| (* Copyright (C) 2015 Free Software Foundation, Inc. *) | |
| (* This file is part of GNU Modula-2. | |
| GNU Modula-2 is free software; you can redistribute it and/or modify it under | |
| the terms of the GNU General Public License as published by the Free | |
| Software Foundation; either version 3, or (at your option) any later | |
| version. | |
| GNU Modula-2 is distributed in the hope that it will be useful, but WITHOUT ANY | |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| for more details. | |
| You should have received a copy of the GNU General Public License along | |
| with gm2; see the file COPYING. If not, write to the Free Software | |
| Foundation, 51 Franklin Street, Fifth Floor, | |
| Boston, MA 02110-1301, USA. *) | |
| MODULE tinyvarient6 ; (*!m2pim*) | |
| CONST | |
| MaxCodeHunkLength = 4 ; | |
| TYPE | |
| Name = CARDINAL ; | |
| ElementType = (idel, tokel, litel) ; | |
| m2condition = (m2none, m2if, m2elsif, m2while) ; | |
| TraverseResult = (unknown, true, false) ; | |
| ProductionDesc = POINTER TO productiondesc ; | |
| IdentDesc = POINTER TO identdesc ; (* forward fodder for p2c *) | |
| identdesc = RECORD | |
| definition: ProductionDesc ; (* where this idents production is defined *) | |
| name : Name ; | |
| line : CARDINAL ; | |
| END ; | |
| SetDesc = POINTER TO setdesc ; | |
| setdesc = RECORD | |
| next : SetDesc ; | |
| CASE type: ElementType OF | |
| idel : ident : IdentDesc | | |
| tokel, | |
| litel : string: Name | |
| END | |
| END ; | |
| (* note that epsilon refers to whether we can satisfy this component part | |
| of a sentance without consuming a token. Reachend indicates we can get | |
| to the end of the sentance without consuming a token. | |
| For expression, statement, productions, terms: the epsilon value should | |
| equal the reachend value but for factors the two may differ. | |
| *) | |
| FollowDesc = POINTER TO followdesc ; | |
| followdesc = RECORD | |
| calcfollow : BOOLEAN ; (* have we solved the follow set yet? *) | |
| follow : SetDesc ; (* the follow set *) | |
| reachend : TraverseResult ; (* can we see the end of the sentance (due to multiple epsilons) *) | |
| epsilon : TraverseResult ; (* potentially no token may be consumed within this component of the sentance *) | |
| line : CARDINAL ; | |
| END ; | |
| TermDesc = POINTER TO termdesc ; | |
| ExpressionDesc = POINTER TO expressiondesc ; | |
| expressiondesc = RECORD | |
| term : TermDesc ; | |
| followinfo: FollowDesc ; | |
| line : CARDINAL ; | |
| END ; | |
| StatementDesc = POINTER TO statementdesc ; | |
| statementdesc = RECORD | |
| ident : IdentDesc ; | |
| expr : ExpressionDesc ; | |
| followinfo : FollowDesc ; | |
| line : CARDINAL ; | |
| END ; | |
| CodeHunk = POINTER TO codehunk ; | |
| codehunk = RECORD | |
| codetext : ARRAY [0..MaxCodeHunkLength] OF CHAR ; | |
| next : CodeHunk ; | |
| END ; | |
| CodeDesc = POINTER TO codedesc ; | |
| codedesc = RECORD | |
| code : CodeHunk ; | |
| indent : CARDINAL ; (* column of the first % *) | |
| line : CARDINAL ; | |
| END ; | |
| FactorType = (id, lit, sub, opt, mult, m2) ; | |
| FactorDesc = POINTER TO factordesc ; | |
| factordesc = RECORD | |
| followinfo: FollowDesc ; | |
| next : FactorDesc ; (* chain of successive factors *) | |
| line : CARDINAL ; | |
| pushed : FactorDesc ; (* chain of pushed code factors *) | |
| CASE type: FactorType OF | |
| id : ident : IdentDesc | | |
| lit : string: Name | | |
| sub, | |
| opt, | |
| mult: expr : ExpressionDesc | | |
| m2 : code : CodeDesc ; | |
| END | |
| END ; | |
| termdesc = RECORD | |
| factor : FactorDesc ; | |
| next : TermDesc ; (* chain of alternative terms *) | |
| followinfo: FollowDesc ; | |
| line : CARDINAL ; | |
| END ; | |
| productiondesc = RECORD | |
| next : ProductionDesc ; (* the chain of productions *) | |
| statement : StatementDesc ; | |
| first : SetDesc ; (* the first set *) | |
| firstsolved : BOOLEAN ; | |
| followinfo : FollowDesc ; | |
| line : CARDINAL ; | |
| description : Name ; | |
| END ; | |
| DoProcedure = PROCEDURE (ProductionDesc) ; | |
| VAR | |
| f: FactorDesc ; | |
| BEGIN | |
| f^.type := m2 | |
| END tinyvarient6. |