Added syntax for skip_to and buffer.

buffer tells fiddle to create a buffer of a number of bytes.

skip_to tells fiddle to skip to some new offset. It's essentially an
unnamed buffer

1 files changed, 39 insertions, 0 deletions

diff --git a/src/Language/Fiddle/Compiler/ConsistencyCheck.hs b/src/Language/Fiddle/Compiler/ConsistencyCheck.hs
index 00a53dc..c34007f 100644
--- a/src/Language/Fiddle/Compiler/ConsistencyCheck.hs
+++ b/src/Language/Fiddle/Compiler/ConsistencyCheck.hs
@@ -15,6 +15,7 @@ import Data.Functor.Identity
 import qualified Data.IntMap as IntMap
 import Data.List (intercalate)
 import qualified Data.List.NonEmpty as NonEmpty
+import qualified Data.Text as Text
 import Data.Typeable
 import GHC.TypeError as TypeError
 import Language.Fiddle.Ast
@@ -155,6 +156,44 @@ advanceObjTypeBody (ObjTypeBody us decls a) startOffset = do
                     assertedPos <- expressionToIntM expr
                     checkPositionAssertion (annot e) assertedPos offset
                     return (ret, offset)
+                  (SkipToStatement _ qmeta expr ann) -> do
+                    let pos = trueValue expr
+                        sz = if pos < offset then 0 else pos - offset
+                        span = Present (FieldSpan offset sz)
+                        qmeta' = fmap (\q -> q {regSpan = span}) qmeta
+
+                        szExpr = ConstExpression (LeftV sz) (annot expr)
+                     in do
+                          if pos < offset
+                            then do
+                              emitDiagnosticError "Skip to backwards" ann
+                              return (ret, offset)
+                            else
+                              if sz == 0
+                                then
+                                  return (ret, offset)
+                                else do
+                                  doReturn
+                                    ( BufferDecl
+                                        qmeta'
+                                        ( Guaranteed
+                                            ( Identifier
+                                                ( Text.pack $
+                                                    basenamePart (regFullPath (unwrap qmeta'))
+                                                )
+                                                a
+                                            )
+                                        )
+                                        szExpr
+                                        ann
+                                    )
+                                    sz
+                  (BufferDecl qmeta (Guaranteed ident) sz a) -> do
+                    sz' <- advanceStage () sz
+                    let size = trueValue sz'
+                        span = Present (FieldSpan offset size)
+                        qmeta' = fmap (\q -> q {regSpan = span}) qmeta
+                    doReturn (BufferDecl qmeta' (Guaranteed ident) sz' a) size
                   (RegisterDecl qmeta mod ident size Nothing a) -> do
                     let declaredSize = regSzToBits (getLeft size)
                     reifiedSizeBytes <- checkBitsSizeMod8 a declaredSize