This table provides a guideline as how to interpret the following two tables.
| Syntax | Description |
|---|---|
| | | Or |
| * | Zero or more |
| + | One or more |
| {} | Grouping a subexpression |
| [] | Optional subexpression |
| Comment Info | Appear in italics |
| Tokens | Appear in ALL CAPITALS |
| Key Words | Appear in bold |
SIF is an ASCII file format which is similar lexically to C code. SIF does not have a preprocessor, and it does not have any macro text facilities. SIF is a static scoped language, like Pascal.
| Token | Description |
|---|---|
| {" ", "\t", "\n"} | White space is used as separators in SIF and then ignored |
| (* ... *) | Multiline comments can be nested |
| # ... \n | Single line comments can be used with multiline comments |
| INT | positive or negative constant integer |
| REAL | positive or negative number in decimal notation of the form [-]mmm.ddd |
| ( ) | Delimit expression as in LISP |
| color | A volume or surface property |
| constellation | A group of solids whose positions relative to each other should be maintained. |
| desired_accuracy | The accuracy with which the designer wants the part manufactured. |
| difference | A boolean difference operation |
| e | Exponential or Scientific notation for a value |
| inches | Sets units to inches |
| intersection | A boolean intersection operation |
| mm | Sets units to millimeters |
| rgb | Specification of color as an rgb triple |
| shell | A closed surface |
| SIF_SFF | Header stating that this is a SIF SFF type file |
| solid | A set of shells enclosing volume(s) |
| surface | A set of 2D elements |
| triangles | A list of triangles (possibly contained in surfaces) |
| t | A triangle |
| union | A boolean union operation |
| units | Sets the units for the file |
| vertices | A list of vertices |
| v | A vertex |
| Nonterminal | -> | Production |
|---|---|---|
| part | -> | ( SIF_SFF version:INT release:INT units accuracy solid_list ) |
| units | -> | ( units units_setting ) |
| units_setting | -> | mm | inches |
| accuracy | -> | [ ( desired_accuracy value ) ] |
| solid_list | -> | { constellation | solid } + |
| constellation | -> | ( constellation solid+ ) |
| solid | -> | ( solid volume_property* shell_set+ ) |
| shell_set | -> | boolean | shell |
| shell | -> | ( shell vertex_array open_2d_list ) |
| boolean | -> | intersection | union | difference |
| union | -> | ( union shell_set+ ) |
| intersection | -> | ( intersection shell_set+ ) |
| difference | -> | ( difference shell_set+ ) |
| surface | -> | ( surface surface_property* open_2d+ ) |
| open_2d_list | -> | ( triangles number:INT open_2d+ ) |
| open_2d | -> | surface | triangle |
| triangle | -> | ( t vertex index:INT vertex index:INT vertex index:INT ) |
| vertex_array | -> | ( vertices number:INT vertex+ ) |
| vertex | -> | ( v x:value y:value [ z=0:value [ w=1:value ] ] ) | surface_property | -> | ( color color_setting ) |
| (user extension) | volume_property | -> | ( color color_setting ) |
| (user extension) | ||
| color_setting | -> | ( rgb R:value G:value B:value ) |
| value | -> | INT |
| REAL | ||
| ( e mantissa:INT exponent:INT ) |
accuracy , boolean , color_setting , difference , intersection , open_2d_list , open_2d , part , shell_set , shell , solid , solid_list , surface_property , surface , triangle , union , units_setting , units , value , vertex_array , vertex , volume_property
This page is maintained by
Sara McMains
E-mail: sara@cs.berkeley.edu
Last modified: 12/20/99
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