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elna/source/Lexer.elna

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(* This Source Code Form is subject to the terms of the Mozilla Public License,
v. 2.0. If a copy of the MPL was not distributed with this file, You can
obtain one at https://mozilla.org/MPL/2.0/. *)
module;
import cstdio, cstring, common;
const
CHUNK_SIZE := 85536;
type
(*
* Classification table assigns each possible character to a group (class). All
* characters of the same group a handled equivalently.
*
* Classification:
*)
TransitionClass = (
invalid,
digit,
alpha,
space,
colon,
equals,
left_paren,
right_paren,
asterisk,
underscore,
single,
hex,
zero,
x,
eof,
dot,
minus,
single_quote,
double_quote,
greater,
less,
other
);
TransitionState = (
start,
colon,
identifier,
decimal,
greater,
minus,
left_paren,
less,
dot,
comment,
closing_comment,
character,
string,
leading_zero,
decimal_suffix,
finish
);
LexerToken = record
kind: LexerKind;
value: union
booleanKind: Bool;
identifierKind: Identifier;
integerKind: Int;
stringKind: String
end;
start_location: TextLocation;
end_location: TextLocation
end;
TransitionAction = proc(^Lexer, ^LexerToken);
Transition = record
action: TransitionAction;
next_state: TransitionState
end;
TransitionClasses = [22]Transition;
BufferPosition* = record
iterator: ^Char;
location: TextLocation
end;
Lexer* = record
input: ^FILE;
buffer: ^Char;
size: Word;
length: Word;
start: BufferPosition;
current: BufferPosition
end;
LexerKind* = (
eof,
identifier,
_if,
_then,
_else,
_elsif,
_while,
_do,
_proc,
_begin,
_end,
_xor,
_const,
_var,
_case,
_of,
_type,
_record,
_union,
pipe,
to,
boolean,
null,
and,
_or,
tilde,
_return,
_defer,
range,
left_paren,
right_paren,
lefts_quare,
right_square,
greater_equal,
less_equal,
greater_than,
less_than,
not_equal,
equal,
semicolon,
dot,
comma,
plus,
minus,
asterisk,
division,
remainder,
assignment,
colon,
hat,
at,
comment,
integer,
word,
character,
string,
from,
pointer,
array,
arrow,
_program,
_module,
_import
);
var
classification: [128]TransitionClass;
transitions: [16]TransitionClasses;
proc initialize_classification();
var
i: Word;
begin
classification[1] := TransitionClass.eof; (* NUL *)
classification[2] := TransitionClass.invalid; (* SOH *)
classification[3] := TransitionClass.invalid; (* STX *)
classification[4] := TransitionClass.invalid; (* ETX *)
classification[5] := TransitionClass.invalid; (* EOT *)
classification[6] := TransitionClass.invalid; (* EMQ *)
classification[7] := TransitionClass.invalid; (* ACK *)
classification[8] := TransitionClass.invalid; (* BEL *)
classification[9] := TransitionClass.invalid; (* BS *)
classification[10] := TransitionClass.space; (* HT *)
classification[11] := TransitionClass.space; (* LF *)
classification[12] := TransitionClass.invalid; (* VT *)
classification[13] := TransitionClass.invalid; (* FF *)
classification[14] := TransitionClass.space; (* CR *)
classification[15] := TransitionClass.invalid; (* SO *)
classification[16] := TransitionClass.invalid; (* SI *)
classification[17] := TransitionClass.invalid; (* DLE *)
classification[18] := TransitionClass.invalid; (* DC1 *)
classification[19] := TransitionClass.invalid; (* DC2 *)
classification[20] := TransitionClass.invalid; (* DC3 *)
classification[21] := TransitionClass.invalid; (* DC4 *)
classification[22] := TransitionClass.invalid; (* NAK *)
classification[23] := TransitionClass.invalid; (* SYN *)
classification[24] := TransitionClass.invalid; (* ETB *)
classification[25] := TransitionClass.invalid; (* CAN *)
classification[26] := TransitionClass.invalid; (* EM *)
classification[27] := TransitionClass.invalid; (* SUB *)
classification[28] := TransitionClass.invalid; (* ESC *)
classification[29] := TransitionClass.invalid; (* FS *)
classification[30] := TransitionClass.invalid; (* GS *)
classification[31] := TransitionClass.invalid; (* RS *)
classification[32] := TransitionClass.invalid; (* US *)
classification[33] := TransitionClass.space; (* Space *)
classification[34] := TransitionClass.single; (* ! *)
classification[35] := TransitionClass.double_quote; (* " *)
classification[36] := TransitionClass.other; (* # *)
classification[37] := TransitionClass.other; (* $ *)
classification[38] := TransitionClass.single; (* % *)
classification[39] := TransitionClass.single; (* & *)
classification[40] := TransitionClass.single_quote; (* ' *)
classification[41] := TransitionClass.left_paren; (* ( *)
classification[42] := TransitionClass.right_paren; (* ) *)
classification[43] := TransitionClass.asterisk; (* * *)
classification[44] := TransitionClass.single; (* + *)
classification[45] := TransitionClass.single; (* , *)
classification[46] := TransitionClass.minus; (* - *)
classification[47] := TransitionClass.dot; (* . *)
classification[48] := TransitionClass.single; (* / *)
