iter: loop for general for-each

zeroflag · Jan 31, 2025 · 5b983b3 · 5b983b3
1 parent c8ab45d
commit 5b983b3
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Showing 7 changed files with 69 additions and 3 deletions.
diff --git a/doc/core.md b/doc/core.md
@@ -130,7 +130,7 @@ drop
 
 ### New-Style Loops
 
-Equinox is equipped with four new-style loops as well.
+Equinox is equipped with five new-style loops as well.
 
 #### To Loop
 
@@ -223,6 +223,28 @@ end
 \ k3 30
 ```
 
+#### Iter Loop
+
+The `iter` loop is a general `for-each` loop used to traverse iterators, such as the result of `gmatch`.
+
+```forth
+<iterator> iter: <name>
+  <body>
+end
+```
+
+For example:
+
+```forth
+alias: gmatch #( string.gmatch 2 )
+
+"1,2,3,4,5" "[^,]+" gmatch iter: each
+  each >num +
+end
+```
+
+The previously mentioned `pairs:` and `ipairs:` loops are special cases of this, as they automatically wrap a table into an iterator.
+
 ## Word Definition
 
 The single colon (`:`) word is used to define words, while the double colon (`::`) is used for defining words local to the specific file.

diff --git a/src/codegen.lua b/src/codegen.lua
@@ -75,9 +75,15 @@ function CodeGen:gen(ast)
         self:gen(ast.step))
   end
   if "for_each" == ast.name then
+    if ast.loop_var1 and ast.loop_var2 then
       return string.format(
         "for %s,%s in %s do",
         ast.loop_var1, ast.loop_var2, self:gen(ast.iterable))
+    else
+      return string.format(
+        "for %s in %s do",
+        ast.loop_var1, self:gen(ast.iterable))
+    end
   end
   if "pairs" == ast.name then
     return string.format("pairs(%s)", self:gen(ast.iterable))

diff --git a/src/dict.lua b/src/dict.lua
@@ -142,6 +142,7 @@ function Dict:init()
   self:def_macro("loop", "macros._loop")
   self:def_macro("ipairs:", "macros.for_ipairs")
   self:def_macro("pairs:", "macros.for_pairs")
+  self:def_macro("iter:", "macros.for_each")
   self:def_macro("to:", "macros._to")
   self:def_macro("step:", "macros._step")
   self:def_macro("#(", "macros.arity_call_lua")

diff --git a/src/equinox_bundle.lua b/src/equinox_bundle.lua
@@ -688,9 +688,15 @@ function CodeGen:gen(ast)
         self:gen(ast.step))
   end
   if "for_each" == ast.name then
+    if ast.loop_var1 and ast.loop_var2 then
       return string.format(
         "for %s,%s in %s do",
         ast.loop_var1, ast.loop_var2, self:gen(ast.iterable))
+    else
+      return string.format(
+        "for %s in %s do",
+        ast.loop_var1, self:gen(ast.iterable))
+    end
   end
   if "pairs" == ast.name then
     return string.format("pairs(%s)", self:gen(ast.iterable))
@@ -1234,6 +1240,7 @@ function Dict:init()
   self:def_macro("loop", "macros._loop")
   self:def_macro("ipairs:", "macros.for_ipairs")
   self:def_macro("pairs:", "macros.for_pairs")
+  self:def_macro("iter:", "macros.for_each")
   self:def_macro("to:", "macros._to")
   self:def_macro("step:", "macros._step")
   self:def_macro("#(", "macros.arity_call_lua")
@@ -1932,6 +1939,13 @@ function macros.for_pairs(compiler)
   return ast._foreach(var_name1, var_name2, ast._pairs(ast.pop()))
 end
 
+function macros.for_each(compiler)
+  local var_name = compiler:word()
+  compiler:new_env('ITER_LOOP')
+  compiler:def_var(var_name)
+  return ast._foreach(var_name, nil, ast.pop())
+end
+
 function macros._to(compiler)
   local loop_var = compiler:word()
   compiler:new_env('TO_LOOP')
@@ -2752,7 +2766,7 @@ return utils
 end
 end
 
-__VERSION__="0.1-25"
+__VERSION__="0.1-29"
 
 local Compiler = require("compiler")
 local Optimizer = require("ast_optimizer")

diff --git a/src/macros.lua b/src/macros.lua
@@ -476,6 +476,13 @@ function macros.for_pairs(compiler)
   return ast._foreach(var_name1, var_name2, ast._pairs(ast.pop()))
 end
 
+function macros.for_each(compiler)
+  local var_name = compiler:word()
+  compiler:new_env('ITER_LOOP')
+  compiler:def_var(var_name)
+  return ast._foreach(var_name, nil, ast.pop())
+end
+
 function macros._to(compiler)
   local loop_var = compiler:word()
   compiler:new_env('TO_LOOP')

diff --git a/src/version/version.txt b/src/version/version.txt
@@ -1 +1 @@
-0.1-25
+0.1-29
diff --git a/tests/test_for_iter.eqx b/tests/test_for_iter.eqx
@@ -0,0 +1,16 @@
+depth 0 =assert
+adepth 0 =assert
+
+alias: gmatch #( string.gmatch 2 )
+
+0
+"1,2,3,4,5" "[^,]+" gmatch iter: each
+  each >num +
+end
+
+dup . cr
+
+15 =assert
+
+depth 0 =assert
+adepth 0 =assert