package entity

import "fmt"
import "git.tebibyte.media/fspl/fspl/errors"

// LiteralInt specifies an integer value. It can be assigned to any type that is
// derived from an integer or a float, as long as the value fo the literal can
// fit within the range of the type. It cannot be directly assigned to an
// interface because it contains no inherent type information. A value cast may
// be used for this purpose.
type LiteralInt struct {
	// Syntax
	Position errors.Position
	Value int

	// Semantics
	Ty Type
}
func (*LiteralInt) expression(){}
func (this *LiteralInt) Type () Type { return this.Ty }
func (this *LiteralInt) String () string {
	return fmt.Sprint(this.Value)
}

// LiteralFloat specifies a floating point value. It can be assigned to any type
// that is derived from a float. It cannot be directly assigned to an interface
// because it contains no inherent type information. A value cast may be used
// for this purpose.
type LiteralFloat struct {
	// Syntax
	Position errors.Position
	Value float64

	// Semantics
	Ty Type
}
func (*LiteralFloat) expression(){}
func (this *LiteralFloat) Type () Type { return this.Ty }
func (this *LiteralFloat) String () string {
	return fmt.Sprint(this.Value)
}

// LiteralString specifies a string value. It takes on different data
// representations depending on what the base type of what it is assigned to is
// structurally equivalent to:
//   - Integer: Single unicode code point. When assigning to an integer, the
//     string literal may not be longer than one code point, and that code point
//     must fit in the integer.
//   - Slice of 8 bit integers: UTF-8 string.
//   - Slice of 16 bit integers: UTF-16 string.
//   - Slice of 32 bit (or larger) integers: UTF-32 string.
//   - Array of integers: The same as slices of integers, but the string literal
//     must fit inside of the array.
//   - Pointer to 8 bit integer: Null-terminated UTF-8 string (AKA C-string).
// A string literal cannot be directly assigned to an interface because it
// contains no inherent type information. A value cast may be used for this
// purpose.
type LiteralString struct {
	// Syntax
	Position   errors.Position
	ValueUTF8  string
	ValueUTF16 []uint16
	ValueUTF32 []rune

	// Semantics
	Ty Type
}
func (*LiteralString) expression(){}
func (this *LiteralString) Type () Type { return this.Ty }
func (this *LiteralString) String () string {
	return Quote(this.ValueUTF8)
}

// LiteralArray is a composite array literal. It can contain any number of
// values. It can be assigned to any array type that:
//   1. has an identical length, and
//   2. who's element type can be assigned to by all the element values in the
//      literal.
// It cannot be directly assigned to an interface because it contains no
// inherent type information. A value cast may be used for this purpose.
type LiteralArray struct {
	// Syntax
	Position errors.Position
	Elements []Expression

	// Semantics
	Ty Type
}
func (*LiteralArray) expression(){}
func (this *LiteralArray) Type () Type { return this.Ty }
func (this *LiteralArray) String () string {
	out := "(*"
	for _, element := range this.Elements {
		out += fmt.Sprint(" ", element)
	}
	return out + ")"
}

// LiteralStruct is a composite structure literal. It can contain any number of
// name:value pairs. It can be assigned to any struct type that:
//   1. has at least the members specified in the literal
//   2. who's member types can be assigned to by the corresponding member
//      values in the literal.
// It cannot be directly assigned to an interface because it contains no
// inherent type information. A value cast may be used for this purpose.
type LiteralStruct struct {
	// Syntax
	Position errors.Position
	Members  []*Member

	// Semantics
	Ty Type
	MemberOrder []string
	MemberMap map[string] *Member
}
func (*LiteralStruct) expression(){}
func (this *LiteralStruct) Type () Type { return this.Ty }
func (this *LiteralStruct) String () string {
	out := "(."
	for _, member := range this.Members {
		out += fmt.Sprint(" ", member)
	}
	return out + ")"
}

// LiteralBoolean is a boolean literal. It may be either true or false. It can
// be assigned to any type derived from a boolean. It cannot be directly
// assigned to an interface because it contains no inherent type information. A
// value cast may be used for this purpose.
type LiteralBoolean struct {
	// Syntax
	Position errors.Position
	Value    bool

	// Semantics
	Ty Type
}
func (*LiteralBoolean) expression(){}
func (this *LiteralBoolean) Type () Type { return this.Ty }
func (this *LiteralBoolean) String () string {
	if this.Value {
		return "true"
	} else {
		return "false"
	}
}

type LiteralNil struct {
	// Syntax
	Position errors.Position
	
	// Semantics
	Ty Type
}
func (*LiteralNil) expression(){}
func (this *LiteralNil) Type () Type { return this.Ty }
func (this *LiteralNil) String () string { return "nil" }