nomsu/pretty_errors.moon
Bruce Hill bc41cc3a24 Switched to have colors/utf8 be optional, fixed an issue with currently
running files leaking when errors occurred (causing spurious circular
import errors), and improved tutorial.
2019-01-29 16:17:33 -08:00

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-- This file has code for converting errors to user-friendly format, with colors,
-- line numbers, code excerpts, and so on.
require "containers"
Text = require 'text'
C = require 'colors'
box = (text)->
max_line = 0
for line in text\gmatch("[^\n]+")
max_line = math.max(max_line, #(line\gsub("\027%[[0-9;]*m","")))
ret = ("\n"..text)\gsub "\n([^\n]*)", (line)->
line_len = #(line\gsub("\027%[[0-9;]*m",""))
return "\n#{line}#{(" ")\rep(max_line-line_len)} "..C('reset')
return ret\sub(2,-1), max_line
format_error = (err)->
context = err.context or 2
err_line, err_linenum, err_linepos = err.source\line_info_at(err.start)
-- TODO: better handle multi-line errors
err_size = math.min((err.stop - err.start), (#err_line-err_linepos) + 1)
nl_indicator = (err_linepos > #err_line) and " " or ""
fmt_str = " %#{#tostring(err_linenum+context)}d|"
pointer = (" ")\rep(err_linepos+#fmt_str\format(0)-1)..("^")\rep(err_size)
--pointer = if err_size >= 2
-- (" ")\rep(err_linepos+#fmt_str\format(0)-1).."╚#{("═")\rep(err_size-2)}╝"
--else
-- (" ")\rep(err_linepos+#fmt_str\format(0)-1).."⬆"
err_msg = C('bold red', err.title or "Error")..C('red', " at #{err.filename or '???'}:#{err_linenum},#{err_linepos}")
err_msg ..= "\n" unless COLOR_ENABLED
lines = err.source\lines!
for i=err_linenum-context,err_linenum-1
if line = lines[i]
err_msg ..= "\n"..C('dim', fmt_str\format(i))..line
if err_line
before = err_line\sub(1, err_linepos-1)
during = err_line\sub(err_linepos,err_linepos+err_size-1)
after = err_line\sub(err_linepos+err_size, -1)
err_line = before..C('black on red', during..nl_indicator)..after
err_msg ..= "\n"..C('dim', fmt_str\format(err_linenum))..err_line
_, err_linenum_end, err_linepos_end = err.source\line_info_at(err.stop)
err_linenum_end or= err_linenum
if err_linenum_end == err_linenum
err_msg ..= "\n#{pointer}"
else
for i=err_linenum+1,err_linenum_end
if line = lines[i]
if i == err_linenum_end
during, after = line\sub(1,err_linepos_end-1), line\sub(err_linepos_end,-1)
err_msg ..= "\n"..C('dim', fmt_str\format(i))..C('black on red', during)..after
else
err_msg ..= "\n"..C('dim', fmt_str\format(i))..C('black on red', line)
if i > err_linenum+1 + 5
err_msg ..= "\n ...\n"
break
box_width = 70
err_text = C('black on white', " "..err.error\wrapped_to(box_width, 16)\gsub("\n", "\n"..C('black on white').." "))
if err.hint
err_text ..= "\n"..C('italic black on white', (" Suggestion: #{err.hint}")\wrapped_to(box_width, 16)\gsub("\n", "\n"..C('italic black on white').." "))
err_msg ..= "\n "..box(err_text)\gsub("\n", "\n ")
err_msg ..= "\n" unless COLOR_ENABLED
for i=err_linenum_end+1,err_linenum_end+context
if line = lines[i]
err_msg ..= "\n"..C('dim', fmt_str\format(i))..line
err_msg ..= "\n" unless COLOR_ENABLED
return err_msg
return format_error