classification[49] := TransitionClass.zero; (* 0 *)
classification[50] := TransitionClass.digit; (* 1 *)
classification[51] := TransitionClass.digit; (* 2 *)
classification[52] := TransitionClass.digit; (* 3 *)
classification[53] := TransitionClass.digit; (* 4 *)
classification[54] := TransitionClass.digit; (* 5 *)
classification[55] := TransitionClass.digit; (* 6 *)
classification[56] := TransitionClass.digit; (* 7 *)
classification[57] := TransitionClass.digit; (* 8 *)
classification[58] := TransitionClass.digit; (* 9 *)
classification[59] := TransitionClass.colon; (* : *)
classification[60] := TransitionClass.single; (* ; *)
classification[61] := TransitionClass.less; (* < *)
classification[62] := TransitionClass.equals; (* = *)
classification[63] := TransitionClass.greater; (* > *)
classification[64] := TransitionClass.other; (* ? *)
classification[65] := TransitionClass.single; (* @ *)
classification[66] := TransitionClass.alpha; (* A *)
classification[67] := TransitionClass.alpha; (* B *)
classification[68] := TransitionClass.alpha; (* C *)
classification[69] := TransitionClass.alpha; (* D *)
classification[70] := TransitionClass.alpha; (* E *)
classification[71] := TransitionClass.alpha; (* F *)
classification[72] := TransitionClass.alpha; (* G *)
classification[73] := TransitionClass.alpha; (* H *)
classification[74] := TransitionClass.alpha; (* I *)
classification[75] := TransitionClass.alpha; (* J *)
classification[76] := TransitionClass.alpha; (* K *)
classification[77] := TransitionClass.alpha; (* L *)
classification[78] := TransitionClass.alpha; (* M *)
classification[79] := TransitionClass.alpha; (* N *)
classification[80] := TransitionClass.alpha; (* O *)
classification[81] := TransitionClass.alpha; (* P *)
classification[82] := TransitionClass.alpha; (* Q *)
classification[83] := TransitionClass.alpha; (* R *)
classification[84] := TransitionClass.alpha; (* S *)
classification[85] := TransitionClass.alpha; (* T *)
classification[86] := TransitionClass.alpha; (* U *)
classification[87] := TransitionClass.alpha; (* V *)
classification[88] := TransitionClass.alpha; (* W *)
classification[89] := TransitionClass.alpha; (* X *)
classification[90] := TransitionClass.alpha; (* Y *)
classification[91] := TransitionClass.alpha; (* Z *)
classification[92] := TransitionClass.single; (* [ *)
classification[93] := TransitionClass.other; (* \ *)
classification[94] := TransitionClass.single; (* ] *)
classification[95] := TransitionClass.single; (* ^ *)
classification[96] := TransitionClass.underscore; (* _ *)
classification[97] := TransitionClass.other; (* ` *)
classification[98] := TransitionClass.hex; (* a *)
classification[99] := TransitionClass.hex; (* b *)
classification[100] := TransitionClass.hex; (* c *)
classification[101] := TransitionClass.hex; (* d *)
classification[102] := TransitionClass.hex; (* e *)
classification[103] := TransitionClass.hex; (* f *)
classification[104] := TransitionClass.alpha; (* g *)
classification[105] := TransitionClass.alpha; (* h *)
classification[106] := TransitionClass.alpha; (* i *)
classification[107] := TransitionClass.alpha; (* j *)
classification[108] := TransitionClass.alpha; (* k *)
classification[109] := TransitionClass.alpha; (* l *)
classification[110] := TransitionClass.alpha; (* m *)
classification[111] := TransitionClass.alpha; (* n *)
classification[112] := TransitionClass.alpha; (* o *)
classification[113] := TransitionClass.alpha; (* p *)
classification[114] := TransitionClass.alpha; (* q *)
classification[115] := TransitionClass.alpha; (* r *)
classification[116] := TransitionClass.alpha; (* s *)
classification[117] := TransitionClass.alpha; (* t *)
classification[118] := TransitionClass.alpha; (* u *)
classification[119] := TransitionClass.alpha; (* v *)
classification[120] := TransitionClass.alpha; (* w *)
classification[121] := TransitionClass.x; (* x *)
classification[122] := TransitionClass.alpha; (* y *)
classification[123] := TransitionClass.alpha; (* z *)
classification[124] := TransitionClass.other; (* { *)
classification[125] := TransitionClass.single; (* | *)
classification[126] := TransitionClass.other; (* } *)
classification[127] := TransitionClass.single; (* ~ *)
classification[128] := TransitionClass.invalid; (* DEL *)
i := 129u;
while i <= 256u do
classification[i] := TransitionClass.other;
i := i + 1u
end
end;
proc compare_keyword(keyword: String, token_start: BufferPosition, token_end: ^Char) -> Bool;
var
result: Bool;
index: Word;
keyword_length: Word;
continue: Bool;
begin
index := 0u;
result := true;
keyword_length := Length(keyword);
continue := (index < keyword_length) & (token_start.iterator <> token_end);
while continue & result do
result := (keyword[index] = token_start.iterator^) or (Lower(keyword[index]) = token_start.iterator^);
token_start.iterator := token_start.iterator + 1;
index := index + 1u;
