Merge branch 'master' of ssh://git.eclipse.org/gitroot/koneki/org.eclipse.koneki...

[metalua.git] / src / lib / metalua / extension / continue.mlua

diff --git a/src/lib/metalua/extension/continue.mlua b/src/lib/metalua/extension/continue.mlua
deleted file mode 100644 (file)
index 2bb2ad9..0000000
--- a/src/lib/metalua/extension/continue.mlua
+++ /dev/null
@@ -1,53 +0,0 @@
-require "metalua.walk"
-
-----------------------------------------------------------------------
--- * [loop_tags] are the tags of statements which support continue.
--- * [loop_keywords] are the initial keywords which trigger the parsing
---   of these statements: they're indeed indexed by keyword in [mlp.stat].
-----------------------------------------------------------------------
-
-local loop_tags = table.transpose{ "Forin", "Fornum", "While", "Repeat" }
-local loop_keywords = { "for", "while", "repeat" }
-
-----------------------------------------------------------------------
--- This function takes the AST of a continue-enabled loop, parse
--- its body to find all instances of [`Continue]. If any of them
--- is found ([label~=nil]), they're transformed in [`Goto{...}], and
--- the corresponding label is added at the end of the loop's body.
---
--- Caveat: if a [continue] appears in the non-body part of a loop
--- (and therefore is relative to some enclosing loop), it isn't
--- handled, and therefore causes a compilation error. This could
--- only happen due in a [`Stat{ }], however, since [`Function{ }]
--- cuts the search for [`Continue].
-----------------------------------------------------------------------
-local function loop_transformer (ast)
-   local label
-   local cfg = { stat = { }; expr = { } }
-
-   function cfg.stat.down (x)
-      if loop_tags[x.tag] then return 'break'
-      elseif x.tag=='Continue' then
-         if not label then label = mlp.gensym 'continue' end
-         x <- `Goto{ label }
-      end
-   end
-
-   function cfg.expr.down (x)
-      return x.tag=='Function' and 'break'
-   end
-
-   local loop_body = ast.tag=="Repeat" and ast[1] or ast[#ast]
-   walk.block (cfg, loop_body)
-   if label then table.insert (loop_body, `Label{ label }) end
-end
-
-----------------------------------------------------------------------
--- Register the transformer for each kind of loop:
-----------------------------------------------------------------------
-for keyword in values (loop_keywords) do
-   mlp.stat:get(keyword).transformers:add (loop_transformer)
-end
-
-mlp.lexer:add "continue"
-mlp.stat:add{ "continue", builder = ||`Continue }