core

package
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 Go to latest Published: Nov 28, 2025 License: MIT Imports: 7 Imported by: 0

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Constants

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Variables

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Functions

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Types

type Array 

type Array []Object

Array represents a PDF array

func (Array) Get 

func (a Array) Get(index int) Object

Get retrieves an element at the given index

func (Array) GetInt 

func (a Array) GetInt(index int) (Int, bool)

GetInt retrieves an integer at the given index

func (Array) GetName 

func (a Array) GetName(index int) (Name, bool)

GetName retrieves a name at the given index

func (Array) GetReal 

func (a Array) GetReal(index int) (Real, bool)

GetReal retrieves a real number at the given index

func (Array) Len 

func (a Array) Len() int

Len returns the length of the array

func (Array) String 

func (a Array) String() string

func (Array) Type 

func (a Array) Type() ObjectType

type Bool 

type Bool bool

Bool represents a PDF boolean

func (Bool) String 

func (b Bool) String() string

func (Bool) Type 

func (b Bool) Type() ObjectType

type Dict 

type Dict map[string]Object

Dict represents a PDF dictionary

func (Dict) Delete 

func (d Dict) Delete(key string)

Delete removes a key from the dictionary

func (Dict) Get 

func (d Dict) Get(key string) Object

Get retrieves a value from the dictionary

func (Dict) GetArray 

func (d Dict) GetArray(key string) (Array, bool)

GetArray retrieves an array value

func (Dict) GetBool 

func (d Dict) GetBool(key string) (Bool, bool)

GetBool retrieves a boolean value

func (Dict) GetDict 

func (d Dict) GetDict(key string) (Dict, bool)

GetDict retrieves a dictionary value

func (Dict) GetIndirectRef 

func (d Dict) GetIndirectRef(key string) (IndirectRef, bool)

GetIndirectRef retrieves an indirect reference

func (Dict) GetInt 

func (d Dict) GetInt(key string) (Int, bool)

GetInt retrieves an integer value

func (Dict) GetName 

func (d Dict) GetName(key string) (Name, bool)

GetName retrieves a name value

func (Dict) GetReal 

func (d Dict) GetReal(key string) (Real, bool)

GetReal retrieves a real number value

func (Dict) GetStream 

func (d Dict) GetStream(key string) (*Stream, bool)

GetStream retrieves a stream value

func (Dict) GetString 

func (d Dict) GetString(key string) (String, bool)

GetString retrieves a string value

func (Dict) Has 

func (d Dict) Has(key string) bool

Has checks if a key exists in the dictionary

func (Dict) Keys 

func (d Dict) Keys() []string

Keys returns all keys in the dictionary

func (Dict) Set 

func (d Dict) Set(key string, value Object)

Set sets a value in the dictionary

func (Dict) String 

func (d Dict) String() string

func (Dict) Type 

func (d Dict) Type() ObjectType

type IndirectObject 

type IndirectObject struct {
	Ref    IndirectRef
	Object Object
}

IndirectObject represents an indirect object with its reference

type IndirectRef 

type IndirectRef struct {
	Number     int
	Generation int
}

IndirectRef represents an indirect object reference

func (IndirectRef) String 

func (r IndirectRef) String() string

func (IndirectRef) Type 

func (r IndirectRef) Type() ObjectType

type Int 

type Int int64

Int represents a PDF integer

func (Int) String 

func (i Int) String() string

func (Int) Type 

func (i Int) Type() ObjectType

type Lexer 

type Lexer struct {
	// contains filtered or unexported fields
}

Lexer performs lexical analysis of PDF content

func NewLexer 

func NewLexer(r io.Reader) *Lexer

NewLexer creates a new lexer

func (*Lexer) NextToken 

func (l *Lexer) NextToken() (*Token, error)

NextToken returns the next token from the input

func (*Lexer) Peek 

func (l *Lexer) Peek() (byte, error)

Peek returns the next byte without consuming it (public wrapper for peek)

func (*Lexer) ReadByte 

func (l *Lexer) ReadByte() (byte, error)

ReadByte reads and returns a single byte (public wrapper for readByte)

func (*Lexer) ReadBytes 

func (l *Lexer) ReadBytes(n int) ([]byte, error)

