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1 (* Title: Pure/Tools/value.ML |
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2 Author: Florian Haftmann, TU Muenchen |
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3 |
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4 Generic value command for arbitrary evaluators. |
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5 *) |
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6 |
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7 signature VALUE = |
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8 sig |
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9 val value: Proof.context -> term -> term |
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10 val value_select: string -> Proof.context -> term -> term |
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11 val value_cmd: string option -> string list -> string -> Toplevel.state -> unit |
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12 val add_evaluator: string * (Proof.context -> term -> term) -> theory -> theory |
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13 end; |
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14 |
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15 structure Value : VALUE = |
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16 struct |
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17 |
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18 structure Evaluator = TheoryDataFun( |
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19 type T = (string * (Proof.context -> term -> term)) list; |
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20 val empty = []; |
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21 val copy = I; |
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22 val extend = I; |
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23 fun merge pp = AList.merge (op =) (K true); |
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24 ) |
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25 |
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26 val add_evaluator = Evaluator.map o AList.update (op =); |
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27 |
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28 fun value_select name ctxt = |
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29 case AList.lookup (op =) (Evaluator.get (ProofContext.theory_of ctxt)) name |
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30 of NONE => error ("No such evaluator: " ^ name) |
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31 | SOME f => f ctxt; |
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32 |
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33 fun value ctxt t = let val evaluators = Evaluator.get (ProofContext.theory_of ctxt) |
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34 in if null evaluators then error "No evaluators" |
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35 else let val (evaluators, (_, evaluator)) = split_last evaluators |
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36 in case get_first (fn (_, f) => try (f ctxt) t) evaluators |
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37 of SOME t' => t' |
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38 | NONE => evaluator ctxt t |
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39 end end; |
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40 |
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41 fun value_cmd some_name modes raw_t state = |
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42 let |
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43 val ctxt = Toplevel.context_of state; |
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44 val t = Syntax.read_term ctxt raw_t; |
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45 val t' = case some_name |
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46 of NONE => value ctxt t |
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47 | SOME name => value_select name ctxt t; |
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48 val ty' = Term.type_of t'; |
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49 val ctxt' = Variable.auto_fixes t ctxt; |
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50 val p = PrintMode.with_modes modes (fn () => |
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51 Pretty.block [Pretty.quote (Syntax.pretty_term ctxt' t'), Pretty.fbrk, |
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52 Pretty.str "::", Pretty.brk 1, Pretty.quote (Syntax.pretty_typ ctxt' ty')]) (); |
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53 in Pretty.writeln p end; |
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54 |
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55 local structure P = OuterParse and K = OuterKeyword in |
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56 |
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57 val opt_modes = Scan.optional (P.$$$ "(" |-- P.!!! (Scan.repeat1 P.xname --| P.$$$ ")")) []; |
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58 |
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59 val _ = OuterSyntax.improper_command "value" "evaluate and print term" K.diag |
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60 (Scan.option (P.$$$ "[" |-- P.xname --| P.$$$ "]") -- opt_modes -- P.term |
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61 >> (fn ((some_name, modes), t) => Toplevel.no_timing o Toplevel.keep |
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62 (value_cmd some_name modes t))); |
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63 |
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64 end; (*local*) |
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65 |
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66 end; |