For 2, Prolog - rextester

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objeto :- write('{'),aux1, write('}').
aux1 :- read(X),(X='atributo'->atributo;
                 X='fin'->write('')).
atributo :-read(X),write('"'),write(X),write('"'), write(':'),valorobjeto(X),aux2.
valorobjeto(M):-read(Y),(Y='cadena'->cadena;
                 Y='numero'->numero;
                 Y='objeto'->objeto;
                 Y='arreglo'->arreglo;
                 Y='metodo'->metodo(M);
                 Y='true'->verdadero;
                 Y='false'->falso).
aux2 :- read(X),(X='atributo'->write(','),atributo;
                 X='fin'->write('')). 
cadena :- read(X),write('"'),write(X),write('"').
numero :- read(N),write(N).
arreglo :- write('['),aux3,write(']').
aux3 :- read(X),(X='valor'->valorarreglo,aux4;
                 X='fin'->write('')).
aux4 :- read(X),(X='valor'->write(','),valorarreglo,aux4;
                 X='fin'->write('')). 
valorarreglo :-read(Y),(Y='cadena'->cadena;
                 Y='numero'->numero;
                 Y='objeto'->objeto;
                 Y='arreglo'->arreglo;
                 Y='true'->verdadero;
                 Y='false'->falso).
verdadero :- write('true').
falso :- write('false').
metodo(M) :- write('"function() {'),instruccion, write('return '),write(M),write('}"').
instruccion :- read(I),(I='asignacion'->asignacion,instruccion;
                 I='decision' ->decision,instruccion;
                 I='ciclo' ->ciclo,instruccion;
                 I='fin'->write('')).
ciclo :- write('for(i in '),read(X),write(X),propiedad,write('){'),instruccion.
propiedad :- write('.'),read(X),write(X),array.
array :- read(X), (X = 'si' ->write('['),numero,write(']'),aux6;
                   X = 'no' ->write(''),aux6).
aux6 :- read(X),(X = 'propiedad' -> propiedad;
                 X = 'fin' -> write('')).
asignacion :- read(X),write(X),write('='),read(Y),write(Y),write(';').
decision :- write('if ('),read(C),write(C),write(') {'),instruccion,write('}'),aux5.
aux5 :- read(X),(X='sino'->write('else {'),instruccion,write('}');
                 X='fin'->write('')).
:- objeto.

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