal", "!=", tokens{{kind: tokenOperator, data: "!="}}, ""},
{"tilde", "~", tokens{{kind: tokenOperator, data: "~"}}, ""},
{"plus", "+", tokens{{kind: tokenOperator, data: "+"}}, ""},
{"minus", "-", tokens{{kind: tokenOperator, data: "-"}}, ""},
{"number 0", "0", tokens{{kind: tokenNumber, data: "0"}}, ""},
{"number 1", "1", tokens{{kind: tokenNumber, data: "1"}}, ""},
{"number 1.0", "1.0", tokens{{kind: tokenNumber, data: "1.0"}}, ""},
{"number 0.1", "0.1", tokens{{kind: tokenNumber, data: "0.1"}}, ""},
{"number 0e100", "0e100", tokens{{kind: tokenNumber, data: "0e100"}}, ""},
{"number 1e100", "1e100", tokens{{kind: tokenNumber, data: "1e100"}}, ""},
{"number 1.1e100", "1.1e100", tokens{{kind: tokenNumber, data: "1.1e100"}}, ""},
{"number 1.1e-100", "1.1e-100", tokens{{kind: tokenNumber, data: "1.1e-100"}}, ""},
{"number 1.1e+100", "1.1e+100", tokens{{kind: tokenNumber, data: "1.1e+100"}}, ""},
{"number 0100", "0100", tokens{
{kind: tokenNumber, data: "0"},
{kind: tokenNumber, data: "100"},
}, ""},
{"number 10+10", "10+10", tokens{
{kind: tokenNumber, data: "10"},
{kind: tokenOperator, data: "+"},
{kind: tokenNumber, data: "10"},
}, ""},
{"number 1.+3", "1.+3", tokens{}, "number 1.+3:1:3 Couldn't lex number, junk after decimal point: '+'"},
{"number 1e!", "1e!", tokens{}, "number 1e!:1:3 Couldn't lex number, junk after 'E': '!'"},
{"number 1e+!", "1e+!", tokens{}, "number 1e+!:1:4 Couldn't lex number, junk after exponent sign: '!'"},
{"double string \"hi\"", "\"hi\"", tokens{{kind: tokenStringDouble, data: "hi"}}, ""},
{"double string \"hi nl\"", "\"hi\n\"", tokens{{kind: tokenStringDouble, data: "hi\n"}}, ""},
{"double string \"hi\\\"\"", "\"hi\\\"\"", tokens{{kind: tokenStringDouble, data: "hi\\\""}}, ""},
{"double string \"hi\\nl\"", "\"hi\\\n\"", tokens{{kind: tokenStringDouble, data: "hi\\\n"}}, ""},
{"double string \"hi", "\"hi", tokens{}, "double string \"hi:1:1 Unterminated String"},
{"single string 'hi'", "'hi'", tokens{{kind: tokenStringSingle, data: "hi"}}, ""},
{"single string 'hi nl'", "'hi\n'", tokens{{kind: tokenStringSingle, data: "hi\n"}}, ""},
{"single string 'hi\\''", "'hi\\''", tokens{{kind: tokenStringSingle, data: "hi\\'"}}, ""},
{"single string 'hi\\nl'", "'hi\\\n'", tokens{{kind: tokenStringSingle, data: "hi\\\n"}}, ""},
{"single string 'hi", "'hi", tokens{}, "single string 'hi:1:1 Unterminated String"},
{"assert", "assert", tokens{{kind: tokenAssert, data: "assert"}}, ""},
{"else", "else", tokens{{kind: tokenElse, data: "else"}}, ""},
{"error", "error", tokens{{kind: tokenError, data: "error"}}, ""},
{"false", "false", tokens{{kind: tokenFalse, data: "false"}}, ""},
{"for", "for", tokens{{kind: tokenFor, data: "for"}}, ""},
{"function", "function", tokens{{kind: tokenFunction, data: "function"}}, ""},
{"if", "if", tokens{{kind: tokenIf, data: "if"}}, ""},
{"import", "import", tokens{{kind: tokenImport, data: "import"}}, ""},
{"importstr", "importstr", tokens{{kind: tokenImportStr, data: "importstr"}}, ""},
{"in", "in", tokens{{kind: tokenIn, data: "in"}}, ""},
{"local", "local", tokens{{kind: tokenLocal, data: "local"}}, ""},
{"null", "null", tokens{{kind: tokenNullLit, data: "null"}}, ""},
{"self", "self", tokens{{kind: tokenSelf, data: "self"}}, ""},
{"super", "super", tokens{{kind: tokenSuper, data: "super"}}, ""},
{"tailstrict", "tailstrict", tokens{{kind: tokenTailStrict, data: "tailstrict"}}, ""},
{"then", "then", tokens{{kind: tokenThen, data: "then"}}, ""},
{"true", "true", tokens{{kind: tokenTrue, data: "true"}}, ""},
{"identifier", "foobar", tokens{{kind: tokenIdentifier, data: "foobar"}}, ""},
{"c++ comment", "// hi", tokens{}, ""}, // This test doesn't look at fodder (yet?)
{"hash comment", "# hi", tokens{}, ""}, // This test doesn't look at fodder (yet?)
{"c comment", "/* hi */", tokens{}, ""}, // This test doesn't look at fodder (yet?)
