Bruce Hill
7d2b7199d8
literal") shorthand, deprecating Lua value, and more use of Lua "..." with text interpolations.
106 lines
3.6 KiB
Plaintext
106 lines
3.6 KiB
Plaintext
#!/usr/bin/env nomsu -V4.8.10
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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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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(barf %msg) compiles to "error(\(=lua "\%msg and \(%msg as lua expr) or 'nil'"), 0);"
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(compile error at %tree %msg) compiles to "\
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..nomsu:compile_error(\(%tree as lua expr), \(%msg as lua expr))"
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(compile error at %tree %msg hint %hint) compiles to "\
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..nomsu:compile_error(\(%tree as lua expr), \(%msg as lua expr), \(%hint as lua expr))"
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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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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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(assume %a == %b) compiles to:
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lua> "\
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..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"
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..), 0)
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end
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end"
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(assume %condition or barf %message) compiles to "\
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..if not \(%condition as lua expr) then
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error(\(%message as lua expr), 0)
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end"
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test:
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try (barf) and if it succeeds: barf "try failed."
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%worked = (no)
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try (barf) and if it barfs: %worked = (yes)
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assume %worked or barf "try/catch failed"
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%x = 1
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try:
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%x = 2
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do (barf) then always: %x = 3
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..and if it barfs: do nothing
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assume (%x == 3) or barf "do/then always failed"
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# Try/except
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[..]
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try %action and if it succeeds %success or if it barfs %msg %fallback
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try %action and if it barfs %msg %fallback or if it succeeds %success
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..all compile to "\
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..do
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local fell_through = false
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local err, erred = nil, false
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local ok, ret = xpcall(function()
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\(%action as lua statements)
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fell_through = true
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end, function(\(=lua "\%fallback and \(%msg as lua expr) or ''"))
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local ok, ret = pcall(function()
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\((=lua "\%fallback or \%msg") as lua statements)
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end)
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if not ok then err, erred = ret, true end
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end)
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if ok then
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\(%success as lua statements)
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if not fell_through then
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return ret
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end
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elseif erred then
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error(err, 0)
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end
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end"
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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#
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[..]
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try %action and if it succeeds %success or if it barfs %fallback
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try %action and if it barfs %fallback or if it succeeds %success
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..all parse as (..)
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try %action and if it succeeds %success or if it barfs (=lua "") %fallback
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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(try %action) parses as (..)
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try %action and if it succeeds (do nothing) or if it barfs (do nothing)
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#(try %action and if it barfs %fallback) parses as (..)
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try %action and if it succeeds (do nothing) or if it barfs %fallback
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(try %action and if it barfs %msg %fallback) parses as (..)
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try %action and if it succeeds (do nothing) or if it barfs %msg %fallback
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(try %action and if it succeeds %success) parses as (..)
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try %action and if it succeeds %success or if it barfs (do nothing)
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