Support "a bit more concatenative" syntax.
Chris Pressey
1 year, 10 months ago
| 313 | 313 |
fac1 =& dup int[0] gt!;
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fac2 =| fac3 fac4;
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fac3 =& dup int[1] eq!;
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fac4 =& dup int[1] sub fact mul;
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There! Are you happy now?
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fac4 =& pop dup int[1] sub fact mul;
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main =& int[5] fact;
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==> OK([120])
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There! <s>Are you happy now?</s> Don't that just beat all?
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In light of this stellar feature it is expected that serious
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programmers would treat the plain `=` form of definition as
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a sort of "wimpmode" and shun it.
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fact =& fac1 fac2;
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fac1 =& dup int[0] gt!;
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fac2 =| fac3 fac4;
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fac3 =& dup int[1] eq!;
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fac4 =& pop dup int[1] sub fact mul;
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main =& int[5] fact;
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#
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# Program ::= {Definition}.
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# Definition ::= name<def> "=" Expression ";".
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# Definition ::= name<def> ("=" Expression | "=&" Term | "=|" Term) ";".
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# Expression ::= Term {"|" Term}.
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# Term ::= Atom {Atom}.
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# Atom ::= "(" Expression ")" | name<use> [bracketedtext].
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def definition(self):
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name = self.scanner.token
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self.scanner.scan()
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self.scanner.expect('=')
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expr = self.expression()
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if self.scanner.consume('='):
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expr = self.expression()
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elif self.scanner.consume('=&'):
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expr = self.term()
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elif self.scanner.consume('=|'):
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expr = self.term(constructor=Else)
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else:
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raise ParseError('Expected `=`, `=&`, or `=|`')
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self.scanner.expect(';')
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self.definitions[name] = expr
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t1 = Else(t1, t2)
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return t1
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| 39 | 45 |
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def term(self):
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def term(self, constructor=Then):
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a1 = self.atom()
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while self.scanner.on_type('word') or self.scanner.token == '(':
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a2 = self.atom()
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a1 = Then(a1, a2)
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a1 = constructor(a1, a2)
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return a1
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def atom(self):
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| 34 | 34 |
self.token = None
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self.type = 'EOF'
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return
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if self.scan_pattern(u'\\|', 'operator'):
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if self.scan_pattern(r'\||\=\&|\=\||\=', 'operator'):
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return
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| 39 | 39 |
if self.scan_pattern(r'\;', 'punct'):
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return
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