Initial commit

1 files changed, 74 insertions, 0 deletions

diff --git a/src/scope.lua b/src/scope.lua
new file mode 100644
index 0000000..dd19392
--- /dev/null
+++ b/src/scope.lua
@@ -0,0 +1,74 @@
+--[[
+This module implements functions that handle scoping rules 
+]]
+local scope = {}
+
+function scope.lineno (s, i)
+  if i == 1 then return 1, 1 end
+  local l, lastline = 0, ""
+  s = s:sub(1, i) .. "\n"
+  for line in s:gmatch("[^\n]*[\n]") do
+    l = l + 1
+    lastline = line
+  end
+  local c = lastline:len() - 1
+  return l, c ~= 0 and c or 1
+end
+
+function scope.new_scope (env)
+  if not env.scope then
+    env.scope = 0
+  else
+    env.scope = env.scope + 1
+  end
+  local scope = env.scope
+  env.maxscope = scope
+  env[scope] = {}
+  env[scope]["label"] = {}
+  env[scope]["local"] = {}
+  env[scope]["goto"] = {}
+end
+
+function scope.begin_scope (env)
+  env.scope = env.scope + 1
+end
+
+function scope.end_scope (env)
+  env.scope = env.scope - 1
+end
+
+function scope.new_function (env)
+  if not env.fscope then
+    env.fscope = 0
+  else
+    env.fscope = env.fscope + 1
+  end
+  local fscope = env.fscope
+  env["function"][fscope] = {}
+end
+
+function scope.begin_function (env)
+  env.fscope = env.fscope + 1
+end
+
+function scope.end_function (env)
+  env.fscope = env.fscope - 1
+end
+
+function scope.begin_loop (env)
+  if not env.loop then
+    env.loop = 1
+  else
+    env.loop = env.loop + 1
+  end
+end
+
+function scope.end_loop (env)
+  env.loop = env.loop - 1
+end
+
+function scope.insideloop (env)
+  return env.loop and env.loop > 0
+end
+
+return scope