continue := (index < keyword_length) & (token_start.iterator <> token_end)
end;
result := result & (index = Length(keyword));
return result & (token_start.iterator = token_end)
end;
(* Reached the end of file. *)
proc transition_action_eof(lexer: ^Lexer, token: ^LexerToken);
begin
token^.kind := LexerKind.eof
end;
proc increment(position: ^BufferPosition);
begin
position^.iterator := position^.iterator + 1
end;
(* Add the character to the token currently read and advance to the next character. *)
proc transition_action_accumulate(lexer: ^Lexer, token: ^LexerToken);
begin
increment(@lexer^.current)
end;
(* The current character is not a part of the token. Finish the token already
* read. Don't advance to the next character. *)
proc transition_action_finalize(lexer: ^Lexer, token: ^LexerToken);
begin
if lexer^.start.iterator^ = ':' then
token^.kind := LexerKind.colon
end;
if lexer^.start.iterator^ = '>' then
token^.kind := LexerKind.greater_than
end;
if lexer^.start.iterator^ = '<' then
token^.kind := LexerKind.less_than
end;
if lexer^.start.iterator^ = '(' then
token^.kind := LexerKind.left_paren
end;
if lexer^.start.iterator^ = '-' then
token^.kind := LexerKind.minus
end;
if lexer^.start.iterator^ = '.' then
token^.kind := LexerKind.dot
end
end;
(* An action for tokens containing multiple characters. *)
proc transition_action_composite(lexer: ^Lexer, token: ^LexerToken);
begin
if lexer^.start.iterator^ = '<' then
if lexer^.current.iterator^ = '>' then
token^.kind := LexerKind.not_equal
end;
if lexer^.current.iterator^ = '=' then
token^.kind := LexerKind.less_equal
end
end;
if (lexer^.start.iterator^ = '>') & (lexer^.current.iterator^ = '=') then
token^.kind := LexerKind.greater_equal
end;
if (lexer^.start.iterator^ = '.') & (lexer^.current.iterator^ = '.') then
token^.kind := LexerKind.range
end;
if (lexer^.start.iterator^ = ':') & (lexer^.current.iterator^ = '=') then
token^.kind := LexerKind.assignment
end;
if (lexer^.start.iterator^ = '-') & (lexer^.current.iterator^ = '>') then
token^.kind := LexerKind.arrow
end;
increment(@lexer^.current)
end;
(* Skip a space. *)
proc transition_action_skip(lexer: ^Lexer, token: ^LexerToken);
begin
increment(@lexer^.start);
if lexer^.start.iterator^ = '\n' then
lexer^.start.location.line := lexer^.start.location.line + 1u;
lexer^.start.location.column := 1u
end;
lexer^.current := lexer^.start
end;
(* Delimited string action. *)
proc transition_action_delimited(lexer: ^Lexer, token: ^LexerToken);
var
text_length: Word;
begin
if lexer^.start.iterator^ = '(' then
token^.kind := LexerKind.comment
end;
if lexer^.start.iterator^ = '"' then
text_length := cast(lexer^.current.iterator - lexer^.start.iterator + 1: Word);
token^.stringKind := String(malloc(text_length), text_length);
memcpy(@token^.stringKind.ptr, lexer^.start.iterator, text_length);
token^.kind := LexerKind.character
end;
if lexer^.start.iterator^ = "'" then
text_length := cast(lexer^.current.iterator - lexer^.start.iterator + 1: Word);
token^.stringKind := String(malloc(text_length), text_length);
memcpy(@token^.stringKind.ptr, lexer^.start.iterator, text_length);
token^.kind := LexerKind.string
end;
increment(@lexer^.current)
end;
(* Finalize keyword or identifier. *)
proc transition_action_key_id(lexer: ^Lexer, token: ^LexerToken);
begin
token^.kind := LexerKind.identifier;
token^.identifierKind[1] := cast(lexer^.current.iterator - lexer^.start.iterator: Char);
memcpy(@token^.identifierKind[2], lexer^.start.iterator, ORD(token^.identifierKind[1]));
if compare_keyword("program", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._program
end;
if compare_keyword("import", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._import
end;
if compare_keyword("const", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._const
end;
if compare_keyword("var", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._var
end;
if compare_keyword("if", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._if
end;
if compare_keyword("then", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._then
end;
if compare_keyword("elsif", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._elsif
end;
if compare_keyword("else", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._else
end;
if compare_keyword("while", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._while
end;
if compare_keyword("do", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._do
end;
if compare_keyword("proc", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._proc
end;
if compare_keyword("begin", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._begin
end;
if compare_keyword("end", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._end
end;
if compare_keyword("type", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._type
end;
if compare_keyword("record", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._record
