| 1 | (* HCoop Domtool (http://hcoop.sourceforge.net/) |
| 2 | * Copyright (c) 2006, Adam Chlipala |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version 2 |
| 7 | * of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| 17 | *) |
| 18 | |
| 19 | (* Configuration language abstract syntax *) |
| 20 | |
| 21 | structure Ast = struct |
| 22 | |
| 23 | open DataStructures |
| 24 | |
| 25 | (* A description of a predicate on configuration block stacks *) |
| 26 | datatype context' = |
| 27 | CRoot |
| 28 | (* The stack is empty. *) |
| 29 | | CConst of string |
| 30 | (* The given context name is on top of the stack. *) |
| 31 | | CPrefix of context |
| 32 | (* Some prefix of the stack matches the context. *) |
| 33 | | CNot of context |
| 34 | (* The context does not match. *) |
| 35 | | CAnd of context * context |
| 36 | (* Both contexts match. *) |
| 37 | withtype context = context' * position |
| 38 | |
| 39 | datatype typ' = |
| 40 | TBase of string |
| 41 | (* Base type *) |
| 42 | | TList of typ |
| 43 | (* SML 'a list *) |
| 44 | | TArrow of typ * typ |
| 45 | (* SML -> *) |
| 46 | | TAction of context * record * record |
| 47 | (* An action that: |
| 48 | * - Is valid in the given context |
| 49 | * - Expects an environment compatible with the first record |
| 50 | * - Modifies it according to the second record *) |
| 51 | withtype typ = typ' * position |
| 52 | and record = typ StringMap.map |
| 53 | |
| 54 | datatype exp' = |
| 55 | EInt of int |
| 56 | (* Constant integer *) |
| 57 | | EString of string |
| 58 | (* Constant string *) |
| 59 | | EList of exp list |
| 60 | (* Basic list constructor *) |
| 61 | |
| 62 | | ELam of string * typ * exp |
| 63 | (* Function abstraction *) |
| 64 | | EVar of string |
| 65 | (* Variable bound by a function *) |
| 66 | | EApp of exp * exp |
| 67 | (* Function application *) |
| 68 | |
| 69 | | ESet of string * exp |
| 70 | (* Set an environment variable *) |
| 71 | | EEnv of string |
| 72 | (* Get an environment variable *) |
| 73 | | ESeq of exp list |
| 74 | (* Monad sequencer; execute a number of commands in order *) |
| 75 | | ELocal of exp |
| 76 | (* Local execution; execute the action and then restore the previous |
| 77 | * environment. *) |
| 78 | withtype exp = exp' * position |
| 79 | |
| 80 | |
| 81 | end |