Work in progress...

1 files changed, 133 insertions, 0 deletions

diff --git a/lua_obj.moon b/lua_obj.moon
new file mode 100644
index 0000000..ba2d0bb
--- /dev/null
+++ b/lua_obj.moon
@@ -0,0 +1,133 @@
+{:insert, :remove, :concat} = table
+immutable = require 'immutable'
+local Lua, LuaValue, Location
+
+Location = immutable {"text_name","text","start","stop"}, {
+    __new: (text_name, text, start, stop)-> text_name, text, start, stop or start
+    __tostring: "#{text_name}[#{start}:#{stop}]"
+    __lt: (other)=>
+        assert(@text == other.text, "Cannot compare sources from different texts")
+        return if @start == other.start
+            @stop < other.stop
+        else @start < other.start
+    __le: (other)=>
+        assert(@text == other.text, "Cannot compare sources from different texts")
+        return if @start == other.start
+            @stop <= other.stop
+        else @start <= other.start
+    get_text: => @text\sub(@start,@stop)
+    get_line_number: =>
+        -- TODO: do a binary search if this is actually slow, which I doubt
+        line_starts = LINE_STARTS[@text]
+        start_line = 1
+        while start_line < #line_starts and line_starts[start_line+1] <= @start
+            start_line += 1
+        stop_line = start_line
+        while stop_line < #line_starts and line_starts[stop_line+1] <= @stop
+            stop_line += 1
+        return start_line, stop_line
+    get_line: => "#{@text_name}:#{@get_line_number}"
+    get_line_range: =>
+        start_line, stop_line = @get_line_number
+        return if stop_line == start_line
+            "#{text_name}:#{start_line}"
+        else "#{text_name}:#{start_line}-#{stop_line}"
+}
+
+class Lua
+    is_statement: true
+    is_value: false
+
+    __new: (@source, ...)=>
+        @bits = {...}
+        @free_vars = {}
+    
+    add_free_vars: (free_vars)=>
+        seen = {[v]:true for v in *@free_vars}
+        for var in *free_vars
+            unless seen[var]
+                @free_vars[#@free_vars+1] = var
+                seen[var] = true
+
+    as_statements: => self
+
+    declare_locals: (skip={})=>
+        if next(skip) == 1
+            skip = {[s]:true for s in *skip}
+        @prepend "local #{concat @free_vars, ", "};\n"
+        for var in *@free_vars do skip[var] = true
+        for bit in *@bits
+            if type(bit) == Lua
+                bit\declare_locals(skip)
+
+    __tostring: =>
+        buff = {}
+        for b in *@bits
+            if type(b) == 'string'
+                buff[#buff+1] = b
+            else
+                for sub in *b\render!
+                    buff[#buff+1] = sub
+        return concat(buff, "")
+
+    __len: =>
+        len = 0
+        for b in *@bits
+            len += #b
+        return len
+    
+    append: (...)=>
+        n = select("#",...)
+        bits = @bits
+        for i=1,n
+            bits[#bits+1] = select(i, ...)
+    
+    prepend: (...)=>
+        n = select("#",...)
+        bits = @bits
+        for i=#bits+n,n+1,-1
+            bits[i] = bits[i-n]
+        for i=1,n
+            bits[i] = select(i, ...)
+
+    make_offset_table: (lua_chunkname)=>
+        -- Return a mapping from output (lua) character number to input (nomsu) character number
+        lua_str = tostring(self)
+        metadata = {
+            nomsu_filename:@source.text_name, nomsu_file:@source.text,
+            lua_filename:lua_chunkname, lua_file:lua_str
+            lua_to_nomsu: {}, nomsu_to_lua: {}
+        }
+        metadata, lua_offset = {}, 1
+        lua_offset = 1
+        walk = (lua)->
+            if type(lua) == 'string'
+                lua_offset += #lua
+            else
+                lua_start = lua_offset
+                for b in lua.bits
+                    walk b
+                lua_stop = lua_offset
+                nomsu_src, lua_src = lua.souce, Location(lua_chunkname, lua_str, lua_start, lua_stop)
+                metadata.lua_to_nomsu[lua_src] = nomsu_src
+                metadata.nomsu_to_lua[nomsu_src] = lua_src
+        walk self
+        return lua_str, metadata
+
+class LuaValue extends Lua
+    is_statement: false
+    is_value: true
+
+    __new: (@source, ...)=>
+        @bits = {...}
+
+    as_statements: =>
+        bits = {unpack @bits}
+        bits[#bits+1] = ";"
+        return Lua(@source, bits)
+
+    parenthesize: =>
+        @prepend "("
+        @append ")"
+
+return {:Lua, :LuaValue}