Yu
Yu (羽) is a simple system programming language.
Documentations
- Tutorial: 简体中文版 (GitHub), 简体中文版 (Gitee).
Visit YuLang-doc for more details.
Features
- Block expression
- Modules and
importstatement - Type deduction and reference type
- Inline function/variable/constant
- Function/operator overloading
- Operator-formed identifier
- Dot function and infix function
- Iterator
Examples: Hello World
C style:
import sys.unistd
import sys.string
extern def main(argc: i32, argv: u8**): i32 {
let hello = "Hello world!\n", len = strlen(hello)
write(FD_STDOUT, hello, len)
0
}
OOP-like style (but not real OOP):
import sys.unistd
import sys.string
struct Output {}
def println(this: Output&, str: u8*) {
write(FD_STDOUT, str, strlen(str))
write(FD_STDOUT, "\n", 1 as u32)
}
let out = [Output] {}
extern def main(argc: i32, argv: u8**): i32 {
out.println("Hello world!")
0
}
C++ cout style with custom operator <<<:
import io
extern def main(argc: i32, argv: u8**): i32 {
out <<< "Hello world! " <<< 123 <<< '\n'
0
}
Natural language style (see natural.yu):
extern def main(argc: i32, argv: u8**): i32 {
// be polite
please put "Hello world! " and 123 to stdout
thanks
}
Building from Source
Before building YuLang compiler, please make sure you have installed the following dependencies:
cmake3.13 or laterllvm10.0 or later- C++ compiler supporting C++17
You may want to check the toolchain configuration in toolchain.mk. Then you can build this repository by executing the following command lines:
$ git clone --recursive https://github.com/MaxXSoft/YuLang.git
$ cd YuLang
$ mkdir build
$ cd build
$ cmake .. && make -j8
EBNF of Yu
program ::= {line};
line ::= stmt {";" stmt} [";"];
stmt ::= var_def | let_def | fun_def | declare
| ty_alias | struct | enum | import;
var_def ::= property "var" var_elem {"," var_elem};
let_def ::= property "let" let_elem {"," let_elem};
fun_def ::= property "def" [id | bin_op | unary_op]
"(" [arg_list] ")" [":" type] block;
declare ::= property "declare" ["var"] id ":" type;
ty_alias ::= property "type" id "=" type;
struct ::= property "struct" id "{" arg_list [","] "}";
enum ::= property "enum" id [":" type] "{" enum_list "}";
import ::= property "import" id {"." id};
property ::= ["public" | "extern" | "inline"]
var_elem ::= id [":" type] ["=" expr];
let_elem ::= id [":" type] "=" expr;
arg_list ::= id ":" type ["," arg_list];
enum_list ::= id ["=" expr] ["," enum_list] [","];
block ::= "{" {blk_line} "}";
blk_line ::= blk_stmt {";" blk_stmt} [";"];
blk_stmt ::= var_def | let_def | declare | ty_alias | struct
| enum | if_else | when | while | for_in
| asm | control | expr;
if_else ::= "if" expr block ["else" (if_else | block)];
when ::= "when" expr "{" when_elem {when_elem} ["else" block] "}";
while ::= "while" expr block;
for_in ::= "for" id "in" expr block;
asm ::= "asm" "{" string {string} "}";
control ::= "break" | "continue" | ("return" [expr]);
when_elem ::= expr {"," expr} block;
expr ::= binary {id binary};
binary ::= cast {bin_op cast};
cast ::= unary {"as" type};
unary ::= [unary_op] factor | "sizeof" type;
factor ::= value | block | if_else | when
| index | fun_call | access | "(" expr ")";
bin_op ::= "+" | "-" | "*" | "/" | "%" | "&"
| "|" | "^" | "&&" | "||" | "<<" | ">>"
| "==" | "!=" | "<" | "<=" | ">" | ">="
| "=" | "+=" | "-=" | "*=" | "/=" | "%="
| "&=" | "|=" | "^=" | "<<=" | ">>=" | ".";
unary_op ::= "+" | "-" | "!" | "~" | "*" | "&";
index ::= factor "[" expr "]";
fun_call ::= factor "(" [expr {"," expr}] ")";
access ::= factor "." id ["(" [expr {"," expr}] ")"];
value ::= INT_VAL | FLOAT_VAL | CHAR_VAL | id
| string | bool | null_ptr | val_init;
id ::= ID_VAL;
string ::= STR_VAL;
bool ::= "true" | "false";
null_ptr ::= "null";
val_init ::= "[" type "]" "{" [expr {"," expr} [","]] "}";
type ::= (prim_type | id | pointer | array | ref | func) ["volatile"];
prim_type ::= "i8" | "i16" | "i32" | "i64" | "isize" | "u8" | "u16"
| "u32" | "u64" | "usize" | "f32" | "f64" | "bool";
pointer ::= type ["var"] "*";
array ::= type "[" expr "]";
ref ::= type ["var"] "&";
func ::= "(" [type {"," type}] ")" [":" type];Changelog
See CHANGELOG.md
License
Copyright (C) 2010-2020 MaxXing. License GPLv3.