1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2016, VU University Amsterdam 7 All rights reserved. 8 9 Redistribution and use in source and binary forms, with or without 10 modification, are permitted provided that the following conditions 11 are met: 12 13 1. Redistributions of source code must retain the above copyright 14 notice, this list of conditions and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in 18 the documentation and/or other materials provided with the 19 distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 POSSIBILITY OF SUCH DAMAGE. 33*/ 34 35:- module(r_term, 36 [ r_expression//2, % +Expression, -Assignments 37 38 op(400, yfx, $), 39 op(100, yf, []) 40 ]). 41:- use_module(r_grammar). 42:- use_module(r_expand_dot). 43:- use_module(library(error)). 44:- use_module(library(dcg/basics)).
true and false are mapped to TRUE and FALSE.Left$Right is translated as is.X[I,...] is translated as is. Empty
elements in the index, e.g., the R expression a[,3]
can be written as `a['',3]`, `a[-,3] or a[*,3]`.+, -, *, /, mod, '%%', ^,
>=, >, ==, <, <=, =<, \=, '!=', :, <-Expr1,Expr2 is translated into two R statements separated
by a newline.
This library loads r_expand_dot.pl, which uses the `.` infix
operator to make a.b and a.b() valid syntax.
87r_expression(Term, Assignments) --> 88 { Ctx = r{v:v{tmpvar:0, assignments:[]}, priority:999} }, 89 r_expr(Term, Ctx), 90 { Assignments = Ctx.v.assignments }. 91 92r_expr(Var, _) --> 93 { var(Var), !, 94 instantiation_error(Var) 95 }. 96r_expr(true, _) --> !, "TRUE". 97r_expr(false, _) --> !, "FALSE". 98r_expr(Identifier, _) --> 99 { atom(Identifier) 100 }, !, 101 ( { r_identifier(Identifier) } 102 -> atom(Identifier) 103 ; { atom_codes(Identifier, Codes) }, 104 "`", r_string_codes(Codes, 0'`), "`" 105 ). 106r_expr(String, _) --> 107 { string(String), 108 string_codes(String, Codes) 109 }, !, 110 "\"", r_string_codes(Codes, 0'"), "\"". 111r_expr(+Atom, _) --> 112 { atomic(Atom), !, 113 atom_codes(Atom, Codes) 114 }, 115 "\"", r_string_codes(Codes, 0'"), "\"". 116r_expr(Number, _) --> 117 { number(Number) }, !, 118 number(Number). 119r_expr(List, Ctx) --> 120 { is_list(List), !, 121 assignment(List, Ctx, Var) 122 }, 123 atom(Var). 124r_expr(Left$Right, Ctx) --> !, 125 r_expr(Left, Ctx), "$", r_expr(Right, Ctx). 126r_expr([](Index, Array), Ctx) --> !, 127 r_expr(Array, Ctx), 128 "[", r_index(Index, Ctx.put(priority, 999)), "]". 129r_expr((A,B), Ctx) --> !, 130 r_expr(A, Ctx), "\n", 131 r_expr(B, Ctx). 132r_expr(Compound, Ctx) --> 133 { compound(Compound), 134 compound_name_arguments(Compound, Name, Args), 135 r_identifier(Name), ! 136 }, 137 atom(Name), "(", r_arguments(Args, Ctx.put(priority, 999)), ")". 