ini

package
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Published: Dec 20, 2023 License: Apache-2.0 Imports: 10 Imported by: 0

Documentation

Overview

Package ini is an LL(1) parser for configuration files.

Example:
sections, err := ini.OpenFile("/path/to/file")
if err != nil {
	panic(err)
}

profile := "foo"
section, ok := sections.GetSection(profile)
if !ok {
	fmt.Printf("section %q could not be found", profile)
}

Below is the BNF that describes this parser

Grammar:
stmt -> section | stmt'
stmt' -> epsilon | expr
expr -> value (stmt)* | equal_expr (stmt)*
equal_expr -> value ( ':' | '=' ) equal_expr'
equal_expr' -> number | string | quoted_string
quoted_string -> " quoted_string'
quoted_string' -> string quoted_string_end
quoted_string_end -> "

section -> [ section'
section' -> section_value section_close
section_value -> number | string_subset | boolean | quoted_string_subset
quoted_string_subset -> " quoted_string_subset'
quoted_string_subset' -> string_subset quoted_string_end
quoted_string_subset -> "
section_close -> ]

value -> number | string_subset | boolean
string -> ? UTF-8 Code-Points except '\n' (U+000A) and '\r\n' (U+000D U+000A) ?
string_subset -> ? Code-points excepted by <string> grammar except ':' (U+003A), '=' (U+003D), '[' (U+005B), and ']' (U+005D) ?

SkipState will skip (NL WS)+

comment -> # comment' | ; comment'
comment' -> epsilon | value

Index

Constants

View Source
const (
	ASTKindNone = ASTKind(iota)
	ASTKindStart
	ASTKindExpr
	ASTKindEqualExpr
	ASTKindStatement
	ASTKindSkipStatement
	ASTKindExprStatement
	ASTKindSectionStatement
	ASTKindNestedSectionStatement
	ASTKindCompletedNestedSectionStatement
	ASTKindCommentStatement
	ASTKindCompletedSectionStatement
)

ASTKind* is used in the parse table to transition between the different states

View Source
const (
	TokenNone = TokenType(iota)
	TokenLit
	TokenSep
	TokenComma
	TokenOp
	TokenWS
	TokenNL
	TokenComment
)

TokenType enums

View Source
const (
	NoneType    = ValueType(iota)
	DecimalType // deprecated
	IntegerType // deprecated
	StringType
	QuotedStringType
	BoolType // deprecated
)

ValueType enums

View Source
const (
	// ErrCodeParseError is returned when a parsing error
	// has occurred.
	ErrCodeParseError = "INIParseError"
)
View Source
const (
	// ErrCodeUnableToReadFile is used when a file is failed to be
	// opened or read from.
	ErrCodeUnableToReadFile = "FailedRead"
)

Variables

View Source
var Start = newAST(ASTKindStart, AST{})

Start is used to indicate the starting state of the parse table.

Functions

func EqualExprKey

func EqualExprKey(ast AST) string

EqualExprKey will return a LHS value in the equal expr

func Walk

func Walk(tree []AST, v Visitor) error

Walk will traverse the AST using the v, the Visitor.

Types

type AST

type AST struct {
	Kind      ASTKind
	Root      Token
	RootToken bool
	Children  []AST
}

AST interface allows us to determine what kind of node we are on and casting may not need to be necessary.

The root is always the first node in Children

func ParseAST

func ParseAST(r io.Reader) ([]AST, error)

ParseAST will parse input from an io.Reader using an LL(1) parser.

func ParseASTBytes

func ParseASTBytes(b []byte) ([]AST, error)

ParseASTBytes will parse input from a byte slice using an LL(1) parser.

func (*AST) AppendChild

func (a *AST) AppendChild(child AST)

AppendChild will append to the list of children an AST has.

func (*AST) GetChildren

func (a *AST) GetChildren() []AST

GetChildren will return the current AST's list of children

func (*AST) GetRoot

func (a *AST) GetRoot() AST

GetRoot will return the root AST which can be the first entry in the children list or a token.

func (*AST) SetChildren

func (a *AST) SetChildren(children []AST)

SetChildren will set and override all children of the AST.

type ASTKind

type ASTKind int

ASTKind represents different states in the parse table and the type of AST that is being constructed

func (ASTKind) String

func (k ASTKind) String() string

type DefaultVisitor

type DefaultVisitor struct {
	Sections Sections
	// contains filtered or unexported fields
}

DefaultVisitor is used to visit statements and expressions and ensure that they are both of the correct format. In addition, upon visiting this will build sections and populate the Sections field which can be used to retrieve profile configuration.

func NewDefaultVisitor

func NewDefaultVisitor() *DefaultVisitor

NewDefaultVisitor return a DefaultVisitor

func (*DefaultVisitor) VisitExpr

func (v *DefaultVisitor) VisitExpr(expr AST) error

VisitExpr visits expressions...

func (*DefaultVisitor) VisitStatement

func (v *DefaultVisitor) VisitStatement(stmt AST) error

VisitStatement visits statements...

