comparison win32-mingw/include/capnp/schema.capnp @ 50:37d53a7e8262

Headers for KJ/Capnp Win32

+# Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
+# Licensed under the MIT License:
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+using Cxx = import "/capnp/c++.capnp";
+
+@0xa93fc509624c72d9;
+$Cxx.namespace("capnp::schema");
+
+using Id = UInt64;
+# The globally-unique ID of a file, type, or annotation.
+
+struct Node {
+  id @0 :Id;
+
+  displayName @1 :Text;
+  # Name to present to humans to identify this Node.  You should not attempt to parse this.  Its
+  # format could change.  It is not guaranteed to be unique.
+  #
+  # (On Zooko's triangle, this is the node's nickname.)
+
+  displayNamePrefixLength @2 :UInt32;
+  # If you want a shorter version of `displayName` (just naming this node, without its surrounding
+  # scope), chop off this many characters from the beginning of `displayName`.
+
+  scopeId @3 :Id;
+  # ID of the lexical parent node.  Typically, the scope node will have a NestedNode pointing back
+  # at this node, but robust code should avoid relying on this (and, in fact, group nodes are not
+  # listed in the outer struct's nestedNodes, since they are listed in the fields).  `scopeId` is
+  # zero if the node has no parent, which is normally only the case with files, but should be
+  # allowed for any kind of node (in order to make runtime type generation easier).
+
+  parameters @32 :List(Parameter);
+  # If this node is parameterized (generic), the list of parameters. Empty for non-generic types.
+
+  isGeneric @33 :Bool;
+  # True if this node is generic, meaning that it or one of its parent scopes has a non-empty
+  # `parameters`.
+
+  struct Parameter {
+    # Information about one of the node's parameters.
+
+    name @0 :Text;
+  }
+
+  nestedNodes @4 :List(NestedNode);
+  # List of nodes nested within this node, along with the names under which they were declared.
+
+  struct NestedNode {
+    name @0 :Text;
+    # Unqualified symbol name.  Unlike Node.displayName, this *can* be used programmatically.
+    #
+    # (On Zooko's triangle, this is the node's petname according to its parent scope.)
+
+    id @1 :Id;
+    # ID of the nested node.  Typically, the target node's scopeId points back to this node, but
+    # robust code should avoid relying on this.
+  }
+
+  annotations @5 :List(Annotation);
+  # Annotations applied to this node.
+
+  union {
+    # Info specific to each kind of node.
+
+    file @6 :Void;
+
+    struct :group {
+      dataWordCount @7 :UInt16;
+      # Size of the data section, in words.
+
+      pointerCount @8 :UInt16;
+      # Size of the pointer section, in pointers (which are one word each).
+
+      preferredListEncoding @9 :ElementSize;
+      # The preferred element size to use when encoding a list of this struct.  If this is anything
+      # other than `inlineComposite` then the struct is one word or less in size and is a candidate
+      # for list packing optimization.
+
+      isGroup @10 :Bool;
+      # If true, then this "struct" node is actually not an independent node, but merely represents
+      # some named union or group within a particular parent struct.  This node's scopeId refers
+      # to the parent struct, which may itself be a union/group in yet another struct.
+      #
+      # All group nodes share the same dataWordCount and pointerCount as the top-level
+      # struct, and their fields live in the same ordinal and offset spaces as all other fields in
+      # the struct.
+      #
+      # Note that a named union is considered a special kind of group -- in fact, a named union
+      # is exactly equivalent to a group that contains nothing but an unnamed union.
+
+      discriminantCount @11 :UInt16;
+      # Number of fields in this struct which are members of an anonymous union, and thus may
+      # overlap.  If this is non-zero, then a 16-bit discriminant is present indicating which
+      # of the overlapping fields is active.  This can never be 1 -- if it is non-zero, it must be
+      # two or more.
