more tokens in the lexer code

This commit is contained in:
hyung-hwan 2021-11-28 17:00:17 +00:00
parent c3a14cbfb7
commit 689346a843
3 changed files with 223 additions and 11 deletions

View File

@ -5,6 +5,7 @@ package body H3.Compilers is
package Utf8 is new H3.Utf8(Standard.Character, S.Rune, Char_Array, S.Rune_Array);
LB_EOF: constant S.Rune_Array := (R.V.Left_Arrow,R.V.UC_E,R.V.UC_O,R.V.UC_F,R.V.Right_Arrow); -- <EOF>
LB_EOL: constant S.Rune_Array := (R.V.Left_Arrow,R.V.UC_E,R.V.UC_O,R.V.UC_L,R.V.Right_Arrow); -- <EOL>
LB_XINCLUDE: constant S.Rune_Array := (R.V.Number_Sign,R.V.LC_I,R.V.LC_N,R.V.LC_C,R.V.LC_L,R.V.LC_U,R.V.LC_D,R.V.LC_E); -- #include
@ -165,7 +166,7 @@ package body H3.Compilers is
Ada.Text_IO.Close (C.Inc.Streams(C.Inc.Top).Handle);
if Check then
if C.Prs.Top /= C.Inc.Streams(C.Inc.Top).Prs_Level + 1 then
raise Syntax_Error with "unblanced inclusion content";
raise Syntax_Error with "unblanced inclusion content";
end if;
end if;
C.Inc.Top := C.Inc.Top - 1;
@ -263,6 +264,16 @@ package body H3.Compilers is
end Got_Token;
function Is_Ident_Starter(Code: in R.Code) return Boolean is
begin
return R.Is_Alnum(Code) or else R.Is_Rune(Code, R.V.Minus_Sign);
end Is_Ident_Starter;
function Is_Ident_Char(Code: in R.Code) return Boolean is
begin
return Is_Ident_Starter(Code) or else R.Is_Rune(Code, R.V.Underline); -- or else R.Is_Rune(C, ...);
end Is_Ident_Char;
procedure Feed_Char_Code (C: in out Compiler; Code: in R.Code) is
begin
<<Start_Over>>
@ -275,10 +286,41 @@ package body H3.Compilers is
End_Token (C, TK_EOF);
-- this procedure doesn't prevent you from feeding more runes
-- after EOF. but it's not desirable to feed more after EOF.
elsif R.Is_Rune(Code, R.V.LF) then -- TODO: support a different EOL scheme
Start_Token (C, LB_EOL);
End_Token (C, TK_EOL);
elsif R.Is_Space(Code) then
-- ignore. carry on
null;
elsif R.Is_Alpha(Code) then
elsif R.Is_Rune(Code, R.V.Number_Sign) then -- #
Set_Lexer_State (C, LX_HASHED, Code);
elsif R.Is_Rune(Code, R.V.Dollar_Sign) then -- $
Set_Lexer_State (C, LX_DOLLARED, Code);
elsif R.Is_Rune(Code, R.V.Left_Curly_Bracket) then -- {
Start_Token (C, Code);
End_Token (C, TK_LBRACE);
elsif R.Is_Rune(Code, R.V.Right_Curly_Bracket) then -- }
Start_Token (C, Code);
End_Token (C, TK_RBRACE);
elsif R.Is_Rune(Code, R.V.Left_Square_Bracket) then -- [
Start_Token (C, Code);
End_Token (C, TK_LBRACK);
elsif R.Is_Rune(Code, R.V.Right_Square_Bracket) then -- ]
Start_Token (C, Code);
End_Token (C, TK_RBRACK);
elsif R.Is_Rune(Code, R.V.Left_Parenthesis) then -- (
Start_Token (C, Code);
End_Token (C, TK_LPAREN);
elsif R.Is_Rune(Code, R.V.Right_Parenthesis) then -- )
Start_Token (C, Code);
End_Token (C, TK_RPAREN);
elsif R.Is_Rune(Code, R.V.Semicolon) then -- ;
Start_Token (C, Code);
End_Token (C, TK_SEMICOLON);
elsif Is_Ident_Starter(Code) then
Set_Lexer_State (C, LX_IDENT, Code);
elsif R.Is_Digit(Code) then
Set_Lexer_State (C, LX_NUMBER, Code);
@ -294,13 +336,8 @@ package body H3.Compilers is
Set_Lexer_State (C, LX_OP_LESS, Code);