end;
if compare_keyword("union", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._union
end;
if compare_keyword("NIL", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.null
end;
if compare_keyword("or", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._or
end;
if compare_keyword("return", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._return
end;
if compare_keyword("defer", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._defer
end;
if compare_keyword("TO", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.to
end;
if compare_keyword("CASE", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._case
end;
if compare_keyword("OF", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._of
end;
if compare_keyword("FROM", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.from
end;
if compare_keyword("module", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._module
end;
if compare_keyword("xor", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind._xor
end;
if compare_keyword("POINTER", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.pointer
end;
if compare_keyword("ARRAY", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.array
end;
if compare_keyword("TRUE", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.boolean;
token^.booleanKind := true
end;
if compare_keyword("FALSE", lexer^.start, lexer^.current.iterator) then
token^.kind := LexerKind.boolean;
token^.booleanKind := false
end
end;
(* Action for tokens containing only one character. The character cannot be
* followed by other characters forming a composite token. *)
proc transition_action_single(lexer: ^Lexer, token: ^LexerToken);
begin
if lexer^.current.iterator^ = '&' then
token^.kind := LexerKind.and
end;
if lexer^.current.iterator^ = ';' then
token^.kind := LexerKind.semicolon
end;
if lexer^.current.iterator^ = ',' then
token^.kind := LexerKind.comma
end;
if lexer^.current.iterator^ = '~' then
token^.kind := LexerKind.tilde
end;
if lexer^.current.iterator^ = ')' then
token^.kind := LexerKind.right_paren
end;
if lexer^.current.iterator^ = '[' then
token^.kind := LexerKind.left_square
end;
if lexer^.current.iterator^ = ']' then
token^.kind := LexerKind.right_square
end;
if lexer^.current.iterator^ = '^' then
token^.kind := LexerKind.hat
end;
if lexer^.current.iterator^ = '=' then
token^.kind := LexerKind.equal
end;
if lexer^.current.iterator^ = '+' then
token^.kind := LexerKind.plus
end;
if lexer^.current.iterator^ = '*' then
token^.kind := LexerKind.asterisk
end;
if lexer^.current.iterator^ = '/' then
token^.kind := LexerKind.division
end;
if lexer^.current.iterator^ = '%' then
token^.kind := LexerKind.remainder
end;
if lexer^.current.iterator^ = '@' then
token^.kind := LexerKind.at
end;
if lexer^.current.iterator^ = '|' then
token^.kind := LexerKind.pipe
end;
increment(@lexer^.current.iterator)
end;
(* Handle an integer literal. *)
proc transition_action_integer(lexer: ^Lexer, token: ^LexerToken);
var
buffer: String;
integer_length: Int;
found: Bool;
begin
token^.kind := LexerKind.integer;
integer_length := lexer^.current.iterator - lexer^.start.iterator;
memset(@token^.identifierKind, 0, #size(Identifier));
memcpy(@token^.identifierKind[1], lexer^.start.iterator, integer_length);
buffer := InitStringCharStar(@token^.identifierKind[1]);
token^.integerKind := StringToInteger(buffer, 10, found);
buffer := KillString(buffer)
end;
proc set_default_transition(current_state: TransitionState, default_action: TransitionAction, next_state: TransitionState) -> Int;
var
default_transition: Transition;
state_index: Int;
begin
default_transition.action := default_action;
default_transition.next_state := next_state;
state_index := cast(current_state: Int) + 1;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.digit: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.space: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.colon: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.equals: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.left_paren: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.right_paren: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.single: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.hex: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.zero: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.x: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.eof: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.dot: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.minus: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.single_quote: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.double_quote: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.greater: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.less: Int) + 1] := default_transition;
transitions[state_index][cast(TransitionClass.other: Int) + 1] := default_transition;