+      #
+      # Note that the fields of an unnamed union are considered fields of the scope containing the
+      # union -- an unnamed union is not its own group.  So, a top-level struct may contain a
+      # non-zero discriminant count.  Named unions, on the other hand, are equivalent to groups
+      # containing unnamed unions.  So, a named union has its own independent schema node, with
+      # `isGroup` = true.
+
+      discriminantOffset @12 :UInt32;
+      # If `discriminantCount` is non-zero, this is the offset of the union discriminant, in
+      # multiples of 16 bits.
+
+      fields @13 :List(Field);
+      # Fields defined within this scope (either the struct's top-level fields, or the fields of
+      # a particular group; see `isGroup`).
+      #
+      # The fields are sorted by ordinal number, but note that because groups share the same
+      # ordinal space, the field's index in this list is not necessarily exactly its ordinal.
+      # On the other hand, the field's position in this list does remain the same even as the
+      # protocol evolves, since it is not possible to insert or remove an earlier ordinal.
+      # Therefore, for most use cases, if you want to identify a field by number, it may make the
+      # most sense to use the field's index in this list rather than its ordinal.
+    }
+
+    enum :group {
+      enumerants@14 :List(Enumerant);
+      # Enumerants ordered by numeric value (ordinal).
+    }
+
+    interface :group {
+      methods @15 :List(Method);
+      # Methods ordered by ordinal.
+
+      superclasses @31 :List(Superclass);
+      # Superclasses of this interface.
+    }
+
+    const :group {
+      type @16 :Type;
+      value @17 :Value;
+    }
+
+    annotation :group {
+      type @18 :Type;
+
+      targetsFile @19 :Bool;
+      targetsConst @20 :Bool;
+      targetsEnum @21 :Bool;
+      targetsEnumerant @22 :Bool;
+      targetsStruct @23 :Bool;
+      targetsField @24 :Bool;
+      targetsUnion @25 :Bool;
+      targetsGroup @26 :Bool;
+      targetsInterface @27 :Bool;
+      targetsMethod @28 :Bool;
+      targetsParam @29 :Bool;
+      targetsAnnotation @30 :Bool;
+    }
+  }
+}
+
+struct Field {
+  # Schema for a field of a struct.
+
+  name @0 :Text;
+
+  codeOrder @1 :UInt16;
+  # Indicates where this member appeared in the code, relative to other members.
+  # Code ordering may have semantic relevance -- programmers tend to place related fields
+  # together.  So, using code ordering makes sense in human-readable formats where ordering is
+  # otherwise irrelevant, like JSON.  The values of codeOrder are tightly-packed, so the maximum
+  # value is count(members) - 1.  Fields that are members of a union are only ordered relative to
+  # the other members of that union, so the maximum value there is count(union.members).
+
+  annotations @2 :List(Annotation);
+
+  const noDiscriminant :UInt16 = 0xffff;
+
+  discriminantValue @3 :UInt16 = Field.noDiscriminant;
+  # If the field is in a union, this is the value which the union's discriminant should take when
+  # the field is active.  If the field is not in a union, this is 0xffff.
+
+  union {
+    slot :group {
+      # A regular, non-group, non-fixed-list field.
+
+      offset @4 :UInt32;
+      # Offset, in units of the field's size, from the beginning of the section in which the field
+      # resides.  E.g. for a UInt32 field, multiply this by 4 to get the byte offset from the
+      # beginning of the data section.
+
+      type @5 :Type;
+      defaultValue @6 :Value;
+
+      hadExplicitDefault @10 :Bool;
+      # Whether the default value was specified explicitly.  Non-explicit default values are always
+      # zero or empty values.  Usually, whether the default value was explicit shouldn't matter.
+      # The main use case for this flag is for structs representing method parameters:
+      # explicitly-defaulted parameters may be allowed to be omitted when calling the method.
+    }
+
+    group :group {
+      # A group.
+
+      typeId @7 :Id;
+      # The ID of the group's node.
+    }
+  }
+
+  ordinal :union {
+    implicit @8 :Void;
+    explicit @9 :UInt16;
+    # The original ordinal number given to the field.  You probably should NOT use this; if you need
+    # a numeric identifier for a field, use its position within the field array for its scope.
