| 1 | /* Copyright (C) 2000, 2001, 2006, 2008, 2009, 2011, 2012 Free Software Foundation, Inc. |
| 2 | * |
| 3 | * This library is free software; you can redistribute it and/or |
| 4 | * modify it under the terms of the GNU Lesser General Public License |
| 5 | * as published by the Free Software Foundation; either version 3 of |
| 6 | * the License, or (at your option) any later version. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * Lesser General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public |
| 14 | * License along with this library; if not, write to the Free Software |
| 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 16 | * 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #ifdef HAVE_CONFIG_H |
| 20 | # include <config.h> |
| 21 | #endif |
| 22 | |
| 23 | #include "libguile/_scm.h" |
| 24 | #include "libguile/eval.h" |
| 25 | #include "libguile/feature.h" |
| 26 | #include "libguile/gc.h" |
| 27 | #include "libguile/numbers.h" |
| 28 | #include "libguile/ports.h" |
| 29 | #include "libguile/root.h" |
| 30 | #include "libguile/strings.h" |
| 31 | #include "libguile/struct.h" |
| 32 | #include "libguile/validate.h" |
| 33 | |
| 34 | #include "libguile/values.h" |
| 35 | |
| 36 | SCM scm_values_vtable; |
| 37 | |
| 38 | /* OBJ must be a values object containing exactly two values. |
| 39 | scm_i_extract_values_2 puts those two values into *p1 and *p2. */ |
| 40 | void |
| 41 | scm_i_extract_values_2 (SCM obj, SCM *p1, SCM *p2) |
| 42 | { |
| 43 | SCM values; |
| 44 | |
| 45 | SCM_ASSERT_TYPE (SCM_VALUESP (obj), obj, SCM_ARG1, |
| 46 | "scm_i_extract_values_2", "values"); |
| 47 | values = scm_struct_ref (obj, SCM_INUM0); |
| 48 | if (scm_ilength (values) != 2) |
| 49 | scm_wrong_type_arg_msg |
| 50 | ("scm_i_extract_values_2", SCM_ARG1, obj, |
| 51 | "a values object containing exactly two values"); |
| 52 | *p1 = SCM_CAR (values); |
| 53 | *p2 = SCM_CADR (values); |
| 54 | } |
| 55 | |
| 56 | static SCM |
| 57 | print_values (SCM obj, SCM pwps) |
| 58 | { |
| 59 | SCM values = scm_struct_ref (obj, SCM_INUM0); |
| 60 | SCM port = SCM_PORT_WITH_PS_PORT (pwps); |
| 61 | scm_print_state *ps = SCM_PRINT_STATE (SCM_PORT_WITH_PS_PS (pwps)); |
| 62 | |
| 63 | scm_puts_unlocked ("#<values ", port); |
| 64 | scm_iprin1 (values, port, ps); |
| 65 | scm_puts_unlocked (">", port); |
| 66 | |
| 67 | return SCM_UNSPECIFIED; |
| 68 | } |
| 69 | |
| 70 | size_t |
| 71 | scm_c_nvalues (SCM obj) |
| 72 | { |
| 73 | if (SCM_LIKELY (SCM_VALUESP (obj))) |
| 74 | return scm_ilength (scm_struct_ref (obj, SCM_INUM0)); |
| 75 | else |
| 76 | return 1; |
| 77 | } |
| 78 | |
| 79 | SCM |
| 80 | scm_c_value_ref (SCM obj, size_t idx) |
| 81 | { |
| 82 | if (SCM_LIKELY (SCM_VALUESP (obj))) |
| 83 | { |
| 84 | SCM values = scm_struct_ref (obj, SCM_INUM0); |
| 85 | size_t i = idx; |
| 86 | while (SCM_LIKELY (scm_is_pair (values))) |
| 87 | { |
| 88 | if (i == 0) |
| 89 | return SCM_CAR (values); |
| 90 | values = SCM_CDR (values); |
| 91 | i--; |
| 92 | } |
| 93 | } |
| 94 | else if (idx == 0) |
| 95 | return obj; |
| 96 | |
| 97 | scm_error (scm_out_of_range_key, |
| 98 | "scm_c_value_ref", |
| 99 | "Too few values in ~S to access index ~S", |
| 100 | scm_list_2 (obj, scm_from_size_t (idx)), |
| 101 | scm_list_1 (scm_from_size_t (idx))); |
| 102 | } |
| 103 | |
| 104 | SCM_DEFINE (scm_values, "values", 0, 0, 1, |
| 105 | (SCM args), |
| 106 | "Delivers all of its arguments to its continuation. Except for\n" |
| 107 | "continuations created by the @code{call-with-values} procedure,\n" |
| 108 | "all continuations take exactly one value. The effect of\n" |
| 109 | "passing no value or more than one value to continuations that\n" |
| 110 | "were not created by @code{call-with-values} is unspecified.") |
| 111 | #define FUNC_NAME s_scm_values |
| 112 | { |
| 113 | long n; |
| 114 | SCM result; |
| 115 | |
| 116 | SCM_VALIDATE_LIST_COPYLEN (1, args, n); |
| 117 | if (n == 1) |
| 118 | result = SCM_CAR (args); |
| 119 | else |
| 120 | result = scm_c_make_struct (scm_values_vtable, 0, 1, SCM_UNPACK (args)); |
| 121 | |
| 122 | return result; |
| 123 | } |
| 124 | #undef FUNC_NAME |
| 125 | |
| 126 | SCM |
| 127 | scm_c_values (SCM *base, size_t nvalues) |
| 128 | { |
| 129 | SCM ret, *walk; |
| 130 | |
| 131 | if (nvalues == 1) |
| 132 | return *base; |
| 133 | |
| 134 | for (ret = SCM_EOL, walk = base + nvalues - 1; walk >= base; walk--) |
| 135 | ret = scm_cons (*walk, ret); |
| 136 | |
| 137 | return scm_values (ret); |
| 138 | } |
| 139 | |
| 140 | void |
| 141 | scm_init_values (void) |
| 142 | { |
| 143 | SCM print = scm_c_define_gsubr ("%print-values", 2, 0, 0, print_values); |
| 144 | |
| 145 | scm_values_vtable = scm_make_vtable (scm_from_locale_string ("pr"), print); |
| 146 | |
| 147 | scm_add_feature ("values"); |
| 148 | |
| 149 | #include "libguile/values.x" |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | Local Variables: |
| 154 | c-file-style: "gnu" |
| 155 | End: |
| 156 | */ |