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-rw-r--r--src/ast_opts.lua251
1 files changed, 151 insertions, 100 deletions
diff --git a/src/ast_opts.lua b/src/ast_opts.lua
index de49932..060c0ac 100644
--- a/src/ast_opts.lua
+++ b/src/ast_opts.lua
@@ -1,100 +1,151 @@
---[[
- Optimizatoins for abstract syntax trees
-]]
-local msg = io.write
---A debugging function, a replacement for glua PrintTable
-local function printtable(tbl, tabset)
- tabset = tabset or 0
- for k,v in pairs(tbl) do
- for i = 0,tabset do msg("\t") end
- msg(k .. ":")
- if type(v) == "table" then
- msg("\n")
- printtable(v, tabset + 1)
- else
- msg(tostring(v) .. "\n")
- end
- end
-end
-
---A function to see if two ast's are equal-ish (does not compare position)
-local function deepcompare(tbl1, tbl2)
- if type(tbl1) ~= type(tbl2) then return false end
- for k,v in pairs(tbl1) do
- print("Checking ", k, " from tbl1")
- if k == "pos" then goto cont end
- if type(v) == "table" then
- print("It is a table! going deeper")
- if not deepcompare(v,tbl2[k]) then
- return false
- end
- else
- print("Checking ", v , " against ", tbl2[k])
- if v ~= tbl2[k] then
- return false
- end
- end
- ::cont::
- end
- return true
-end
-
-local opts = {}
-
---Optimization 1
---Folds things with an operator when the fold results in a smaller string
-local foldables = {
- ["add"] = function(a,b) return a + b end,
- ["mul"] = function(a,b) return a * b end,
- ["mod"] = function(a,b) return a % b end,
- ["sub"] = function(a,b) return a - b end,
- --["div"] = function(a,b) return a / b end, division has the chance to give us really long strings!
-}
-opts[1] = function(ast)
- if ast.tag ~= "Op" then return false end
- local opname = ast[1]
- local func = foldables[opname]
- if ast[3] ~= nil and func ~= nil and ast[2].tag == "Number" and ast[3].tag == "Number" then
- ast.tag = "Number"
- ast[1] = func(ast[2][1],ast[3][1])
- for i = 2,#ast do
- ast[i] = nil
- end
- return true
- end
- return false
-end
-
---Optimization 2
---Find places where we can replace calls with invokes.
-opts[2] = function(ast)
- if ast.tag == "Call" and ast.pos == 160 then
- print("Ast:")
- printtable(ast)
- print("ast[1][1]")
- printtable(ast[1][1])
- print("ast[2]")
- printtable(ast[2])
- local dcr = deepcompare(ast[1][1],ast[2])
- print("Deepcompare:",dcr)
- --error("stopping")
- end
- if ast.tag == "Call" and deepcompare(ast[1][1][1], ast[2][1]) then
- print("Before correcting for invoke, ast is")
- printtable(ast)
- for i = 2,#ast[2] do
- ast[i] = ast[i+1]
- end
- ast.tag = "Invoke"
- ast[2] = ast[1][2]
- ast[1] = ast[1][1]
- print("After correcting for invoke, ast is")
- printtable(ast)
-
- --error("Call that should be invoke detected")
- return true
- end
-
-end
-
-return opts
+--[[
+ Optimizatoins for abstract syntax trees
+]]
+local msg = io.write
+
+--A debugging function, a replacement for glua PrintTable
+local function printtable(tbl, tabset)
+ tabset = tabset or 0
+ for k,v in pairs(tbl) do
+ for i = 0,tabset do msg("\t") end
+ msg(k .. ":")
+ if type(v) == "table" then
+ msg("\n")
+ printtable(v, tabset + 1)
+ else
+ msg(tostring(v) .. "\n")
+ end
+ end
+end
+
+--A function to see if two tables are equal-ish
+local function deepcompare(tbl1, tbl2)
+ if type(tbl1) ~= type(tbl2) then return false end
+ for k,v in pairs(tbl1) do
+ print("Checking ", k, " from tbl1")