+    # The ordinal is given here mainly just so that the original schema text can be reproduced given
+    # the compiled version -- i.e. so that `capnp compile -ocapnp` can do its job.
+  }
+}
+
+struct Enumerant {
+  # Schema for member of an enum.
+
+  name @0 :Text;
+
+  codeOrder @1 :UInt16;
+  # Specifies order in which the enumerants were declared in the code.
+  # Like Struct.Field.codeOrder.
+
+  annotations @2 :List(Annotation);
+}
+
+struct Superclass {
+  id @0 :Id;
+  brand @1 :Brand;
+}
+
+struct Method {
+  # Schema for method of an interface.
+
+  name @0 :Text;
+
+  codeOrder @1 :UInt16;
+  # Specifies order in which the methods were declared in the code.
+  # Like Struct.Field.codeOrder.
+
+  implicitParameters @7 :List(Node.Parameter);
+  # The parameters listed in [] (typically, type / generic parameters), whose bindings are intended
+  # to be inferred rather than specified explicitly, although not all languages support this.
+
+  paramStructType @2 :Id;
+  # ID of the parameter struct type.  If a named parameter list was specified in the method
+  # declaration (rather than a single struct parameter type) then a corresponding struct type is
+  # auto-generated.  Such an auto-generated type will not be listed in the interface's
+  # `nestedNodes` and its `scopeId` will be zero -- it is completely detached from the namespace.
+  # (Awkwardly, it does of course inherit generic parameters from the method's scope, which makes
+  # this a situation where you can't just climb the scope chain to find where a particular
+  # generic parameter was introduced. Making the `scopeId` zero was a mistake.)
+
+  paramBrand @5 :Brand;
+  # Brand of param struct type.
+
+  resultStructType @3 :Id;
+  # ID of the return struct type; similar to `paramStructType`.
+
+  resultBrand @6 :Brand;
+  # Brand of result struct type.
+
+  annotations @4 :List(Annotation);
+}
+
+struct Type {
+  # Represents a type expression.
+
+  union {
+    # The ordinals intentionally match those of Value.
+
+    void @0 :Void;
+    bool @1 :Void;
+    int8 @2 :Void;
+    int16 @3 :Void;
+    int32 @4 :Void;
+    int64 @5 :Void;
+    uint8 @6 :Void;
+    uint16 @7 :Void;
+    uint32 @8 :Void;
+    uint64 @9 :Void;
+    float32 @10 :Void;
+    float64 @11 :Void;
+    text @12 :Void;
+    data @13 :Void;
+
+    list :group {
+      elementType @14 :Type;
+    }
+
+    enum :group {
+      typeId @15 :Id;
+      brand @21 :Brand;
+    }
+    struct :group {
+      typeId @16 :Id;
+      brand @22 :Brand;
+    }
+    interface :group {
+      typeId @17 :Id;
+      brand @23 :Brand;
+    }
+
+    anyPointer :union {
+      unconstrained :union {
+        # A regular AnyPointer.
+        #
+        # The name "unconstained" means as opposed to constraining it to match a type parameter.
+        # In retrospect this name is probably a poor choice given that it may still be constrained
+        # to be a struct, list, or capability.
+
+        anyKind @18 :Void;       # truly AnyPointer
+        struct @25 :Void;        # AnyStruct
+        list @26 :Void;          # AnyList
+        capability @27 :Void;    # Capability
+      }
+
+      parameter :group {
+        # This is actually a reference to a type parameter defined within this scope.
+
+        scopeId @19 :Id;
+        # ID of the generic type whose parameter we're referencing. This should be a parent of the
+        # current scope.
+
+        parameterIndex @20 :UInt16;
+        # Index of the parameter within the generic type's parameter list.
+      }
+
+      implicitMethodParameter :group {
+        # This is actually a reference to an implicit (generic) parameter of a method. The only
+        # legal context for this type to appear is inside Method.paramBrand or Method.resultBrand.