return state_index
end;
(*
* The transition table describes transitions from one state to another, given
* a symbol (character class).
*
* The table has m rows and n columns, where m is the amount of states and n is
* the amount of classes. So given the current state and a classified character
* the table can be used to look up the next state.
*
* Each cell is a word long.
* - The least significant byte of the word is a row number (beginning with 0).
* It specifies the target state. "ff" means that this is an end state and no
* transition is possible.
* - The next byte is the action that should be performed when transitioning.
* For the meaning of actions see labels in the lex_next function, which
* handles each action.
*)
proc initialize_transitions();
var
state_index: Int;
begin
(* Start state. *)
state_index := cast(TransitionState.start: Int) + 1;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].next_state := TransitionState.decimal;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.space: Int) + 1].action := transition_action_skip;
transitions[state_index][cast(TransitionClass.space: Int) + 1].next_state := TransitionState.start;
transitions[state_index][cast(TransitionClass.colon: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.colon: Int) + 1].next_state := TransitionState.colon;
transitions[state_index][cast(TransitionClass.equals: Int) + 1].action := transition_action_single;
transitions[state_index][cast(TransitionClass.equals: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.left_paren: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.left_paren: Int) + 1].next_state := TransitionState.left_paren;
transitions[state_index][cast(TransitionClass.right_paren: Int) + 1].action := transition_action_single;
transitions[state_index][cast(TransitionClass.right_paren: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].action := transition_action_single;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.single: Int) + 1].action := transition_action_single;
transitions[state_index][cast(TransitionClass.single: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].next_state := TransitionState.leading_zero;
transitions[state_index][cast(TransitionClass.x: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.x: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].action := transition_action_eof;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.dot: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.dot: Int) + 1].next_state := TransitionState.dot;
transitions[state_index][cast(TransitionClass.minus: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.minus: Int) + 1].next_state := TransitionState.minus;
transitions[state_index][cast(TransitionClass.single_quote: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.single_quote: Int) + 1].next_state := TransitionState.character;
transitions[state_index][cast(TransitionClass.double_quote: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.double_quote: Int) + 1].next_state := TransitionState.string;
transitions[state_index][cast(TransitionClass.greater: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.greater: Int) + 1].next_state := TransitionState.greater;
transitions[state_index][cast(TransitionClass.less: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.less: Int) + 1].next_state := TransitionState.less;
transitions[state_index][cast(TransitionClass.other: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.other: Int) + 1].next_state := TransitionState.finish;
(* Colon state. *)
state_index := set_default_transition(TransitionState.colon, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.equals: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.equals: Int) + 1].next_state := TransitionState.finish;
(* Identifier state. *)
state_index := set_default_transition(TransitionState.identifier, transition_action_key_id, TransitionState.finish);
transitions[state_index][cast(TransitionClass.digit: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].next_state := TransitionState.identifier;
transitions[state_index][cast(TransitionClass.x: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.x: Int) + 1].next_state := TransitionState.identifier;
(* Decimal state. *)
state_index := set_default_transition(TransitionState.decimal, transition_action_integer, TransitionState.finish);
transitions[state_index][cast(TransitionClass.digit: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].next_state := TransitionState.decimal;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].next_state := TransitionState.decimal_suffix;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].next_state := TransitionState.decimal_suffix;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].next_state := TransitionState.decimal;
