////////////////////////////////////////////////////////////
//~ Error types

Struct(M_Error)
{
  M_Error *next;
  String msg;
  struct M_Token *token;
};

Struct(M_ErrorList)
{
  M_Error *first;
  M_Error *last;
  u64 count;
};

////////////////////////////////////////////////////////////
//~ File types

Struct(M_File)
{
  String name;
  String data;
};

////////////////////////////////////////////////////////////
//~ Token types

Enum(M_TokenKind)
{
  M_TokenKind_Ident,
  M_TokenKind_Eol,  // End of line
};

Struct(M_Token)
{
  b32 valid;
  M_Token *next;

  M_TokenKind kind;
  struct M_TokenFile *file;

  String s;
};

Struct(M_TokenFile)
{
  b32 valid;
  M_TokenFile *next;

  String name;
  String data;

  M_Token *first_token;
  M_Token *last_token;
  u64 tokens_count;

  M_ErrorList errors;
};

Struct(M_TokenFileList)
{
  M_TokenFile *first;
  M_TokenFile *last;
  u64 count;
};

////////////////////////////////////////////////////////////
//~ Entry types

Enum(M_EntryKind)
{
  M_EntryKind_Unknown,
  M_EntryKind_Layer,
  M_EntryKind_Dep,
  M_EntryKind_IncludeC,
  M_EntryKind_IncludeG,
  M_EntryKind_DefaultDownstream,
  M_EntryKind_Bootstrap,
  M_EntryKind_VertexShader,
  M_EntryKind_PixelShader,
  M_EntryKind_ComputeShader,
  M_EntryKind_EmbedDir,
};

Enum(M_PlatformKind)
{
  M_PlatformKind_Any,
  M_PlatformKind_Win32,
};

Global Readonly char *M_entry_kind_rules[] = {
  [M_EntryKind_Layer]                      = "@Layer",
  [M_EntryKind_Dep]                        = "@Dep",
  [M_EntryKind_IncludeC]                   = "@IncludeC",
  [M_EntryKind_IncludeG]                   = "@IncludeG",
  [M_EntryKind_DefaultDownstream]          = "@DefaultDownstream",
  [M_EntryKind_Bootstrap]                  = "@Bootstrap",
  [M_EntryKind_VertexShader]               = "@VertexShader",
  [M_EntryKind_PixelShader]                = "@PixelShader",
  [M_EntryKind_ComputeShader]              = "@ComputeShader",
  [M_EntryKind_EmbedDir]                   = "@EmbedDir",
};

Struct(M_Entry)
{
  b32 valid;
  M_Entry *next;

  M_EntryKind kind;
  M_Token *name_token;

  M_Token *arg_tokens[2];
  u64 args_count;
};

Struct(M_Layer)
{
  b32 valid;
  M_Layer *next;

  M_TokenFile *file;

  M_Entry *first;
  M_Entry *last;
  u64 count;
  M_ErrorList errors;
};

Struct(M_LayerList)
{
  M_Layer *first;
  M_Layer *last;
  u64 count;
};

////////////////////////////////////////////////////////////
//~ State types

extern Readonly M_Token M_NilToken;
extern Readonly M_TokenFile M_NilTokenFile;
extern Readonly M_Entry M_NilEntry;
extern Readonly M_Layer M_NilLayer;

////////////////////////////////////////////////////////////
//~ Error helpers

M_Error *M_PushError(Arena *arena, M_ErrorList *l, M_Token *token, String msg);
void M_AppendErrors(Arena *arena, M_ErrorList *dst, M_ErrorList src);

////////////////////////////////////////////////////////////
//~ Lex

M_Token *M_PushToken(Arena *arena, M_TokenFile *file, String s, M_TokenKind kind);
M_TokenFileList M_TokensFromSrcDirs(Arena *arena, StringList src_dirs);

////////////////////////////////////////////////////////////
//~ Parse

M_Layer *M_PushLayer(Arena *arena, M_LayerList *list, M_TokenFile *file);
M_Entry *M_PushEntry(Arena *arena, M_Layer *l, M_EntryKind kind, M_Token *entry_token, u64 args_count, M_Token **args);
M_LayerList M_LayersFromTokenFiles(Arena *arena, M_TokenFileList token_files);

////////////////////////////////////////////////////////////
//~ Flatten

M_Layer M_FlattenEntries(Arena *arena, M_LayerList unflattened, StringList starting_layer_names);