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author | Corey Hulen <corey@hulen.com> | 2017-03-24 23:31:34 -0700 |
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committer | enahum <nahumhbl@gmail.com> | 2017-03-25 03:31:34 -0300 |
commit | 54d3d47daf9190275bbdaf8703b84969a4593451 (patch) | |
tree | 05899b296d0186c1a0da8a540bc486e34ad8eec9 /vendor/github.com/hashicorp/hcl/json/parser/parser.go | |
parent | 7460302dec7796e01c98264e84bece8169cb6ed9 (diff) | |
download | chat-54d3d47daf9190275bbdaf8703b84969a4593451.tar.gz chat-54d3d47daf9190275bbdaf8703b84969a4593451.tar.bz2 chat-54d3d47daf9190275bbdaf8703b84969a4593451.zip |
PLT-6076 Adding viper libs for config file changes (#5871)
* Adding viper libs for config file changes
* Removing the old fsnotify lib
* updating some missing libs
Diffstat (limited to 'vendor/github.com/hashicorp/hcl/json/parser/parser.go')
-rw-r--r-- | vendor/github.com/hashicorp/hcl/json/parser/parser.go | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/hcl/json/parser/parser.go b/vendor/github.com/hashicorp/hcl/json/parser/parser.go new file mode 100644 index 000000000..6f4608530 --- /dev/null +++ b/vendor/github.com/hashicorp/hcl/json/parser/parser.go @@ -0,0 +1,313 @@ +package parser + +import ( + "errors" + "fmt" + + "github.com/hashicorp/hcl/hcl/ast" + hcltoken "github.com/hashicorp/hcl/hcl/token" + "github.com/hashicorp/hcl/json/scanner" + "github.com/hashicorp/hcl/json/token" +) + +type Parser struct { + sc *scanner.Scanner + + // Last read token + tok token.Token + commaPrev token.Token + + enableTrace bool + indent int + n int // buffer size (max = 1) +} + +func newParser(src []byte) *Parser { + return &Parser{ + sc: scanner.New(src), + } +} + +// Parse returns the fully parsed source and returns the abstract syntax tree. +func Parse(src []byte) (*ast.File, error) { + p := newParser(src) + return p.Parse() +} + +var errEofToken = errors.New("EOF token found") + +// Parse returns the fully parsed source and returns the abstract syntax tree. +func (p *Parser) Parse() (*ast.File, error) { + f := &ast.File{} + var err, scerr error + p.sc.Error = func(pos token.Pos, msg string) { + scerr = fmt.Errorf("%s: %s", pos, msg) + } + + // The root must be an object in JSON + object, err := p.object() + if scerr != nil { + return nil, scerr + } + if err != nil { + return nil, err + } + + // We make our final node an object list so it is more HCL compatible + f.Node = object.List + + // Flatten it, which finds patterns and turns them into more HCL-like + // AST trees. + flattenObjects(f.Node) + + return f, nil +} + +func (p *Parser) objectList() (*ast.ObjectList, error) { + defer un(trace(p, "ParseObjectList")) + node := &ast.ObjectList{} + + for { + n, err := p.objectItem() + if err == errEofToken { + break // we are finished + } + + // we don't return a nil node, because might want to use already + // collected items. + if err != nil { + return node, err + } + + node.Add(n) + + // Check for a followup comma. If it isn't a comma, then we're done + if tok := p.scan(); tok.Type != token.COMMA { + break + } + } + + return node, nil +} + +// objectItem parses a single object item +func (p *Parser) objectItem() (*ast.ObjectItem, error) { + defer un(trace(p, "ParseObjectItem")) + + keys, err := p.objectKey() + if err != nil { + return nil, err + } + + o := &ast.ObjectItem{ + Keys: keys, + } + + switch p.tok.Type { + case token.COLON: + pos := p.tok.Pos + o.Assign = hcltoken.Pos{ + Filename: pos.Filename, + Offset: pos.Offset, + Line: pos.Line, + Column: pos.Column, + } + + o.Val, err = p.objectValue() + if err != nil { + return nil, err + } + } + + return o, nil +} + +// objectKey parses an object key and returns a ObjectKey AST +func (p *Parser) objectKey() ([]*ast.ObjectKey, error) { + keyCount := 0 + keys := make([]*ast.ObjectKey, 0) + + for { + tok := p.scan() + switch tok.Type { + case token.EOF: + return nil, errEofToken + case token.STRING: + keyCount++ + keys = append(keys, &ast.ObjectKey{ + Token: p.tok.HCLToken(), + }) + case token.COLON: + // If we have a zero keycount it