Based on the Oberon-07 programming language designed by the late Niklaus Wirth.
This is designed to be a language to teach compiler development with.
Meaning behind the name:
- Titania is the wife of Oberon (Fairy King) in Shakespeare's A Midsummer Night's Dream
- https://en.wikipedia.org/wiki/Titania_(A_Midsummer_Night%27s_Dream)
- This is just a codename, and probably not final for this teaching language
module = "module" ident ";" [import_list] decl_sequence
["begin" stmt_sequence] "end" [";"].
import_list = "import" import_decl {"," import_decl} ";".
decl_sequence = ["const" {const_decl ";"}]
["type" {type_decl ";"}]
["var" {var_decl ";"}]
[{proc_decl ";"}].
const_decl = ident "=" const_expr.
type_decl = ident "="" struct_type.
var_decl = ident_list ":" type.
proc_decl = "proc" ident [formal_parameters] ";" proc_body.
proc_body = decl_sequence ["begin" stmt_sequence] ["return" expr] "end".
const_expr = expr.
expr = simple_expr {relation simple_expr}.
simple_expr = ["+" | "-"] unary_expr {add_operator unary_expr}.
unary_expr = ["+" | "-"] term.
term = factor {mul_operator factor}.
factor = integer | real | string | nil | true | false | set |
"(" expr ")" | "not" expr | designator.
element = expr [".." expr].
ident_list = ident {"," ident}.
qual_ident = [ident "."] ident.
struct_type = array_type | record_type | pointer_type | proc_type.
array_type = "["" const_expr {"," const_expr} "]" type.
record_type = "record" ["(" qual_ident ")"] [field_list_sequence] "end".
pointer_type = "^" type.
proc_type = "proc" formal_parameters.
field_list = ["using"] ident_list ":" type.
formal_parmeters = "(" [fp_section {";" fp_section}] [";"] ")".
formal_type = "[" "]" qual_ident.
stmt_sequence = stmt {";" stmt} [";"].
stmt = [assignment | proc_call | if_stmt | case_stmt | while_stmt | repeat_stmt | for_stmt ].
assignment = designator ":=" expr
if_stmt = "if" expr "then" stmt_sequence
{"elseif" expr "then" stmt_sequence}
["else" stmt_sequence]
"end".
case_stmt = "case" expr "of" case {"|" case} "end".
case = [case_label_list ":" stmt_sequence].
case_list = label_range {"," label_range}.
label_range = label [".." label].
label = integer | string | qual_ident.
while_stmt = "while" expr "then" stmt_sequence
{"elseif" expr "then" stmt_sequence}
"end".
repeat_stmt = "repeat" stmt_sequence "until" expr.
for_stmt = "for" ident ":=" expr "to" expr ["by" const_expr] "then" stmt_sequence "end".
designator = qual_ident {selector}.
selector = "." ident |
"[" expr_list "]" |
"^" |
"(" [expr_list] ")".
expr_list = expr {"," expr}.
add_operator = "+" | "-" | "xor" | "or".
mul_operator = "*" | "/" | "%" | "and".
relation = "=" | "<>" | "<" | "<=" | ">" | ">=" | "in" | "is".
and else if nil record true while
begin elseif import not repeat type xor
by end in of return until
case false is or then using
const for module proc to var
+ . ( ) = <>
- , [ ] < <=
* ; { } > >=
/ | := : ..
% ^
When a newline is seen after the following token kind, a semicolon is inserted, otherwise no semicolon is inserted:
- Identifiers
- Integer, Real, String, Boolean literals
nil^),],}end
Note: These will be added to as the compiler develops
abs(x) - absolute value of
lsh(x, y) - logical shift left
ash(x, y) - arithmetic shift right
ror(x, y) - rotate right
chr(i) - convert int to char
ord(c) - convert char to int
inc(x) - x := x + 1
inc(x, y) - x := x + y
dec(x) - x := x - 1
dec(x, y) - x := x - y
incl(x, y) - include y in set x
excl(x, y) - exclude y in set x
odd(x) - x % 2 = 0
floor(x) - round-down for real
ceil(x) - round-up for real
assert(cond) - assert when cond is false
new(ptr) - allocate memory
delete(ptr) - free memory
addr(x) - address of addressable memory
size_of(x) - size of the type of 'x'
align_of(x) - alignment of the type of 'x'
copy(dst, src, n) - non-overlapping memory copying from `src` to `dst` of `n` bytes
print(...) - variadic print without newline
println(...) - variadic print with newline
len(x) - length of an array 'x'