The Pico Printer

{ print(Exp):
 { indent: 0;
 
 print_expression(Exp):
 void;
 print_list (Lst, Ini, Sep, Trm):
 { display(Ini);
 if(size(Lst)> 0,
 { print(Lst[1]);
 for(k: 2, k:= k+1, not(k> size(Lst)),
 { display(Sep); 
 print_expression(Lst[k]) }) },
 void);
 display(Trm) };
 print_number (Exp):
 { val: Exp[NBR_VAL_idx];
 display(val) };
 print_fraction (Exp):
 { val: Exp[FRC_VAL_idx];
 display(val) };
 print_text (Exp):
 { val: Exp[TXT_VAL_idx];
 display(val) };
 print_table (Exp):
 { tab: Exp[TAB_TAB_idx];
 print_list(tab, '[', ',', ']') };
 print_function (Exp):
 { nam: Exp[FUN_NAM_idx];
 display('') };
 print_native (Exp):
 { nam: Exp[NAT_Nam_idx];
 display('') };
 print_void (Exp):
 display('');
 
 print_variable (Exp): 
 { nam: Exp[VAR_NAM_idx];
 display(nam) };
 
 print_application (Exp): 
 { nam: Exp[APL_NAM_idx];
 arg: Exp[APL_ARG_idx];
 display(nam);
 if(arg[TAG_idx] = TAB_tag,
 { tab: arg[TAB_TAB_idx];
 print_list(tab, '(', ',', ')') },
 { display('@');
 print_expression(arg) })};
 
 print_tabulation (Exp): 
 { nam: Exp[TBL_NAM_idx];
 idx: Exp[TBL_IDX_idx];
 display(nam, '[');
 print_expression(idx);
 display(']') };
 
 print_definition (Exp): 
 { inv: Exp[DEF_INV_idx];
 exp: Exp[DEF_EXP_idx];
 print_expression(inv);
 display(': ');
 print_expression(exp) };
 
 print_assignment (Exp): 
 { inv: Exp[SET_INV_idx];
 exp: Exp[SET_EXP_idx];
 print_expression(inv);
 display(':= ');
 print_expression(exp) };
 
 print_dictionary (Exp): 
 display('');
 
 exp_case : case(NBR_tag => print_number,
 FRC_tag => print_fraction,
 TXT_tag => print_text,
 TAB_tag => print_table,
 FUN_tag => print_function,
 NAT_tag => print_native,
 VAR_tag => print_variable,
 APL_tag => print_application,
 TBL_tag => print_tabulation,
 DEF_tag => print_definition,
 SET_tag => print_assignment,
 DCT_tag => print_dictionary,
 VOI_tag => print_void);
 
 print_expression (Exp):=
 { cas: exp_case(Exp[TAG_idx]);
 cas(Exp) };
 
 print (Exp):=
 { indent:= 0;
 print_expression(Exp) };
 
 print(Exp) };
 display('printer installed', eoln)}

This page was made (with lots of hard work!) by Wolfgang De Meuter