This change performs typechecking during binding. This is less about typechecking per se -- since higher level languages will have presumably given us well-typed IL -- and more about preparing the AST so that we can evaluate the fully bound nodes to produce a MuGL graph. It also serves as a "verifier" for the incoming MuIL, however. This is clearly incomplete, as the dozens of TODOs will make obvious. But it's a clean checkpoint that does enough interesting typechecking that I am landing it now.
186 lines
6.8 KiB
Go
186 lines
6.8 KiB
Go
// Copyright 2016 Marapongo, Inc. All rights reserved.
|
|
|
|
// This package contains the core MuIL symbol and token types.
|
|
package tokens
|
|
|
|
import (
|
|
"strings"
|
|
|
|
"github.com/marapongo/mu/pkg/util/contract"
|
|
)
|
|
|
|
// Token is a qualified name that is capable of resolving to a symbol entirely on its own. Most uses of tokens are
|
|
// typed based on the context, so that a subset of the token syntax is permissable (see the various typedefs below).
|
|
// However, in its full generality, a token can have a package part, a module part, a module-member part, and a
|
|
// class-member part. Obviously tokens that are meant to address just a module won't have the module-member part, and
|
|
// tokens addressing module members won't have the class-member part, etc.
|
|
//
|
|
// Token's grammar is as follows:
|
|
//
|
|
// Token = <Name> |
|
|
// = <PackageName> [ ":" <ModuleName> [ "/" <ModuleMemberName> [ "." <ClassMemberName> ] ] ]
|
|
// PackageName = <QName>
|
|
// ModuleName = <QName>
|
|
// ModuleMemberName = <Name>
|
|
// ClassMemberName = <Name>
|
|
//
|
|
// A token may be a simple name in the case that it refers to a built-in symbol, like a primitive type, or when it
|
|
// refers to an identifier that is in scope, rather than a symbol that is to be bound through package/module resolution.
|
|
//
|
|
// Notice that both package and module names may be qualified names (meaning they can have "/" delimiters; see QName's
|
|
// comments), and that module and class members must use unqualified, simple names (meaning they have no delimiters).
|
|
// The specialized token kinds differ only in what elements they require as part of the token string.
|
|
type Token string
|
|
|
|
const ModuleDelimiter string = ":" // the character following a package (before a module).
|
|
const ModuleMemberDelimiter string = "/" // the character following a module (before a module member).
|
|
const ClassMemberDelimiter string = "." // the character following a class name (before a class member).
|
|
|
|
// Package is a token representing just a package. It uses a much simpler grammar:
|
|
// Package = <PackageName>
|
|
// Note that a package name of "." means "current package", to simplify emission and lookups.
|
|
type Package Token
|
|
|
|
// PackageName is a qualified name referring to an imported package.
|
|
type PackageName QName
|
|
|
|
func (tok Package) Name() PackageName {
|
|
return PackageName(tok)
|
|
}
|
|
|
|
// Module is a token representing a module. It uses the following subset of the token grammar:
|
|
// Module = <Package> ":" <ModuleName>
|
|
// Note that a module name of "." means "current module", to simplify emission and lookups.
|
|
type Module Token
|
|
|
|
// ModuleName is a qualified name referring to an imported module from a package.
|
|
type ModuleName QName
|
|
|
|
func (tok Module) Package() Package {
|
|
ix := strings.LastIndex(string(tok), ModuleDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return Package(string(tok)[:ix])
|
|
}
|
|
|
|
func (tok Module) Name() ModuleName {
|
|
ix := strings.LastIndex(string(tok), ModuleDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return ModuleName(string(tok)[ix+1:])
|
|
}
|
|
|
|
// ModuleMember is a token representing a module's member. It uses the following grammar. Note that this is not
|
|
// ambiguous because member names cannot contain slashes, and so the "last" slash in a name delimits the member:
|
|
// ModuleMember = <Module> "/" <ModuleMemberName>
|
|
type ModuleMember Token
|
|
|
|
// ModuleMemberName is a simple name representing the module member's identifier.