+ if k == "pos" then goto cont end
+ if type(v) == "table" then
+ print("It is a table! going deeper")
+ if not deepcompare(v,tbl2[k]) then
+ return false
+ end
+ else
+ print("Checking ", v , " against ", tbl2[k])
+ if v ~= tbl2[k] then
+ return false
+ end
+ end
+ ::cont::
+ end
+ return true
+end
+
+--Makes sure 2 things are refrenceing the same index
+local function indexcompare(tbl1,tbl2)
+ if type(tbl1) ~= "table" or type(tbl2) ~= "table" then return false end
+ --print("indexcompare is checking ",tbl1,tbl2)
+ --printtable(tbl1)
+ --print("is the same as")
+ --printtable(tbl2)
+ if tbl1.tag == "Id" and tbl2.tag == "Id" then
+ return tbl1[1] == tbl2[1]
+ elseif tbl1.tag == "Index" and tbl2.tag == "Index" then
+ return indexcompare(tbl1[1],tbl2[1]) and indexcompare(tbl1[2],tbl2[2])
+ elseif tbl1.tag == "String" and tbl2.tag == "String" then
+ return tbl1[1] == tbl2[1]
+ else
+ return false
+ end
+end
+
+local opts = {}
+
+--Optimization 1
+--Folds things with an operator when we have numbers on both sides, and the fold results in a smaller string
+local foldables = {
+ ["add"] = function(a,b) return a + b end,
+ ["mul"] = function(a,b) return a * b end,
+ ["mod"] = function(a,b) return a % b end,
+ ["sub"] = function(a,b) return a - b end,
+ --["div"] = function(a,b) return a / b end,-- division has the chance to give us really long strings!
+}
+opts[1] = function(ast)
+ if ast.tag ~= "Op" then return false end
+ local opname = ast[1]
+ local func = foldables[opname]
+ if ast[3] ~= nil and func ~= nil and ast[2].tag == "Number" and ast[3].tag == "Number" then
+ ast.tag = "Number"
+ ast[1] = func(ast[2][1],ast[3][1])
+ for i = 2,#ast do
+ ast[i] = nil
+ end
+ return true
+ end
+ return false
+end
+
+--Optimization 2
+--Find places where we can replace calls with invokes.
+--Lua provides syntax sugar where
+-- table.method(table,arg1,arg2,...)
+--is the same as
+-- table:method(arg1,arg2,...)
+opts[2] = function(ast)
+ --[[for debugging
+ if ast.tag == "Call" then
+ --print("Ast:")
+ --printtable(ast)
+ --print("ast[1][1]")
+ --printtable(ast[1][1])
+ --print("ast[2]")
+ --printtable(ast[2])
+ --local dcr = indexcompare(ast[1][1],ast[2])
+ --print("indexcompare:",dcr)
+ --error("stopping")
+ end
+ ]]
+
+ --The ands are to make sure we short circut before indexing a nil
+ if ast.tag == "Call" and ast[1][1] and ast[2] and indexcompare(ast[1][1][1], ast[2][1]) then
+ --print("Before correcting for invoke, ast is")
+ --printtable(ast)
+ for i = 2,#ast[2] do
+ ast[i] = ast[i + 1]
+ end
+ ast.tag = "Invoke"
+ ast[2] = ast[1][2]
+ ast[1] = ast[1][1]
+
+ return true
+ end
+ return false
+end
+
+--Find places where we have multiple variables declared, but not initalized
+--and turn it into a 1-liner
+--so local a local b local c
+--becomes
+--local a,b,c
+--TODO: This can be done faster and in 1 pass with a little extra complexity
+opts[3] = function(ast)
+ if ast.tag == "Block" then
+ for i = 1,#ast do
+ if ast[i].tag == "Local" and next(ast[i][2]) == nil then
+ local cursor = ast[i]
+ local r
+ i = i + 1
+ while ast[i].tag == "Local" and next(ast[i][2]) == nil do
+ table.insert(cursor[1],ast[i][1][1])
+ table.remove(ast,i)
+ i = i + 1
+ r = true
+ end
+ if r then return true end
+ end
+ end
+ return false
+ end
+ return false
+end
+
+return opts
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2026-01-18 04:42:12 +0000