Bruce Hill
b6d3cbd61c
relative to the text, not the opening '("', code objects can now remove
all free vars, the REPL uses global vars. Error API is changing a bit.
124 lines
3.6 KiB
Plaintext
124 lines
3.6 KiB
Plaintext
#!/usr/bin/env nomsu -V6.13.12.8
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#
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This file contains basic error reporting code
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use "core/metaprogramming.nom"
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use "core/operators.nom"
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(fail $msg) compiles to
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"error(\(($msg as lua expr) if $msg else "nil"), 0);"
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(assume $condition) compiles to:
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lua> ("
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local \$assumption = 'Assumption failed: '..tostring((\$condition):get_source_code())
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")
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return
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Lua ("
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if not \($condition as lua expr) then
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error(\(quote "\$assumption"), 0)
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end
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")
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(assume $a == $b) compiles to:
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lua> "local \$assumption = 'Assumption failed: '..tostring(\(\($a == $b) as nomsu))"
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define mangler
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return
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Lua ("
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do
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local \(mangle "a"), \(mangle "b") = \($a as lua expr), \($b as lua expr)
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if \(mangle "a") ~= \(mangle "b") then
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error(\(quote "\$assumption").."\\n"..tostring(\(mangle "a")).." != "..tostring(\
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..\(mangle "b")), 0)
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end
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end
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")
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test:
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try: fail
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$worked = (no)
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try: fail
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..if it fails:
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$worked = (yes)
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..if it succeeds:
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fail "'try' incorrectly ran success case."
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unless $worked:
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fail "'try' failed to recover from failure"
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# Try/except
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[
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try $action if it succeeds $success if it fails $fallback
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try $action if it fails $fallback if it succeeds $success
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] all compile to:
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$success_lua = ($success as lua)
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if ((#"\$success_lua") > 0): $success_lua, add "\n"
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$success_lua, prepend "-- Success:\n"
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$success_lua, add "if not _fell_through then return table.unpack(_result, 2) end"
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$fallback_lua = ($fallback as lua)
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if ((#"\$fallback_lua") > 0):
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$fallback_lua, prepend "\nlocal function failure() return _result[2] end\n"
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$fallback_lua, prepend "-- Failure:"
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return
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Lua ("
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do
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local _fell_through = false
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local _result = {pcall(function()
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\($action as lua)
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_fell_through = true
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end)}
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if _result[1] then
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\$success_lua
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else
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\$fallback_lua
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end
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end
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")
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(try $action) parses as
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try $action if it succeeds (do nothing) if it fails (do nothing)
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(try $action if it fails $msg $fallback) parses as
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try $action if it succeeds (do nothing) if it fails $msg $fallback
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(try $action if it succeeds $success) parses as
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try $action if it succeeds $success if it fails (do nothing)
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(try $action if it fails $fallback if it succeeds $success) parses as
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try $action if it succeeds $success if it fails $fallback
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test:
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$success = (no)
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try:
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do: fail
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..then always:
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$success = (yes)
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..if it succeeds:
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fail "'try ... then always ...' didn't propagate failure"
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unless $success:
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fail "'try ... then always ...' didn't execute the 'always' code"
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(do $action then always $final_action) compiles to ("
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do -- do/then always
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local _fell_through = false
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local _results = {pcall(function()
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\($action as lua)
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_fell_through = true
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end)}
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\($final_action as lua)
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if not _results[1] then error(_results[2], 0) end
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if not _fell_through then return table.unpack(_results, 2) end
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end
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")
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~~~
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(barf $) parses as (fail $)
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(assume $1 or barf $2) parses as (unless $1: fail $2)
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