elsif R.Is_Rune(Code, R.V.Right_Arrow) then -- >
Set_Lexer_State (C, LX_OP_GREATER, Code);
elsif R.Is_Rune(Code, R.V.Number_Sign) then -- #
Set_Lexer_State (C, LX_DIRECTIVE, Code);
elsif R.Is_Rune(Code, R.V.Quotation) then -- "
Set_Lexer_State (C, LX_CSTR);
elsif R.Is_Rune(Code, R.V.Semicolon) then
Start_Token (C, Code);
End_Token (C, TK_SEMICOLON);
else
raise Syntax_Error;
end if;
@ -314,7 +351,13 @@ package body H3.Compilers is
end if;
when LX_COMMENT =>
null;
if R.Is_Eof(Code) then
Set_Lexer_State (C, LX_START);
goto Start_Over;
elsif R.Is_Rune(Code, R.V.LF) then -- TODO: support a different EOL scheme
Start_Token (C, LB_EOL);
End_Token (C, TK_EOL);
end if;
when LX_CSTR =>
-- TODO: escaping...
@ -324,9 +367,36 @@ package body H3.Compilers is
Feed_Token (C, Code);
end if;
when LX_IDENT =>
when LX_DOLLARED =>
if R.Is_Rune(Code, R.V.Left_Curly_Bracket) then
End_Token (C, TK_DOLLARED_LBRACE, Code);
elsif R.Is_Rune(Code, R.V.Left_Square_Bracket) then
End_Token (C, TK_DOLLARED_LBRACK, Code);
elsif R.Is_Rune(Code, R.V.Left_Parenthesis) then
End_Token (C, TK_DOLLARED_LPAREN, Code);
else
raise Syntax_Error with "invalid dollared token";
end if;
when LX_HASHED =>
if R.Is_Alnum(Code) or else R.Is_Rune(Code, R.V.Underline) then
Feed_Token (C, Code);
Switch_Lexer_State (C, LX_DIRECTIVE);
elsif R.Is_Rune(Code, R.V.Number_Sign) then -- ##
Set_Lexer_State (C, LX_COMMENT);
elsif R.Is_Rune(Code, R.V.Left_Curly_Bracket) then
End_Token (C, TK_HASHED_LBRACE, Code);
elsif R.Is_Rune(Code, R.V.Left_Square_Bracket) then
End_Token (C, TK_HASHED_LBRACK, Code);
elsif R.Is_Rune(Code, R.V.Left_Parenthesis) then
End_Token (C, TK_HASHED_LPAREN, Code);
else
raise Syntax_Error with "invalid hashed token";
end if;
when LX_IDENT =>
if Is_Ident_Char(Code) then
Feed_Token (C, Code);
else
End_Token (C, TK_IDENT);
goto Start_Over;
@ -392,14 +462,28 @@ package body H3.Compilers is
end Feed_Char_Code;
procedure Feed_Inc (C: in out Compiler) is
-- Feed the contents of a included stream.
Entry_Top: constant System_Index := C.Inc.Top;
Use_Immediate: constant Boolean := True;
begin
loop
while not Ada.Text_IO.End_Of_File(C.Inc.Streams(C.Inc.Top).Handle) loop
declare
Ch: Standard.Character;
begin
Ada.Text_IO.Get (C.Inc.Streams(C.Inc.Top).Handle, Ch);
-- Get() skips line terminators. End_Of_Line() checks if it reaches EOL
-- but can't handle multiple consecutive EOLs. Get_Immediate() doesn't
-- skip EOLs. As detecting every EOL in the multiple consecutive sequence
-- is not required, End_Of_Line()+Get() is good too.
if Use_Immediate then
Ada.Text_IO.Get_Immediate (C.Inc.Streams(C.Inc.Top).Handle, Ch);
else
if Ada.Text_IO.End_Of_Line(C.Inc.Streams(C.Inc.Top).Handle) then
Feed_Char_Code (C, R.P.LF);
end if;
Ada.Text_IO.Get (C.Inc.Streams(C.Inc.Top).Handle, Ch);
end if;
Feed_Char_Code (C, Standard.Character'Pos(Ch));
end;
-- After each feed, C.Inc.Top may get incremented if an inclusion
@ -424,7 +508,6 @@ package body H3.Compilers is
begin
for i in Data'Range loop
Feed_Char_Code (C, R.To_Code(Data(i)));
if C.Inc.Top > 0 then
Feed_Inc (C);
end if;

