%{
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/* compile: leg -o calc.c calc.leg
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* cc -o calc calc.c
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*
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* run: ( echo a=2*3; echo b=3+4; echo c=a*b ) | ./calc
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*/
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#define SYMBOL_PAYLOAD \
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oop value; \
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int defined
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#define SYMBOL_INITIALISE(S) \
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S.value = null; \
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S.defined = false
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#include "object.c"
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// this should stay out of object.c because it manipulates Symbol members defined in this file
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oop update_symbol_value(oop symbol, oop integer)
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{
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//_checkType(symbol, Symbol);
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// For now it will fail with assigning to null
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// because for now we can write "a=2 b=a" because everything is passed by value
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//_checkType(integer, Integer);
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set(symbol, Symbol, value, integer); // checktyype is implicit, and it's ok for symbols to store any object value?
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return symbol;
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}
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#define YYSTYPE oop
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YYSTYPE yylval;
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%}
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start = e:exp { yylval = e }
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exp = - (a:assign { $$ = a }
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| d:delete { $$ = d }
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| p:prim { $$ = p }
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)
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assign = l:IDENT EQUAL p:prim { $$ = update_symbol_value(l, p) }
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# it is really unhappy that I have to repeate the code in value because
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# I need both information: map identifier and the key
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delete = DEL
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( i:IDENT DOT p:STRING
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| i:IDENT LBRAC p:prim RBRAC
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) { $$ = map_del(get(i, Symbol, value), p) }
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prim = ( s:sum { $$ = s }
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| s:string { $$ = s }
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| m:map { $$ = m }
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)
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# Map
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map = LCB RCB { $$ = makeMap() }
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| LCB p:prop RCB { $$ = p; }
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prop = k:STRING COLON v:prim COMMA p:prop { $$ = map_set(p, k, v) }
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| k:STRING COLON v:prim { $$ = map_set(makeMap(), k, v) }
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# String
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string = (SQUOTE | DQUOTE) s:STRING (SQUOTE | DQUOTE) { $$ = s }
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# Number
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sum = l:prod
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( PLUS+ r:prod { get(l, Integer, value) += get(r, Integer, value) }
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| MINUS r:prod { get(l, Integer, value) -= get(r, Integer, value) }
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)* { $$ = l }
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prod = l:sign
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( MULTI r:sign { get(l, Integer, value) *= get(r, Integer, value) }
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| DIVIDE r:sign { get(l, Integer, value) /= get(r, Integer, value) }
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| MODULO r:sign { get(l, Integer, value) %= get(r, Integer, value) }
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)* { $$ = l }
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sign = MINUS n:sign { set(n, Integer, value, -get(n, Integer, value)); $$ = n }
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| PLUS n:sign { $$ = n }
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| n:value { $$ = n }
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value = n:NUMBER { $$ = n }
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| NULL { $$ = null }
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| i:IDENT DOT s:STRING { $$ = map_get(get(i, Symbol, value), s) }
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# Here between the [ ] I put an exp but the only possible type is String so it is pretty limited
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# And I might directly write "prim"?
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| i:IDENT LBRAC p:exp RBRAC { $$ = map_get(get(i, Symbol, value), p) }
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| i:IDENT { $$ = get(i, Symbol, value) }
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- = [ \t\n\r]*
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IDENT = < [a-zA-Z][a-zA-Z0-9_]* > - { $$ = intern(yytext) }
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STRING = < [a-zA-Z][a-zA-Z0-9_]* > - { $$ = makeString(yytext) }
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NUMBER = < [0-9]+ > - { $$ = makeInteger(atoi(yytext)) }
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PLUS = '+' -
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MINUS = '-' -
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MULTI = '*' -
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DIVIDE = '/' -
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MODULO = '%' -
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EQUAL = '=' -
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NULL = 'null' -
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DEL = 'del' -
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COLON = ':' -
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COMMA = ',' -
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DOT = '.' -
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LCB = '{' -
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RCB = '}' -
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LBRAC = '[' -
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RBRAC = ']' -
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DQUOTE = '"' -
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SQUOTE = "'" -
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%%
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int main(int argc, char **argv)
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{
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while (yyparse()) {
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println(yylval);
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}
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return 0;
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}
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