Sha256: f31609ef159eb1cca3d5267a71edb039e4faccf7feef9c8b72a40a5801cf3ed7
Contents?: true
Size: 824 Bytes
Versions: 10
Compression:
Stored size: 824 Bytes
Contents
#
# A simple calculator, version 3.
#
class Calculator3
prechigh
nonassoc UMINUS
left '*' '/'
left '+' '-'
preclow
options no_result_var
rule
target : exp
| /* none */ { 0 }
exp : exp '+' exp { val[0] + val[2] }
| exp '-' exp { val[0] - val[2] }
| exp '*' exp { val[0] * val[2] }
| exp '/' exp { val[0] / val[2] }
| '(' exp ')' { val[1] }
| '-' NUMBER =UMINUS { -(val[1]) }
| NUMBER
end
---- header ----
#
# generated by racc
#
require 'calc3.rex'
---- inner ----
---- footer ----
puts 'sample calc'
puts '"q" to quit.'
calc = Calculator3.new
while true
print '>>> '; $stdout.flush
str = $stdin.gets.strip
break if /q/i === str
begin
p calc.scan_str(str)
rescue ParseError
puts 'parse error'
end
end
Version data entries
10 entries across 10 versions & 4 rubygems