uspace/lib/bithenge/expression.h

   1 /*
   2  * Copyright (c) 2012 Sean Bartell
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup bithenge
  30  * @{
  31  */
  32 /**
  33  * @file
  34  * Expressions.
  35  */
  36
  37 #ifndef BITHENGE_EXPRESSION_H_
  38 #define BITHENGE_EXPRESSION_H_
  39
  40 #include "blob.h"
  41 #include "transform.h"
  42 #include "tree.h"
  43
  44 /** An expression that calculates a value given a scope. */
  45 typedef struct {
  46         /** @privatesection */
  47         const struct bithenge_expression_ops *ops;
  48         unsigned int refs;
  49 } bithenge_expression_t;
  50
  51 /** Operations provided by an expression. */
  52 typedef struct bithenge_expression_ops {
  53         /** @copydoc bithenge_expression_t::bithenge_expression_evaluate */
  54         int (*evaluate)(bithenge_expression_t *self, bithenge_scope_t *scope,
  55             bithenge_node_t **out);
  56         /** Destroy the expression.
  57          * @param self The expression. */
  58         void (*destroy)(bithenge_expression_t *self);
  59 } bithenge_expression_ops_t;
  60
  61 /** Increment an expression's reference count.
  62  * @param self The expression to reference. */
  63 static inline void bithenge_expression_inc_ref(bithenge_expression_t *self)
  64 {
  65         assert(self);
  66         self->refs++;
  67 }
  68
  69 /** Decrement an expression's reference count and free it if appropriate.
  70  * @param self The expression to dereference, or NULL. */
  71 static inline void bithenge_expression_dec_ref(bithenge_expression_t *self)
  72 {
  73         if (!self)
  74                 return;
  75         assert(self->ops);
  76         assert(self->refs > 0);
  77         if (--self->refs == 0)
  78                 self->ops->destroy(self);
  79 }
  80
  81 /** Evaluate an expression. Takes ownership of nothing.
  82  * @memberof bithenge_expression_t
  83  * @param self The expression.
  84  * @param scope The scope.
  85  * @param[out] out Where the output tree will be stored.
  86  * @return EOK on success or an error code from errno.h. */
  87 static inline int bithenge_expression_evaluate(bithenge_expression_t *self,
  88     bithenge_scope_t *scope, bithenge_node_t **out)
  89 {
  90         assert(self);
  91         assert(self->ops);
  92         return self->ops->evaluate(self, scope, out);
  93 }
  94
  95 /** The binary operators supported by @a bithenge_binary_expression(). */
  96 typedef enum {
  97         BITHENGE_EXPRESSION_INVALID_BINARY_OP,
  98
  99         BITHENGE_EXPRESSION_ADD,
 100         BITHENGE_EXPRESSION_SUBTRACT,
 101         BITHENGE_EXPRESSION_MULTIPLY,
 102         BITHENGE_EXPRESSION_INTEGER_DIVIDE,
 103         BITHENGE_EXPRESSION_MODULO,
 104
 105         BITHENGE_EXPRESSION_LESS_THAN,
 106         BITHENGE_EXPRESSION_GREATER_THAN,
 107         BITHENGE_EXPRESSION_LESS_THAN_OR_EQUAL,
 108         BITHENGE_EXPRESSION_GREATER_THAN_OR_EQUAL,
 109         BITHENGE_EXPRESSION_EQUALS,
 110         BITHENGE_EXPRESSION_NOT_EQUALS,
 111
 112         BITHENGE_EXPRESSION_AND,
 113         BITHENGE_EXPRESSION_OR,
 114
 115         BITHENGE_EXPRESSION_MEMBER,
 116         BITHENGE_EXPRESSION_CONCAT,
 117 } bithenge_binary_op_t;
 118
 119 int bithenge_init_expression(bithenge_expression_t *,
 120     const bithenge_expression_ops_t *);
 121 int bithenge_binary_expression(bithenge_expression_t **, bithenge_binary_op_t,
 122     bithenge_expression_t *, bithenge_expression_t *);
 123 int bithenge_in_node_expression(bithenge_expression_t **);
 124 int bithenge_current_node_expression(bithenge_expression_t **);
 125 int bithenge_param_expression(bithenge_expression_t **, int);
 126 int bithenge_const_expression(bithenge_expression_t **, bithenge_node_t *);
 127 int bithenge_scope_member_expression(bithenge_expression_t **,
 128     bithenge_node_t *);
 129 int bithenge_subblob_expression(bithenge_expression_t **,
 130     bithenge_expression_t *, bithenge_expression_t *, bithenge_expression_t *,
 131     bool);
 132 int bithenge_param_wrapper(bithenge_transform_t **, bithenge_transform_t *,
 133     bithenge_expression_t **);
 134 int bithenge_expression_transform(bithenge_transform_t **,
 135     bithenge_expression_t *);
 136 int bithenge_inputless_transform(bithenge_transform_t **,
 137     bithenge_expression_t *);
 138
 139 int bithenge_concat_blob(bithenge_node_t **, bithenge_blob_t *,
 140     bithenge_blob_t *);
 141 int bithenge_concat_blob_lazy(bithenge_node_t **, bithenge_blob_t *,
 142     bithenge_expression_t *, bithenge_scope_t *);
 143
 144 #endif
 145
 146 /** @}
 147  */