Copyright (c) 2015-2018, the Selfie Project authors. All rights reserved. Please see the AUTHORS file for details. Use of this source code is governed by a BSD license that can be found in the LICENSE file.
Selfie is a project of the Computational Systems Group at the Department of Computer Sciences of the University of Salzburg in Austria. For further information and code please refer to:
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This is the grammar of the C Star (C*) programming language.
C* is a tiny subset of the programming language C. C* features global variable declarations with optional initialization as well as procedures with parameters and local variables. C* has five statements (assignment, while loop, if-then-else, procedure call, and return) and standard arithmetic (+, -, *, /, %) and comparison (==, !=, <, <=, >, >=) operators. C* includes the unary * operator for dereferencing pointers hence the name but excludes data types other than uint64_t and uint64_t*, bitwise and Boolean operators, and many other features. The C* grammar is LL(1) with six keywords and 22 symbols. Whitespace as well as single-line (//) and multi-line (/* to */) comments are ignored.
C* Keywords: uint64_t, void, if, else, while, return
C* Symbols: integer, character, string, identifier, ,, ;, (, ), {, }, +, -, *, /, %, =, ==, !=, <, <=, >, >=
with:
integer = digit { digit } .
character = "'" printable_character "'" .
string = """ { printable_character } """ .
identifier = letter { letter | digit | "_" } .
and:
digit = "0" | ... | "9" .
letter = "a" | ... | "z" | "A" | ... | "Z" .
C* Grammar:
cstar = { type identifier [ "=" [ cast ] [ "-" ] literal ] ";" |
( "void" | type ) identifier procedure } .
type = "uint64_t" [ "*" ] .
cast = "(" type ")" .
literal = integer | character .
procedure = "(" [ variable { "," variable } ] ")"
( ";" | "{" { variable ";" } { statement } "}" ) .
variable = type identifier .
statement = call ";" | while | if | return ";" |
( [ "*" ] identifier | "*" "(" expression ")" )
"=" expression ";" .
call = identifier "(" [ expression { "," expression } ] ")" .
expression = simpleExpression [ ( "==" | "!=" | "<" | ">" | "<=" | ">=" ) simpleExpression ] .
simpleExpression = term { ( "+" | "-" ) term } .
term = factor { ( "*" | "/" | "%" ) factor } .
factor = [ cast ] [ "-" ] [ "*" ]
( identifier | call | literal | string | "(" expression ")" ) .
while = "while" "(" expression ")"
( statement |
"{" { statement } "}" ) .
if = "if" "(" expression ")"
( statement |
"{" { statement } "}" )
[ "else"
( statement |
"{" { statement } "}" ) ] .
return = "return" [ expression ] .