1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
`Sass_Values` are used to pass values and their types between the implementer
and LibSass. Sass knows various different value types (including nested arrays
and hash-maps). If you implement a binding to another programming language, you
have to find a way to [marshal][1] (convert) `Sass_Values` between the target
language and C. `Sass_Values` are currently only used by custom functions, but
it should also be possible to use them without a compiler context.
[1]: https://en.wikipedia.org/wiki/Marshalling_%28computer_science%29
### Basic Usage
```C
#include "sass/values.h"
```
```C
// Type for Sass values
enum Sass_Tag {
SASS_BOOLEAN,
SASS_NUMBER,
SASS_COLOR,
SASS_STRING,
SASS_LIST,
SASS_MAP,
SASS_NULL,
SASS_ERROR,
SASS_WARNING
};
// Tags for denoting Sass list separators
enum Sass_Separator {
SASS_COMMA,
SASS_SPACE,
// only used internally to represent a hash map before evaluation
// otherwise we would be too early to check for duplicate keys
SASS_HASH
};
// Value Operators
enum Sass_OP {
AND, OR, // logical connectives
EQ, NEQ, GT, GTE, LT, LTE, // arithmetic relations
ADD, SUB, MUL, DIV, MOD, // arithmetic functions
NUM_OPS // so we know how big to make the op table
};
```
### Sass Value API
```C
// Forward declaration
union Sass_Value;
// Creator functions for all value types
union Sass_Value* sass_make_null (void);
union Sass_Value* sass_make_boolean (bool val);
union Sass_Value* sass_make_string (const char* val);
union Sass_Value* sass_make_qstring (const char* val);
union Sass_Value* sass_make_number (double val, const char* unit);
union Sass_Value* sass_make_color (double r, double g, double b, double a);
union Sass_Value* sass_make_list (size_t len, enum Sass_Separator sep, bool is_bracketed);
union Sass_Value* sass_make_map (size_t len);
union Sass_Value* sass_make_error (const char* msg);
union Sass_Value* sass_make_warning (const char* msg);
// Generic destructor function for all types
// Will release memory of all associated Sass_Values
// Means we will delete recursively for lists and maps
void sass_delete_value (union Sass_Value* val);
// Make a deep cloned copy of the given sass value
union Sass_Value* sass_clone_value (const union Sass_Value* val);
// Stringify a Sass_Values and also return the result as a Sass_Value (of type STRING)
union Sass_Value* sass_value_stringify (const union Sass_Value* a, bool compressed, int precision);
// Execute an operation for two Sass_Values and return the result as a Sass_Value too
union Sass_Value* sass_value_op (enum Sass_OP op, const union Sass_Value* a, const union Sass_Value* b);
// Return the sass tag for a generic sass value
// Check is needed before accessing specific values!
enum Sass_Tag sass_value_get_tag (const union Sass_Value* v);
// Check value to be of a specific type
// Can also be used before accessing properties!
bool sass_value_is_null (const union Sass_Value* v);
bool sass_value_is_number (const union Sass_Value* v);
bool sass_value_is_string (const union Sass_Value* v);
bool sass_value_is_boolean (const union Sass_Value* v);
bool sass_value_is_color (const union Sass_Value* v);
bool sass_value_is_list (const union Sass_Value* v);
bool sass_value_is_map (const union Sass_Value* v);
bool sass_value_is_error (const union Sass_Value* v);
bool sass_value_is_warning (const union Sass_Value* v);
// Getters and setters for Sass_Number
double sass_number_get_value (const union Sass_Value* v);
void sass_number_set_value (union Sass_Value* v, double value);
const char* sass_number_get_unit (const union Sass_Value* v);
void sass_number_set_unit (union Sass_Value* v, char* unit);
// Getters and setters for Sass_String
const char* sass_string_get_value (const union Sass_Value* v);
void sass_string_set_value (union Sass_Value* v, char* value);
bool sass_string_is_quoted(const union Sass_Value* v);
void sass_string_set_quoted(union Sass_Value* v, bool quoted);
// Getters and setters for Sass_Boolean
bool sass_boolean_get_value (const union Sass_Value* v);
void sass_boolean_set_value (union Sass_Value* v, bool value);
// Getters and setters for Sass_Color
double sass_color_get_r (const union Sass_Value* v);
void sass_color_set_r (union Sass_Value* v, double r);
double sass_color_get_g (const union Sass_Value* v);
void sass_color_set_g (union Sass_Value* v, double g);
double sass_color_get_b (const union Sass_Value* v);
void sass_color_set_b (union Sass_Value* v, double b);
double sass_color_get_a (const union Sass_Value* v);
void sass_color_set_a (union Sass_Value* v, double a);
// Getter for the number of items in list
size_t sass_list_get_length (const union Sass_Value* v);
// Getters and setters for Sass_List
enum Sass_Separator sass_list_get_separator (const union Sass_Value* v);
void sass_list_set_separator (union Sass_Value* v, enum Sass_Separator value);
bool sass_list_get_is_bracketed (const union Sass_Value* v);
void sass_list_set_is_bracketed (union Sass_Value* v, bool value);
// Getters and setters for Sass_List values
union Sass_Value* sass_list_get_value (const union Sass_Value* v, size_t i);
void sass_list_set_value (union Sass_Value* v, size_t i, union Sass_Value* value);
// Getter for the number of items in map
size_t sass_map_get_length (const union Sass_Value* v);
// Getters and setters for Sass_Map keys and values
union Sass_Value* sass_map_get_key (const union Sass_Value* v, size_t i);
void sass_map_set_key (union Sass_Value* v, size_t i, union Sass_Value*);
union Sass_Value* sass_map_get_value (const union Sass_Value* v, size_t i);
void sass_map_set_value (union Sass_Value* v, size_t i, union Sass_Value*);
// Getters and setters for Sass_Error
char* sass_error_get_message (const union Sass_Value* v);
void sass_error_set_message (union Sass_Value* v, char* msg);
// Getters and setters for Sass_Warning
char* sass_warning_get_message (const union Sass_Value* v);
void sass_warning_set_message (union Sass_Value* v, char* msg);
```
### More links
- [Sass Value Example](api-value-example.md)
- [Sass Value Internal](api-value-internal.md)
|
