diff options
Diffstat (limited to 'examples/decaf_parser.py')
| -rw-r--r-- | examples/decaf_parser.py | 266 |
1 files changed, 176 insertions, 90 deletions
diff --git a/examples/decaf_parser.py b/examples/decaf_parser.py index e6b1abb..be3a1e9 100644 --- a/examples/decaf_parser.py +++ b/examples/decaf_parser.py @@ -12,46 +12,75 @@ """ Program ::= Decl+ Decl ::= VariableDecl | FunctionDecl | ClassDecl | InterfaceDecl - VariableDecl ::= Variable ; - Variable ::= Type ident - Type ::= int | double | bool | string | ident | Type [] - FunctionDecl ::= Type ident ( Formals ) StmtBlock | void ident ( Formals ) StmtBlock - Formals ::= Variable+, | e - ClassDecl ::= class ident <extends ident> <implements ident + ,> { Field* } - Field ::= VariableDecl | FunctionDecl - InterfaceDecl ::= interface ident { Prototype* } - Prototype ::= Type ident ( Formals ) ; | void ident ( Formals ) ; - StmtBlock ::= { VariableDecl* Stmt* } - Stmt ::= <Expr> ; | IfStmt | WhileStmt | ForStmt | BreakStmt | ReturnStmt | PrintStmt | StmtBlock - IfStmt ::= if ( Expr ) Stmt <else Stmt> - WhileStmt ::= while ( Expr ) Stmt - ForStmt ::= for ( <Expr> ; Expr ; <Expr> ) Stmt - ReturnStmt ::= return <Expr> ; - BreakStmt ::= break ; - PrintStmt ::= Print ( Expr+, ) ; + VariableDecl ::= Variable ; + Variable ::= Type ident + Type ::= int | double | bool | string | ident | Type [] + FunctionDecl ::= Type ident ( Formals ) StmtBlock | void ident ( Formals ) StmtBlock + Formals ::= Variable+, | e + ClassDecl ::= class ident <extends ident> <implements ident + ,> { Field* } + Field ::= VariableDecl | FunctionDecl + InterfaceDecl ::= interface ident { Prototype* } + Prototype ::= Type ident ( Formals ) ; | void ident ( Formals ) ; + StmtBlock ::= { VariableDecl* Stmt* } + Stmt ::= <Expr> ; | IfStmt | WhileStmt | ForStmt | BreakStmt | ReturnStmt | PrintStmt | StmtBlock + IfStmt ::= if ( Expr ) Stmt <else Stmt> + WhileStmt ::= while ( Expr ) Stmt + ForStmt ::= for ( <Expr> ; Expr ; <Expr> ) Stmt + ReturnStmt ::= return <Expr> ; + BreakStmt ::= break ; + PrintStmt ::= Print ( Expr+, ) ; Expr ::= LValue = Expr | Constant | LValue | this | Call - | ( Expr ) - | Expr + Expr | Expr - Expr | Expr * Expr | Expr / Expr | Expr % Expr | - Expr - | Expr < Expr | Expr <= Expr | Expr > Expr | Expr >= Expr | Expr == Expr | Expr != Expr - | Expr && Expr | Expr || Expr | ! Expr - | ReadInteger ( ) | ReadLine ( ) | new ident | NewArray ( Expr , Typev) - LValue ::= ident | Expr . ident | Expr [ Expr ] - Call ::= ident ( Actuals ) | Expr . ident ( Actuals ) - Actuals ::= Expr+, | e + | ( Expr ) + | Expr + Expr | Expr - Expr | Expr * Expr | Expr / Expr | Expr % Expr | - Expr + | Expr < Expr | Expr <= Expr | Expr > Expr | Expr >= Expr | Expr == Expr | Expr != Expr + | Expr && Expr | Expr || Expr | ! Expr + | ReadInteger ( ) | ReadLine ( ) | new ident | NewArray ( Expr , Typev) + LValue ::= ident | Expr . ident | Expr [ Expr ] + Call ::= ident ( Actuals ) | Expr . ident ( Actuals ) + Actuals ::= Expr+, | e Constant ::= intConstant | doubleConstant | boolConstant | stringConstant | null """ import pyparsing as pp from pyparsing import pyparsing_common as ppc + pp.ParserElement.enablePackrat() # keywords -keywords = (VOID, INT, DOUBLE, BOOL, STRING, CLASS, INTERFACE, NULL, THIS, EXTENDS, IMPLEMENTS, FOR, WHILE, - IF, ELSE, RETURN, BREAK, NEW, NEWARRAY, PRINT, READINTEGER, READLINE, TRUE, FALSE) = map(pp.Keyword, - """void int double bool string class interface null this extends implements or while - if else return break new NewArray Print ReadInteger ReadLine true false""".split()) +keywords = ( + VOID, + INT, + DOUBLE, + BOOL, + STRING, + CLASS, + INTERFACE, + NULL, + THIS, + EXTENDS, + IMPLEMENTS, + FOR, + WHILE, + IF, + ELSE, + RETURN, + BREAK, + NEW, + NEWARRAY, + PRINT, + READINTEGER, + READLINE, + TRUE, + FALSE, +) = map( + pp.Keyword, + """void int double bool string class interface null this extends implements or while + if else return break new NewArray Print ReadInteger ReadLine true false""".split(), +) keywords = pp.MatchFirst(list(keywords)) -LPAR, RPAR, LBRACE, RBRACE, LBRACK, RBRACK, DOT, EQ, COMMA, SEMI = map(pp.Suppress, "(){}[].=,;") +LPAR, RPAR, LBRACE, RBRACE, LBRACK, RBRACK, DOT, EQ, COMMA, SEMI = map( + pp.Suppress, "(){}[].=,;" +) hexConstant = pp.Regex(r"0[xX][0-9a-fA-F]+").addParseAction(lambda t: int(t[0][2:], 16)) intConstant = hexConstant | ppc.integer doubleConstant = ppc.real @@ -59,7 +88,7 @@ boolConstant = TRUE | FALSE stringConstant = pp.dblQuotedString null = NULL constant = doubleConstant | boolConstant | intConstant | stringConstant | null -ident = ~keywords + pp.Word(pp.alphas, pp.alphanums+'_') +ident = ~keywords + pp.Word(pp.alphas, pp.alphanums + "_") type_ = pp.Group((INT | DOUBLE | BOOL | STRING | ident) + pp.ZeroOrMore("[]")) variable = type_ + ident @@ -68,86 +97,142 @@ variable_decl = variable + SEMI expr = pp.Forward() expr_parens = pp.Group(LPAR + expr + RPAR) actuals = pp.Optional(pp.delimitedList(expr)) -call = pp.Group(ident("call_ident") + LPAR + actuals("call_args") + RPAR - | (expr_parens + pp.ZeroOrMore(DOT + ident))("call_ident_expr") + LPAR + actuals("call_args") + RPAR) -lvalue = ((ident | expr_parens) - + pp.ZeroOrMore(DOT + (ident | expr_parens)) - + pp.ZeroOrMore(LBRACK + expr + RBRACK)) +call = pp.Group( + ident("call_ident") + LPAR + actuals("call_args") + RPAR + | (expr_parens + pp.ZeroOrMore(DOT + ident))("call_ident_expr") + + LPAR + + actuals("call_args") + + RPAR +) +lvalue = ( + (ident | expr_parens) + + pp.ZeroOrMore(DOT + (ident | expr_parens)) + + pp.ZeroOrMore(LBRACK + expr + RBRACK) +) assignment = pp.Group(lvalue("lhs") + EQ + expr("rhs")) read_integer = pp.Group(READINTEGER + LPAR + RPAR) read_line = pp.Group(READLINE + LPAR + RPAR) new_statement = pp.Group(NEW + ident) new_array = pp.Group(NEWARRAY + LPAR + expr + COMMA + type_ + RPAR) rvalue = constant | call | read_integer | read_line | new_statement | new_array | ident -arith_expr = pp.infixNotation(rvalue, +arith_expr = pp.infixNotation( + rvalue, [ - ('-', 1, pp.opAssoc.RIGHT,), - (pp.oneOf("* / %"), 2, pp.opAssoc.LEFT,), - (pp.oneOf("+ -"), 2, pp.opAssoc.LEFT,), - ]) -comparison_expr = pp.infixNotation(arith_expr, + ("-", 1, pp.opAssoc.RIGHT,), + (pp.oneOf("* / %"), 2, pp.opAssoc.LEFT,), + (pp.oneOf("+ -"), 2, pp.opAssoc.LEFT,), + ], +) +comparison_expr = pp.infixNotation( + arith_expr, [ - ('!', 1, pp.opAssoc.RIGHT,), - (pp.oneOf("< > <= >="), 2, pp.opAssoc.LEFT,), - (pp.oneOf("== !="), 2, pp.opAssoc.LEFT,), - (pp.oneOf("&&"), 2, pp.opAssoc.LEFT,), - (pp.oneOf("||"), 2, pp.opAssoc.LEFT,), - ]) -expr <<= (assignment - | call - | THIS - | comparison_expr - | arith_expr - | lvalue - | constant - | read_integer - | read_line - | new_statement - | new_array - ) + ("!", 1, pp.opAssoc.RIGHT,), + (pp.oneOf("< > <= >="), 2, pp.opAssoc.LEFT,), + (pp.oneOf("== !