+
+        parameterIndex @24 :UInt16;
+      }
+    }
+  }
+}
+
+struct Brand {
+  # Specifies bindings for parameters of generics. Since these bindings turn a generic into a
+  # non-generic, we call it the "brand".
+
+  scopes @0 :List(Scope);
+  # For each of the target type and each of its parent scopes, a parameterization may be included
+  # in this list. If no parameterization is included for a particular relevant scope, then either
+  # that scope has no parameters or all parameters should be considered to be `AnyPointer`.
+
+  struct Scope {
+    scopeId @0 :Id;
+    # ID of the scope to which these params apply.
+
+    union {
+      bind @1 :List(Binding);
+      # List of parameter bindings.
+
+      inherit @2 :Void;
+      # The place where this Brand appears is actually within this scope or a sub-scope,
+      # and the bindings for this scope should be inherited from the reference point.
+    }
+  }
+
+  struct Binding {
+    union {
+      unbound @0 :Void;
+      type @1 :Type;
+
+      # TODO(someday): Allow non-type parameters? Unsure if useful.
+    }
+  }
+}
+
+struct Value {
+  # Represents a value, e.g. a field default value, constant value, or annotation value.
+
+  union {
+    # The ordinals intentionally match those of Type.
+
+    void @0 :Void;
+    bool @1 :Bool;
+    int8 @2 :Int8;
+    int16 @3 :Int16;
+    int32 @4 :Int32;
+    int64 @5 :Int64;
+    uint8 @6 :UInt8;
+    uint16 @7 :UInt16;
+    uint32 @8 :UInt32;
+    uint64 @9 :UInt64;
+    float32 @10 :Float32;
+    float64 @11 :Float64;
+    text @12 :Text;
+    data @13 :Data;
+
+    list @14 :AnyPointer;
+
+    enum @15 :UInt16;
+    struct @16 :AnyPointer;
+
+    interface @17 :Void;
+    # The only interface value that can be represented statically is "null", whose methods always
+    # throw exceptions.
+
+    anyPointer @18 :AnyPointer;
+  }
+}
+
+struct Annotation {
+  # Describes an annotation applied to a declaration.  Note AnnotationNode describes the
+  # annotation's declaration, while this describes a use of the annotation.
+
+  id @0 :Id;
+  # ID of the annotation node.
+
+  brand @2 :Brand;
+  # Brand of the annotation.
+  #
+  # Note that the annotation itself is not allowed to be parameterized, but its scope might be.
+
+  value @1 :Value;
+}
+
+enum ElementSize {
+  # Possible element sizes for encoded lists.  These correspond exactly to the possible values of
+  # the 3-bit element size component of a list pointer.
+
+  empty @0;    # aka "void", but that's a keyword.
+  bit @1;
+  byte @2;
+  twoBytes @3;
+  fourBytes @4;
+  eightBytes @5;
+  pointer @6;
+  inlineComposite @7;
+}
+
+struct CodeGeneratorRequest {
+  nodes @0 :List(Node);
+  # All nodes parsed by the compiler, including for the files on the command line and their
+  # imports.
+
+  requestedFiles @1 :List(RequestedFile);
+  # Files which were listed on the command line.
+
+  struct RequestedFile {
+    id @0 :Id;
+    # ID of the file.
+
+    filename @1 :Text;
+    # Name of the file as it appeared on the command-line (minus the src-prefix).  You may use
+    # this to decide where to write the output.
+
+    imports @2 :List(Import);
+    # List of all imported paths seen in this file.
+
+    struct Import {
+      id @0 :Id;
+      # ID of the imported file.
+
+      name @1 :Text;
+      # Name which *this* file used to refer to the foreign file.  This may be a relative name.
+      # This information is provided because it might be useful for code generation, e.g. to
+      # generate #include directives in C++.  We don't put this in Node.file because this
+      # information is only meaningful at compile time anyway.
+      #
+      # (On Zooko's triangle, this is the import's petname according to the importing file.)
+    }
+  }
+}