means that we never got + // an object key, i.e. `{ :`. This is a syntax error. + if keyCount == 0 { + return nil, fmt.Errorf("expected: STRING got: %s", p.tok.Type) + } + + // Done + return keys, nil + case token.ILLEGAL: + fmt.Println("illegal") + default: + return nil, fmt.Errorf("expected: STRING got: %s", p.tok.Type) + } + } +} + +// object parses any type of object, such as number, bool, string, object or +// list. +func (p *Parser) objectValue() (ast.Node, error) { + defer un(trace(p, "ParseObjectValue")) + tok := p.scan() + + switch tok.Type { + case token.NUMBER, token.FLOAT, token.BOOL, token.NULL, token.STRING: + return p.literalType() + case token.LBRACE: + return p.objectType() + case token.LBRACK: + return p.listType() + case token.EOF: + return nil, errEofToken + } + + return nil, fmt.Errorf("Expected object value, got unknown token: %+v", tok) +} + +// object parses any type of object, such as number, bool, string, object or +// list. +func (p *Parser) object() (*ast.ObjectType, error) { + defer un(trace(p, "ParseType")) + tok := p.scan() + + switch tok.Type { + case token.LBRACE: + return p.objectType() + case token.EOF: + return nil, errEofToken + } + + return nil, fmt.Errorf("Expected object, got unknown token: %+v", tok) +} + +// objectType parses an object type and returns a ObjectType AST +func (p *Parser) objectType() (*ast.ObjectType, error) { + defer un(trace(p, "ParseObjectType")) + + // we assume that the currently scanned token is a LBRACE + o := &ast.ObjectType{} + + l, err := p.objectList() + + // if we hit RBRACE, we are good to go (means we parsed all Items), if it's + // not a RBRACE, it's an syntax error and we just return it. + if err != nil && p.tok.Type != token.RBRACE { + return nil, err + } + + o.List = l + return o, nil +} + +// listType parses a list type and returns a ListType AST +func (p *Parser) listType() (*ast.ListType, error) { + defer un(trace(p, "ParseListType")) + + // we assume that the currently scanned token is a LBRACK + l := &ast.ListType{} + + for { + tok := p.scan() + switch tok.Type { + case token.NUMBER, token.FLOAT, token.STRING: + node, err := p.literalType() + if err != nil { + return nil, err + } + + l.Add(node) + case token.COMMA: + continue + case token.LBRACE: + node, err := p.objectType() + if err != nil { + return nil, err + } + + l.Add(node) + case token.BOOL: + // TODO(arslan) should we support? not supported by HCL yet + case token.LBRACK: + // TODO(arslan) should we support nested lists? Even though it's + // written in README of HCL, it's not a part of the grammar + // (not defined in parse.y) + case token.RBRACK: + // finished + return l, nil + default: + return nil, fmt.Errorf("unexpected token while parsing list: %s", tok.Type) + } + + } +} + +// literalType parses a literal type and returns a LiteralType AST +func (p *Parser) literalType() (*ast.LiteralType, error) { + defer un(trace(p, "ParseLiteral")) + + return &ast.LiteralType{ + Token: p.tok.HCLToken(), + }, nil +} + +// scan returns the next token from the underlying scanner. If a token has +// been unscanned then read that instead. +func (p *Parser) scan() token.Token { + // If we have a token on the buffer, then return it. + if p.n != 0 { + p.n = 0 + return p.tok + } + + p.tok = p.sc.Scan() + return p.tok +} + +// unscan pushes the previously read token back onto the buffer. +func (p *Parser) unscan() { + p.n = 1 +} + +// ---------------------------------------------------------------------------- +// Parsing support + +func (p *Parser) printTrace(a ...interface{}) { + if !p.enableTrace { + return + } + + const dots = ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " + const n = len(dots) + fmt.Printf("%5d:%3d: ", p.tok.Pos.Line, p.tok.Pos.Column) + + i := 2 * p.indent + for i > n { + fmt.Print(dots) + i -= n + } + // i <= n + fmt.Print(dots[0:i]) + fmt.Println(a...) +} + +func trace(p *Parser, msg string) *Parser { + p.printTrace(msg, "(") + p.indent++ + return p +} + +// Usage pattern: defer un(trace(p, "...")) +func un(p *Parser) { + p.indent-- + p.printTrace(")") +} |