="), 2, pp.opAssoc.LEFT,), + (pp.oneOf("&&"), 2, pp.opAssoc.LEFT,), + (pp.oneOf("||"), 2, pp.opAssoc.LEFT,), + ], +) +expr <<= ( + assignment + | call + | THIS + | comparison_expr + | arith_expr + | lvalue + | constant + | read_integer + | read_line + | new_statement + | new_array +) stmt = pp.Forward() -print_stmt = pp.Group(PRINT("statement") + LPAR + pp.Group(pp.Optional(pp.delimitedList(expr)))("args") + RPAR + SEMI) +print_stmt = pp.Group( + PRINT("statement") + + LPAR + + pp.Group(pp.Optional(pp.delimitedList(expr)))("args") + + RPAR + + SEMI +) break_stmt = pp.Group(BREAK("statement") + SEMI) return_stmt = pp.Group(RETURN("statement") + expr + SEMI) -for_stmt = pp.Group(FOR("statement") + LPAR + pp.Optional(expr) + SEMI + expr + SEMI + pp.Optional(expr) + RPAR + stmt) +for_stmt = pp.Group( + FOR("statement") + + LPAR + + pp.Optional(expr) + + SEMI + + expr + + SEMI + + pp.Optional(expr) + + RPAR + + stmt +) while_stmt = pp.Group(WHILE("statement") + LPAR + expr + RPAR + stmt) -if_stmt = pp.Group(IF("statement") - + LPAR + pp.Group(expr)("condition") + RPAR - + pp.Group(stmt)("then_statement") - + pp.Group(pp.Optional(ELSE + stmt))("else_statement")) -stmt_block = pp.Group(LBRACE + pp.ZeroOrMore(variable_decl) + pp.ZeroOrMore(stmt) + RBRACE) -stmt <<= (if_stmt - | while_stmt - | for_stmt - | break_stmt - | return_stmt - | print_stmt - | stmt_block - | pp.Group(expr + SEMI) - ) +if_stmt = pp.Group( + IF("statement") + + LPAR + + pp.Group(expr)("condition") + + RPAR + + pp.Group(stmt)("then_statement") + + pp.Group(pp.Optional(ELSE + stmt))("else_statement") +) +stmt_block = pp.Group( + LBRACE + pp.ZeroOrMore(variable_decl) + pp.ZeroOrMore(stmt) + RBRACE +) +stmt <<= ( + if_stmt + | while_stmt + | for_stmt + | break_stmt + | return_stmt + | print_stmt + | stmt_block + | pp.Group(expr + SEMI) +) formals = pp.Optional(pp.delimitedList(variable)) -prototype = pp.Group((type_ | VOID)("return_type") - + ident("function_name") - + LPAR + formals("args") + RPAR + SEMI)("prototype") -function_decl = pp.Group((type_ | VOID)("return_type") + ident("function_name") - + LPAR + formals("args") + RPAR - + stmt_block("body"))("function_decl") +prototype = pp.Group( + (type_ | VOID)("return_type") + + ident("function_name") + + LPAR + + formals("args") + + RPAR + + SEMI +)("prototype") +function_decl = pp.Group( + (type_ | VOID)("return_type") + + ident("function_name") + + LPAR + + formals("args") + + RPAR + + stmt_block("body") +)("function_decl") -interface_decl = pp.Group(INTERFACE + ident("interface_name") - + LBRACE + pp.ZeroOrMore(prototype)("prototypes") + RBRACE)("interface") +interface_decl = pp.Group( + INTERFACE + + ident("interface_name") + + LBRACE + + pp.ZeroOrMore(prototype)("prototypes") + + RBRACE +)("interface") field = variable_decl | function_decl -class_decl = pp.Group(CLASS + ident("class_name") - + pp.Optional(EXTENDS + ident)("extends") - + pp.Optional(IMPLEMENTS + pp.delimitedList(ident))("implements") - + LBRACE + pp.ZeroOrMore(field)("fields") + RBRACE)("class_decl") +class_decl = pp.Group( + CLASS + + ident("class_name") + + pp.Optional(EXTENDS + ident)("extends") + + pp.Optional(IMPLEMENTS + pp.delimitedList(ident))("implements") + + LBRACE + + pp.ZeroOrMore(field)("fields") + + RBRACE +)("class_decl") decl = variable_decl | function_decl | class_decl | interface_decl | prototype program = pp.OneOrMore(pp.Group(decl)) decaf_parser = program -stmt.runTests("""\ +stmt.runTests( + """\ sin(30); a = 1; b = 1 + 1; @@ -158,7 +243,8 @@ stmt.runTests("""\ a[100] = b; a[0][0] = 2; a = 0x1234; -""") +""" +) test_program = """ void getenv(string var); |