{
"block string spaces",
`|||
test
more
|||
foo
|||`,
tokens{
{
kind: tokenStringBlock,
data: "test\n more\n|||\n foo\n",
stringBlockIndent: " ",
stringBlockTermIndent: "",
},
},
"",
},
{
"block string tabs",
`|||
test
more
|||
foo
|||`,
tokens{
{
kind: tokenStringBlock,
data: "test\n more\n|||\n foo\n",
stringBlockIndent: "\t",
stringBlockTermIndent: "",
},
},
"",
},
{
"block string mixed",
`|||
test
more
|||
foo
|||`,
tokens{
{
kind: tokenStringBlock,
data: "test\n more\n|||\n foo\n",
stringBlockIndent: "\t \t",
stringBlockTermIndent: "",
},
},
"",
},
{
"block string blanks",
`|||
test
more
|||
foo
|||`,
tokens{
{
kind: tokenStringBlock,
data: "\ntest\n\n\n more\n|||\n foo\n",
stringBlockIndent: " ",
stringBlockTermIndent: "",
},
},
"",
},
{
"block string bad indent",
`|||
test
foo
|||`,
tokens{},
"block string bad indent:1:1 Text block not terminated with |||",
},
{
"block string eof",
`|||
test`,
tokens{},
"block string eof:1:1 Unexpected EOF",
},
{
"block string not term",
`|||
test
`,
tokens{},
"block string not term:1:1 Text block not terminated with |||",
},
{"op *", "*", tokens{{kind: tokenOperator, data: "*"}}, ""},
{"op /", "/", tokens{{kind: tokenOperator, data: "/"}}, ""},
{"op %", "%", tokens{{kind: tokenOperator, data: "%"}}, ""},
{"op &", "&", tokens{{kind: tokenOperator, data: "&"}}, ""},
{"op |", "|", tokens{{kind: tokenOperator, data: "|"}}, ""},
{"op ^", "^", tokens{{kind: tokenOperator, data: "^"}}, ""},
{"op =", "=", tokens{{kind: tokenOperator, data: "="}}, ""},
{"op <", "<", tokens{{kind: tokenOperator, data: "<"}}, ""},
{"op >", ">", tokens{{kind: tokenOperator, data: ">"}}, ""},
{"op >==|", ">==|", tokens{{kind: tokenOperator, data: ">==|"}}, ""},
{"junk", "💩", tokens{}, "junk:1:1 Could not lex the character '\\U0001f4a9'"},
}
func tokensEqual(ts1, ts2 tokens) bool {
if len(ts1) != len(ts2) {
return false
}
for i := range ts1 {
t1, t2 := ts1[i], ts2[i]
if t1.kind != t2.kind {
return false
}
if t1.data != t2.data {
return false
}
if t1.stringBlockIndent != t2.stringBlockIndent {
return false
}
if t1.stringBlockTermIndent != t2.stringBlockTermIndent {
return false
}
}
return true
}
func TestLex(t *testing.T) {
for _, test := range lexTests {
// Copy the test tokens and append an EOF token
testTokens := append(tokens(nil), test.tokens...)
testTokens = append(testTokens, tEOF)
tokens, err := lex(test.name, test.input)
var errString string
if err != nil {
errString = err.Error()
}
if errString != test.errString {
t.Errorf("%s: error result does not match. got\n\t%+v\nexpected\n\t%+v",
test.name, errString, test.errString)
}
if err == nil && !tokensEqual(tokens, testTokens) {
t.Errorf("%s: got\n\t%+v\nexpected\n\t%+v", test.name, tokens, testTokens)
}
}
}
// TODO: test fodder, test position reporting

95
static_error.go Normal file
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package jsonnet
import (
"fmt"
)
//////////////////////////////////////////////////////////////////////////////
// Location
// Location represents a single location in an (unspecified) file.
type Location struct {
Line int
Column int
}
// IsSet returns if this Location has been set.
func (l *Location) IsSet() bool {
return l.Line != 0
}
func (l *Location) String() string {
return fmt.Sprintf("%v:%v", l.Line, l.Column)
}
//////////////////////////////////////////////////////////////////////////////
// LocationRange
// LocationRange represents a range of a source file.
type LocationRange struct {
FileName string
Begin Location
End Location
}
// IsSet returns if this LocationRange has been set.
func (lr *LocationRange) IsSet() bool {
return lr.Begin.IsSet()
}
func (lr *LocationRange) String() string {
if !lr.IsSet() {
return lr.FileName
}
var filePrefix string
if len(lr.FileName) > 0 {
filePrefix = lr.FileName + ":"
}
if lr.Begin.Line == lr.End.Line {
if lr.Begin.Column == lr.End.Column {
return fmt.Sprintf("%s%v", filePrefix, lr.Begin.String())
}
return fmt.Sprintf("%s%v-%v", filePrefix, lr.Begin.String(), lr.End.Column)
}
return fmt.Sprintf("%s(%v)-(%v)", filePrefix, lr.Begin.String(), lr.End.String())
}
// This is useful for special locations, e.g. manifestation entry point.
func makeLocationRangeMessage(msg string) LocationRange {
return LocationRange{FileName: msg}
}
func makeLocationRange(fn string, begin Location, end Location) LocationRange {
return LocationRange{FileName: fn, Begin: begin, End: end}
}
//////////////////////////////////////////////////////////////////////////////
// StaticError
// StaticError represents an error during parsing/lexing some jsonnet.
type StaticError struct {
Loc LocationRange
Msg string
}
func makeStaticErrorMsg(msg string) StaticError {
return StaticError{Msg: msg}
}
func makeStaticErrorPoint(msg string, fn string, l Location) StaticError {
return StaticError{Msg: msg, Loc: makeLocationRange(fn, l, l)}
}
func makeStaticError(msg string, lr LocationRange) StaticError {
return StaticError{Msg: msg, Loc: lr}
}
func (err StaticError) Error() string {
loc := ""
if err.Loc.IsSet() {
loc = err.Loc.String()
}
return fmt.Sprintf("%v %v", loc, err.Msg)
}