X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flib%2Fmetalua%2Fextension%2Fanaphoric.mlua;fp=src%2Flib%2Fmetalua%2Fextension%2Fanaphoric.mlua;h=0000000000000000000000000000000000000000;hb=355ff0bc201e00856ba20d82c65b14ffa6fcfe4b;hp=2439fed481babb16de517352ddf7d26a4598be72;hpb=f998820846d157a0c28abfb71cfca4b273f45eb9;p=metalua.git

diff --git a/src/lib/metalua/extension/anaphoric.mlua b/src/lib/metalua/extension/anaphoric.mlua
deleted file mode 100644
index 2439fed..0000000
--- a/src/lib/metalua/extension/anaphoric.mlua
+++ /dev/null
@@ -1,54 +0,0 @@
---------------------------------------------------------------------------------
---
--- Anaphoric macros.
---
--- This extension turns 'it' into a special variable, that's bound to
--- an often used value:
---
--- * in an 'if' statement, 'it' is bound, in a block, to the condition
---   that triggered the block's execution:
---   > if 1234 then y=it end; assert (y == 1234)
---
--- * in a while loop, it's bound to the test:
---   > while file:read "*a" do table.insert (lines, it) end
---
--- 'it' is bound the the most closely surrounding structure. If you wanted to
--- use its content at a deeper position in the AST, you would have to save it
--- in a temporary variable. But what you should really do in such a case is
--- avoiding to use anaphoric macros: they're fine for one-liner, but they
--- reduce readability for bigger functions.
---------------------------------------------------------------------------------
-
--- TODO: 'and' operator could, and maybe should, be anaphoric as well
--- TODO: anaphoric functions would be cool for recursive functions, but
---       recursive calls are always in an 'if' statement, so the pronoun
---       used for functions must not be the same as for 'if'.
-
-require 'freevars'
-
-local function anaphoric_if(ast)
-   local it_found = false
-   for i=2, #ast do 
-      if freevars.block(ast[i])['it'] then
-         it_found = true
-         break
-      end
-   end
-   if it_found then
-      local cond = ast[1]
-      ast[1] = +{it}
-      return +{stat: do local it = -{cond}; -{ast} end }
-   end
-end
-
-local function anaphoric_while(ast)
-   local it_found = false
-   if freevars.block(ast[2])['it'] then
-      local cond = ast[1]
-      ast[1] = +{it}
-      return +{stat: do local it = -{cond}; -{ast} end }
-   end
-end
-
-mlp.stat:get'if'.transformers:add(anaphoric_if)
-mlp.stat:get'while'.transformers:add(anaphoric_while)
\ No newline at end of file