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|
#..
This File contains rules for making rules and macros and some helper functions to make
that easier.
# Macros:
lua block ".."
|local function make_fn(wrap_in_block)
| return function(compiler, vars, kind)
# Do a minimal amount of pre-processing (get the aliases and the source)
| local aliases = compiler:repr(compiler:get_aliases(vars.macro_def))
| local src = compiler:repr(vars.user_macro.src)
| local user_macro = compiler:tree_to_lua(vars.user_macro)
# Then produce a block of code that creates the macro at runtime
| local lua = [[
| compiler:defmacro(%s, (function(compiler, vars, kind)
| if kind == "Expression" then
| compiler:error("Macro "..%s.." was defined to be a block, but is being used as an expression")
| end
| local user_macro = %s
| local lua = user_macro(compiler, vars)
| %s
| return lua, true
| end), %s)
| ]]
| lua = lua:format(aliases, compiler:repr(aliases), user_macro,
| wrap_in_block and [[lua = "do\\n "..lua.."\\nend"]] or "", src)
| return lua, true
| end
|end
|compiler:defmacro("macro statement %macro_def = %user_macro", make_fn(false), "see:lib/metaprogramming.nom")
|compiler:defmacro("macro block %macro_def = %user_macro", make_fn(true), "see:lib/metaprogramming.nom")
macro statement [macro %macro_def = %user_macro] =:
".."|compiler:defmacro(
| \lua expr "compiler:get_aliases(vars.macro_def)"\,
| \lua expr "compiler:tree_to_lua(vars.user_macro)"\,
| \lua expr "compiler:repr(vars.user_macro.src)"\)
macro [compiler] =: "compiler"
macro [compiler's %key] =: ".."|compiler[\%key as lua\]
macro [compiler %method %args] =:
lua block ".."
|local args = {"compiler"}
|for _,arg in ipairs(vars.args.value) do
| table.insert(args, compiler:tree_to_lua(arg))
|end
|return "compiler["..compiler:repr(compiler:tree_to_value(vars.method, vars)).."]("..table.concat(args, ", ")..")"
macro [compiler utils %method %args] =:
lua block ".."
|local args = {}
|for i,arg in ipairs(vars.args.value) do
| args[i] = compiler:tree_to_lua(arg)
|end
|return "compiler.utils["..compiler:repr(compiler:tree_to_value(vars.method, vars)).."]("..table.concat(args, ", ")..")"
# Macro that lets you make new rules
#..
This is a macro instead of a rule because it needs to pre-empt processing the list of
function calls and convert it into a list of strings (rather than call a function that
is currently in the middle of being defined). Being a macro also allows us to snatch
the source code and store that
macro statement [rule %rule_def = %body] =: ".."
|compiler:def(
| \compiler "repr" [compiler "get_aliases" [%rule_def]]\,
| \compiler "tree_to_lua" [%body]\,
| \compiler "repr" [lua expr "vars.body.src"]\)
rule [fart]=: lua block "print('poot')"
macro block [alias %aliases = %aliased] =:
lua block ".."
|local aliases = compiler:get_aliases(vars.aliases)
|aliases = compiler:repr(aliases)
|if vars.aliased.type ~= "Thunk" then
| compiler:error("Right hand side of alias % = % should be a Thunk, but got "..vars.aliased.type
| ..". Maybe you used = instead of =: by mistake?")
|end
|local aliased = next(compiler:get_aliases(vars.aliased.value))
|aliased = compiler:repr(aliased)
|local lua = ([[
|compiler:add_aliases(%s, compiler.defs[%s])
|]]):format(aliases, aliased)
|return lua
# Get the source code for a function
rule [help %rule] =:
lua block ".."
|local fn_def = compiler:get_fn_def(vars.rule)
|if not fn_def then
| compiler:writeln("Rule not found: "..compiler:repr(vars.rule))
|else
| compiler:writeln("rule "..compiler:repr(compiler.utils.keys(fn_def.aliases))
| .." ="..(fn_def.src or ":\\n <unknown source code>"))
|end
# Macro helper functions
rule [%tree as value] =:
lua expr "compiler:tree_to_value(vars.tree, vars)"
rule [%tree as lua] =:
lua expr "compiler:tree_to_lua(vars.tree)"
rule [test, foobar] =: lua expr "print('yup')"
# Compiler tools
rule [eval %code, run %code] =: compiler "run" [%code]
rule [source code from tree %tree] =:
lua block ".."
|local _,_,leading_space = vars.tree.src:find("\\n(%s*)%S")
|if leading_space then
| local chunk1, chunk2 = vars.tree.src:match(":%s*([^\\n]*)(\\n.*)")
| chunk2 = chunk2:gsub("\\n"..leading_space, "\\n")
| return chunk1..chunk2.."\\n"
|else
| return vars.tree.src:match(":%s*(%S.*)").."\\n"
|end
macro [source code %body] =:
compiler "repr" [compiler "call" ["source code from tree %", %body]]
macro [parse tree %code] =:
compiler "repr" [compiler "stringify_tree" [lua expr "vars.code.value"]]
|