138r_expr(Compound, Ctx) --> 139 { compound(Compound), 140 compound_name_arguments(Compound, Name, [Left,Right]), 141 r_infix_op(Name, RName, Pri, Ass), !, 142 lr_pri(Pri, Ass, LPri, RPri) 143 }, 144 ( { Ctx.priority >= Pri } 145 -> r_expr(Left, Ctx.put(priority,LPri)), 146 " ", atom(RName), " ", 147 r_expr(Right, Ctx.put(priority,RPri)) 148 ; "(", 149 r_expr(Left, Ctx.put(priority,LPri)), 150 " ", atom(RName), " ", 151 r_expr(Right, Ctx.put(priority,RPri)), 152 ")" 153 ). 154 155% Support for signs + and - 156r_expr(Compound, Ctx) --> 157 { compound(Compound), 158 compound_name_arguments(Compound, Name, [Right]), 159 r_prefix_op(Name, RName, Pri, Ass), !, 160 r_pri(Pri, Ass, RPri) 161 }, 162 ( { Ctx.priority >= Pri } 163 -> atom(RName), " ", 164 r_expr(Right, Ctx.put(priority,RPri)) 165 ; "(", 166 atom(RName), " ", 167 r_expr(Right, Ctx.put(priority,RPri)), 168 ")" 169 ). 170 171r_arguments([], _) --> "". 172r_arguments([H|T], Ctx) --> 173 r_expr(H, Ctx), 174 ( {T==[]} 175 -> "" 176 ; ", ", 177 r_arguments(T, Ctx) 178 ). 179 180r_index([], _) --> "". 181r_index([H|T], Ctx) --> 182 r_index_elem(H, Ctx), 183 ( {T==[]} 184 -> "" 185 ; ",", 186 r_index(T, Ctx) 187 ). 188 189r_index_elem(Var, _) --> 190 { var(Var), 191 instantiation_error(Var) 192 }. 193r_index_elem('', _) --> 194 !. 195r_index_elem(-, _) --> 196 !. 197r_index_elem(*, _) --> 198 !. 199r_index_elem(Expr, Ctx) --> 200 r_expr(Expr, Ctx). 201 202assignment(Data, Ctx, Var) :- 203 Vars = Ctx.v, 204 _{tmpvar:I, assignments:A0} :< Vars, 205 atom_concat('Rserve.tmp.', I, Var), 206 I2 is I + 1, 207 b_set_dict(tmpvar, Vars, I2), 208 b_set_dict(assignments, Vars, [Var=Data|A0]).
215r_string_codes([], _) --> []. 216r_string_codes([H|T], Esc) --> r_string_code(H, Esc), r_string_codes(T, Esc). 217 218r_string_code(0, _) --> !, 219 { domain_error(r_string_code, 0) }. 220r_string_code(C, C) --> !, "\\", [C]. 221r_string_code(C, _) --> [C].
229r_infix_op(+, +, 500, yfx). 230r_infix_op(-, -, 500, yfx). 231r_infix_op(*, *, 400, yfx). 232r_infix_op(/, /, 400, yfx). 233r_infix_op(mod, '%%', 400, yfx). 234r_infix_op('%%', '%%', 400, yfx). 235r_infix_op(^, ^, 200, xfy). 236 237r_infix_op(>=, >=, 700, xfx). 238r_infix_op(>, >, 700, xfx). 239r_infix_op(==, ==, 700, xfx). 240r_infix_op(<, <, 700, xfx). 241r_infix_op(<=, <=, 700, xfx). 242r_infix_op(=<, <=, 700, xfx). 243r_infix_op(\=, '!=', 700, xfx). 244r_infix_op('!=', '!=', 700, xfx). 245 246r_infix_op(:, :, 100, xfx). % range 247 248r_infix_op(<-, <-, 900, xfx). 249r_infix_op(=, =, 900, xfx). 250 251lr_pri(Pri, xfx, APri, APri) :- !, APri is Pri - 1. 252lr_pri(Pri, xfy, APri, Pri) :- !, APri is Pri - 1. 253lr_pri(Pri, yfx, Pri, APri) :- !, APri is Pri - 1.
258r_prefix_op(-, -, 200, fy). 259 260r_pri(Pri, fx, APri) :- !, APri is Pri - 1. 261r_pri(Pri, fy, Pri)
Translate a Prolog term into an R expression
This module deals with representing an R expression as a Prolog term. The non-terminal r_expression//2 translates the Prolog term into a string that can be sent to R.
The design is inspired by real from Nicos Angelopoulos. */