type ParseError

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

ParseError is an error which is returned during any part of the parsing process.

func NewParseError

func NewParseError(message string) *ParseError

NewParseError will return a new ParseError where message is the description of the error.

func (*ParseError) Code

func (err *ParseError) Code() string

Code will return the ErrCodeParseError

func (*ParseError) Error

func (err *ParseError) Error() string

func (*ParseError) Message

func (err *ParseError) Message() string

Message returns the error's message

func (*ParseError) OrigError

func (err *ParseError) OrigError() error

OrigError return nothing since there will never be any original error.

type ParseStack

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

ParseStack is a stack that contains a container, the stack portion, and the list which is the list of ASTs that have been successfully parsed.

func (*ParseStack) Len

func (s *ParseStack) Len() int

Len will return the length of the container

func (ParseStack) List

func (s ParseStack) List() []AST

List will return the completed statements

func (*ParseStack) MarkComplete

func (s *ParseStack) MarkComplete(ast AST)

MarkComplete will append the AST to the list of completed statements

func (*ParseStack) Pop

func (s *ParseStack) Pop() AST

Pop will return and truncate the last container element.

func (*ParseStack) Push

func (s *ParseStack) Push(ast AST)

Push will add the new AST to the container

func (ParseStack) String

func (s ParseStack) String() string

type ParseState

type ParseState uint

ParseState represents the current state of the parser.

const (
	InvalidState ParseState = iota
	// stmt -> value stmt'
	StatementState
	// stmt' -> MarkComplete | op stmt
	StatementPrimeState
	// value -> number | string | boolean | quoted_string
	ValueState
	// section -> [ section'
	OpenScopeState
	// section' -> value section_close
	SectionState
	// section_close -> ]
	CloseScopeState
	// SkipState will skip (NL WS)+
	SkipState
	// SkipTokenState will skip any token and push the previous
	// state onto the stack.
	SkipTokenState
	// comment -> # comment' | ; comment'
	// comment' -> MarkComplete | value
	CommentState
	// MarkComplete state will complete statements and move that
	// to the completed AST list
	MarkCompleteState
	// TerminalState signifies that the tokens have been fully parsed
	TerminalState
)

State enums for the parse table

type Section

type Section struct {
	Name string
	// contains filtered or unexported fields
}

Section contains a name and values. This represent a sectioned entry in a configuration file.

func (Section) Bool

func (t Section) Bool(k string) (bool, bool)

Bool returns a bool value at k

func (Section) Float64

func (t Section) Float64(k string) (float64, bool)

Float64 returns a float value at k

func (Section) Has

func (t Section) Has(k string) bool

Has will return whether or not an entry exists in a given section

func (Section) Int

func (t Section) Int(k string) (int64, bool)

Int returns an integer value at k

func (Section) String

func (t Section) String(k string) string

String returns the string value at k

func (Section) ValueType

func (t Section) ValueType(k string) (ValueType, bool)

ValueType will returned what type the union is set to. If k was not found, the NoneType will be returned.

type Sections

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

Sections is a map of Section structures that represent a configuration.

func OpenFile

func OpenFile(path string) (Sections, error)

OpenFile takes a path to a given file, and will open and parse that file.

func Parse

func Parse(f io.Reader) (Sections, error)

Parse will parse the given file using the shared config visitor.

func ParseBytes

func ParseBytes(b []byte) (Sections, error)

ParseBytes will parse the given bytes and return the parsed sections.

func (Sections) GetSection

func (t Sections) GetSection(p string) (Section, bool)

GetSection will return section p. If section p does not exist, false will be returned in the second parameter.

func (Sections) List

func (t Sections) List() []string

List will return a list of all sections that were successfully parsed.

type Token

type Token struct {
	ValueType ValueType
	// contains filtered or unexported fields
}

Token indicates a metadata about a given value.

func (Token) Raw

func (tok Token) Raw() []rune

Raw return the raw runes that were consumed

func (Token) Type

func (tok Token) Type() TokenType

Type returns the token type

type TokenType

type TokenType int

TokenType represents the various different tokens types

func (TokenType) String

func (t TokenType) String() string

type Value

type Value struct {
	Type ValueType
	// contains filtered or unexported fields
}

Value is a union container

func (*Value) Append

func (v *Value) Append(tok Token)

Append will append values and change the type to a string type.

func (Value) BoolValue

func (v Value) BoolValue() (bool, bool)

BoolValue returns a bool value

func (Value) FloatValue

func (v Value) FloatValue() (float64, bool)

FloatValue returns a float value

func (Value) IntValue

func (v Value) IntValue() (int64, bool)

IntValue returns an integer value

func (Value) String

func (v Value) String() string

func (Value) StringValue

func (v Value) StringValue() string

StringValue returns the string value

type ValueType

type ValueType int

ValueType is an enum that will signify what type the Value is

func (ValueType) String

func (v ValueType) String() string

type Visitor

type Visitor interface {
	VisitExpr(AST) error
	VisitStatement(AST) error
}

Visitor is an interface used by walkers that will traverse an array of ASTs.

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