ReadBytes reads exactly n bytes from the underlying reader This is used for reading binary stream data

func (*Lexer) SkipBytes 

func (l *Lexer) SkipBytes(n int) error

SkipBytes skips exactly n bytes from the underlying reader

type Name 

type Name string

Name represents a PDF name

func (Name) String 

func (n Name) String() string

func (Name) Type 

func (n Name) Type() ObjectType

type Null 

type Null struct{}

Null represents a PDF null object

func (Null) String 

func (n Null) String() string

func (Null) Type 

func (n Null) Type() ObjectType

type Object 

type Object interface {
	Type() ObjectType
	String() string
}

Object represents a PDF object

type ObjectStream 

type ObjectStream struct {
	// contains filtered or unexported fields
}

ObjectStream represents a PDF Object Stream (Type /ObjStm) Object streams (PDF 1.5+) store multiple objects in a single compressed stream

func NewObjectStream 

func NewObjectStream(stream *Stream) (*ObjectStream, error)

NewObjectStream creates an ObjectStream from a Stream object Returns an error if the stream is not a valid object stream

func (*ObjectStream) ContainsObject 

func (os *ObjectStream) ContainsObject(objNum int) (bool, error)

ContainsObject checks if an object number is stored in this stream

func (*ObjectStream) Extends 

func (os *ObjectStream) Extends() *IndirectRef

Extends returns the reference to another object stream this one extends, or nil

func (*ObjectStream) First 

func (os *ObjectStream) First() int

First returns the byte offset to the first object in the decoded data

func (*ObjectStream) GetObjectByIndex 

func (os *ObjectStream) GetObjectByIndex(index int) (Object, int, error)

GetObjectByIndex extracts an object by its index within the stream (0-based) The index corresponds to the position in the header, not the object number

func (*ObjectStream) GetObjectByNumber 

func (os *ObjectStream) GetObjectByNumber(objNum int) (Object, int, error)

GetObjectByNumber finds and extracts an object by its object number Returns the object and its index, or an error if not found

func (*ObjectStream) N 

func (os *ObjectStream) N() int

N returns the number of objects in the stream

func (*ObjectStream) ObjectNumbers 

func (os *ObjectStream) ObjectNumbers() ([]int, error)

ObjectNumbers returns a slice of all object numbers stored in this stream

type ObjectType 

type ObjectType int

ObjectType represents the type of PDF object 

const (
	ObjNull ObjectType = iota
	ObjBool
	ObjInt
	ObjReal
	ObjString
	ObjName
	ObjArray
	ObjDict
	ObjStream
	ObjIndirect
)

func (ObjectType) String 

func (t ObjectType) String() string

String returns the string representation of the object type

type Parser 

type Parser struct {
	// contains filtered or unexported fields
}

Parser parses PDF objects using the Lexer

func NewParser 

func NewParser(r io.Reader) *Parser

NewParser creates a new PDF parser

func (*Parser) ParseIndirectObject 

func (p *Parser) ParseIndirectObject() (*IndirectObject, error)

ParseIndirectObject parses an indirect object (num gen obj ... endobj)

func (*Parser) ParseObject 

func (p *Parser) ParseObject() (Object, error)

ParseObject parses a PDF object

type Real 

type Real float64

Real represents a PDF real number

func (Real) String 

func (r Real) String() string

func (Real) Type 

func (r Real) Type() ObjectType

type Stream 

type Stream struct {
	Dict Dict
	Data []byte
	// contains filtered or unexported fields
}

Stream represents a PDF stream object

func (*Stream) Decode 

func (s *Stream) Decode() ([]byte, error)

Decode decodes the stream data according to its Filter(s) Returns decoded data or error

func (*Stream) Decoded 

func (s *Stream) Decoded() ([]byte, error)

Decoded returns the decoded stream data

func (*Stream) String 

func (s *Stream) String() string

func (*Stream) Type 

func (s *Stream) Type() ObjectType

type String 

type String string

String represents a PDF string

func (String) String 

func (s String) String() string

func (String) Type 

func (s String) Type() ObjectType

type Token 

type Token struct {
	Type  TokenType
	Value []byte
	Pos   int64 // Position in stream
}