|
|
type ModuleMemberName Name
|
|
|
|
func (tok ModuleMember) Package() Package {
|
|
return tok.Module().Package()
|
|
}
|
|
|
|
func (tok ModuleMember) Module() Module {
|
|
ix := strings.LastIndex(string(tok), ModuleMemberDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return Module(string(tok)[:ix])
|
|
}
|
|
|
|
func (tok ModuleMember) Name() ModuleMemberName {
|
|
ix := strings.LastIndex(string(tok), ModuleMemberDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return ModuleMemberName(string(tok)[ix+1:])
|
|
}
|
|
|
|
// ClassMember is a token representing a class's member. It uses the following grammar. Unlike ModuleMember, this
|
|
// cannot use a slash for delimiting names, because we use often ClassMember and ModuleMember interchangably:
|
|
// ClassMember = <ModuleMember> "." <ClassMemberName>
|
|
type ClassMember Token
|
|
|
|
// ClassMemberName is a simple name representing the class member's identifier.
|
|
type ClassMemberName Name
|
|
|
|
func (tok ClassMember) Package() Package {
|
|
return tok.Module().Package()
|
|
}
|
|
|
|
func (tok ClassMember) Module() Module {
|
|
return tok.Class().Module()
|
|
}
|
|
|
|
func (tok ClassMember) Class() Type {
|
|
ix := strings.LastIndex(string(tok), ClassMemberDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return Type(string(tok)[:ix])
|
|
}
|
|
|
|
func (tok ClassMember) Name() ClassMemberName {
|
|
ix := strings.LastIndex(string(tok), ClassMemberDelimiter)
|
|
contract.Assert(ix != -1)
|
|
return ClassMemberName(string(tok)[ix+1:])
|
|
}
|
|
|
|
// Type is a token representing a type. It is either a primitive type name, or a reference to a module class:
|
|
// Type = <Name> | <ModuleMember>
|
|
type Type Token
|
|
|
|
// TypeName is a simple name representing the type's name, without any package/module qualifiers.
|
|
type TypeName Name
|
|
|
|
func (tok Type) Package() Package {
|
|
if tok.Primitive() {
|
|
return Package("")
|
|
} else {
|
|
return ClassMember(tok).Package()
|
|
}
|
|
}
|
|
|
|
func (tok Type) Module() Module {
|
|
if tok.Primitive() {
|
|
return Module("")
|
|
} else {
|
|
return ClassMember(tok).Module()
|
|
}
|
|
}
|
|
|
|
func (tok Type) Name() TypeName {
|
|
if tok.Primitive() {
|
|
contract.Assert(IsName(string(tok)))
|
|
return TypeName(tok)
|
|
} else {
|
|
return TypeName(ClassMember(tok).Name())
|
|
}
|
|
}
|
|
|
|
func (tok Type) Member() ModuleMember {
|
|
return ModuleMember(tok)
|
|
}
|
|
|
|
// Primitive indicates whether this type is a primitive type name (i.e., not qualified with a module, etc).
|
|
func (tok Type) Primitive() bool {
|
|
return strings.LastIndex(string(tok), ModuleMemberDelimiter) == -1
|
|
}
|
|
|
|
// Variable is a token representing a variable (module property, class property, or local variable (including
|
|
// parameters)). It can be a simple name for the local cases, or a true token for others:
|
|
// Variable = <Name> | <ModuleMember> | <ClassMember>
|
|
type Variable Token
|
|
|
|
// Function is a token representing a variable (module method or class method). Its grammar is as follows:
|
|
// Variable = <ModuleMember> | <ClassMember>
|
|
type Function Token
|
|
|
|
// NewModuleToken produces a new qualified token from a parent package and the module.
|
|
func NewModuleToken(parent Package, name ModuleName) Module {
|
|
return Module(string(parent) + ModuleDelimiter + string(name))
|
|
}
|
|
|
|
// NewModuleMemberToken produces a new qualified token from a parent module and the member's identifier.
|
|
func NewModuleMemberToken(parent Module, name ModuleMemberName) ModuleMember {
|
|
return ModuleMember(string(parent) + ModuleMemberDelimiter + string(name))
|
|
}
|
|
|
|
// NewClassMemberToken produces a new qualified token from a parent class and the class's identifier.
|
|
func NewClassMemberToken(parent ModuleMember, name ClassMemberName) ClassMember {
|
|
return ClassMember(string(parent) + ClassMemberDelimiter + string(name))
|
|
}
|