View File

@ -27,6 +27,8 @@ private
LX_COMMENT,
LX_CSTR,
LX_DIRECTIVE,
LX_DOLLARED,
LX_HASHED,
LX_IDENT,
LX_NUMBER,
LX_OP_DIV,
@ -48,12 +50,21 @@ private
TK_DIRECTIVE,
TK_DIV,
TK_DIVDIV,
TK_DOLLARED_LBRACE,
TK_DOLLARED_LBRACK,
TK_DOLLARED_LPAREN,
TK_EOF,
TK_EOL,
TK_HASHED_LBRACE,
TK_HASHED_LBRACK,
TK_HASHED_LPAREN,
TK_IDENT,
TK_GE,
TK_GT,
TK_LBRACE,
TK_LBRACK,
TK_LE,
TK_LPAREN,
TK_LT,
TK_MINUS,
TK_MINUSMINUS,
@ -61,6 +72,9 @@ private
TK_MULMUL,
TK_PLUS,
TK_PLUSPLUS,
TK_RBRACE,
TK_RBRACK,
TK_RPAREN,
TK_SEMICOLON
);
type Token is record

115
lib2/sample-lang.txt Normal file
View File

@ -0,0 +1,115 @@
ls -laF
print @get-jobs
print $(get-jobs)
(defun a (a b c)
ddddd
)
fun a (a b c) => e f
e = 20
f = 30
end
class t
fun a(a b c) => e f
while a < b
if a < b
else
end
end
for i = 1 to 20
end
end
end
#####################################################
$() <--- process execution expansion
{...} <--- range?
[ 1 2 3 ] <--- array
#() <-- array???
#[] <-- hash table??
#{} <-- ???
#<> <--?
$() <---
$[] <---
${} <---
$<> <---
if cmd
end
while cmd
end
fun fib a
let a = 20 <-- use it as if it's an declaration + init??
"let" a = 20 <--- call the command let
@a = 20 <-- lvalue
$a <-- rvalue
return $a
end
"fun" fib a <--- call the command 'fun', fun it not special??
function name as lvalue? function name as rvalue??
fib 10 <--- call the function.
let x = fib <--- what is this syntax? assigning the function fib to x? it's not call?
let x = $[fib]
let x = $[fib < /dev/null >/dev/null]
$(fib a) <-- capture
@a = $[fib 20] <-- capture return value
@a = $(fib 20) <-- capture stdout??
@a = $[fib $[ls -laF]]
@a = $[fib $(ls -laF)]
complex expression inside $[] and $()??
$(
printf "abc";
if ...
...
else
...
end
)
class X ### class X Y <--- Y is a parent class?
names := #[] <- array?
tools := #{} <- hash table?
fun __construct name
names.add name
let k := 20
k := $(20 + 30)
return k
@names<20> = "jelly"
@tools<"donkey"> = names;
@tools.donkey = names?
@k = $tools.donkey >>>> "${tools.donkey}" ${tools.donkey} "${tools}.donkey"
end
fun say_hi msg
print msg
ls -laF << execute external command if the global variable PATH is not null
<< external command is disabled if PATH is null
/bin/ls -alF << if the command begins with /, it still allows execution if this feature is not disabled
return 20
end
end