Token represents a lexical token

type TokenType 

type TokenType int

TokenType represents the type of token 

const (
	TokenEOF TokenType = iota
	TokenWhitespace
	TokenComment
	TokenKeyword     // true, false, null, obj, endobj, stream, endstream, etc.
	TokenInteger     // 123
	TokenReal        // 3.14
	TokenString      // (hello)
	TokenHexString   // <48656C6C6F>
	TokenName        // /Type
	TokenArrayStart  // [
	TokenArrayEnd    // ]
	TokenDictStart   // <<
	TokenDictEnd     // >>
	TokenIndirectRef // R (after two numbers)
)

type XRefEntry 

type XRefEntry struct {
	Type       XRefEntryType // Entry type (free, uncompressed, or compressed)
	Offset     int64         // Byte offset (uncompressed) or object stream number (compressed)
	Generation int           // Generation number (uncompressed) or index within object stream (compressed)
	InUse      bool          // true if object is in use (Type != XRefEntryFree)
}

XRefEntry represents a single cross-reference table entry

type XRefEntryType 

type XRefEntryType int

XRefEntryType represents the type of an XRef entry 

const (
	// XRefEntryFree indicates a free (deleted) object entry
	XRefEntryFree XRefEntryType = 0
	// XRefEntryUncompressed indicates an in-use object at a byte offset in the file
	XRefEntryUncompressed XRefEntryType = 1
	// XRefEntryCompressed indicates an object stored in an object stream (PDF 1.5+)
	XRefEntryCompressed XRefEntryType = 2
)

func (XRefEntryType) String 

func (t XRefEntryType) String() string

String returns a human-readable representation of the entry type

type XRefParser 

type XRefParser struct {
	// contains filtered or unexported fields
}

XRefParser parses PDF cross-reference tables

func NewXRefParser 

func NewXRefParser(r io.ReadSeeker) *XRefParser

NewXRefParser creates a new XRef parser

func (*XRefParser) FindXRef 

func (x *XRefParser) FindXRef() (int64, error)

FindXRef finds the byte offset of the XRef table by scanning from EOF PDFs end with "startxref\n<offset>\n%%EOF"

func (*XRefParser) ParseAllXRefs 

func (x *XRefParser) ParseAllXRefs() ([]*XRefTable, error)

ParseAllXRefs parses the main XRef table and all previous ones (incremental updates) Returns them in order from oldest to newest

func (*XRefParser) ParsePrevXRef 

func (x *XRefParser) ParsePrevXRef(table *XRefTable) (*XRefTable, error)

ParsePrevXRef checks if the trailer has a /Prev entry and parses that XRef table This handles incremental updates in PDFs

func (*XRefParser) ParseXRef 

func (x *XRefParser) ParseXRef(offset int64) (*XRefTable, error)

ParseXRef parses the XRef table at the given byte offset Handles both traditional XRef tables (PDF 1.0-1.4) and XRef streams (PDF 1.5+)

func (*XRefParser) ParseXRefFromEOF 

func (x *XRefParser) ParseXRefFromEOF() (*XRefTable, error)

ParseXRefFromEOF finds and parses the XRef table by scanning from EOF

type XRefTable 

type XRefTable struct {
	Entries  map[int]*XRefEntry // Map from object number to XRef entry
	Trailer  Dict               // Trailer dictionary
	IsStream bool               // true if this XRef came from a stream (PDF 1.5+)
}

XRefTable represents a PDF cross-reference table

func MergeXRefTables 

func MergeXRefTables(tables ...*XRefTable) *XRefTable

MergeXRefTables merges multiple XRef tables (from incremental updates) Later entries override earlier ones

func NewXRefTable 

func NewXRefTable() *XRefTable

NewXRefTable creates a new empty XRef table

func (*XRefTable) Get 

func (x *XRefTable) Get(objNum int) (*XRefEntry, bool)

Get retrieves an XRef entry by object number

func (*XRefTable) Set 

func (x *XRefTable) Set(objNum int, entry *XRefEntry)

Set adds or updates an XRef entry

func (*XRefTable) Size 

func (x *XRefTable) Size() int

Size returns the number of entries in the table

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