transitions[state_index][cast(TransitionClass.x: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.x: Int) + 1].next_state := TransitionState.decimal_suffix;
(* Greater state. *)
state_index := set_default_transition(TransitionState.greater, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.equals: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.equals: Int) + 1].next_state := TransitionState.finish;
(* Minus state. *)
state_index := set_default_transition(TransitionState.minus, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.greater: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.greater: Int) + 1].next_state := TransitionState.finish;
(* Left paren state. *)
state_index := set_default_transition(TransitionState.left_paren, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].next_state := TransitionState.comment;
(* Less state. *)
state_index := set_default_transition(TransitionState.less, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.equals: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.equals: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.greater: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.greater: Int) + 1].next_state := TransitionState.finish;
(* Hexadecimal after 0x. *)
state_index := set_default_transition(TransitionState.dot, transition_action_finalize, TransitionState.finish);
transitions[state_index][cast(TransitionClass.dot: Int) + 1].action := transition_action_composite;
transitions[state_index][cast(TransitionClass.dot: Int) + 1].next_state := TransitionState.finish;
(* Comment. *)
state_index := set_default_transition(TransitionState.comment, transition_action_accumulate, TransitionState.comment);
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].next_state := TransitionState.closing_comment;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].next_state := TransitionState.finish;
(* Closing comment. *)
state_index := set_default_transition(TransitionState.closing_comment, transition_action_accumulate, TransitionState.comment);
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.right_paren: Int) + 1].action := transition_action_delimited;
transitions[state_index][cast(TransitionClass.right_paren: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].action := transition_action_accumulate;
transitions[state_index][cast(TransitionClass.asterisk: Int) + 1].next_state := TransitionState.closing_comment;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].next_state := TransitionState.finish;
(* Character. *)
state_index := set_default_transition(TransitionState.character, transition_action_accumulate, TransitionState.character);
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.single_quote: Int) + 1].action := transition_action_delimited;
transitions[state_index][cast(TransitionClass.single_quote: Int) + 1].next_state := TransitionState.finish;
(* String. *)
state_index := set_default_transition(TransitionState.string, transition_action_accumulate, TransitionState.string);
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.invalid: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.eof: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.double_quote: Int) + 1].action := transition_action_delimited;
transitions[state_index][cast(TransitionClass.double_quote: Int) + 1].next_state := TransitionState.finish;
(* Leading zero. *)
state_index := set_default_transition(TransitionState.leading_zero, transition_action_integer, TransitionState.finish);
transitions[state_index][cast(TransitionClass.digit: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.underscore: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.x: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.x: Int) + 1].next_state := TransitionState.finish;
(* Digit with a character suffix. *)
state_index := set_default_transition(TransitionState.decimal_suffix, transition_action_integer, TransitionState.finish);
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.alpha: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.digit: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.hex: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.zero: Int) + 1].next_state := TransitionState.finish;
transitions[state_index][cast(TransitionClass.x: Int) + 1].action := nil;
transitions[state_index][cast(TransitionClass.x: Int) + 1].next_state := TransitionState.finish
end;
proc lexer_make*(lexer: ^Lexer, input: ^FILE);
begin
lexer^.input := input;
lexer^.length := 0;
lexer^.buffer := malloc(CHUNK_SIZE);
memset(lexer^.buffer, 0, CHUNK_SIZE);
lexer^.size := CHUNK_SIZE
end;
(* Returns the last read token. *)
proc lexer_current*(lexer: ^Lexer) -> LexerToken;
var
current_class: TransitionClass;
current_state: TransitionState;
current_transition: Transition;
result: LexerToken;
index1: Word;
index2: Word;
begin
lexer^.current := lexer^.start;
current_state := TransitionState.start;
while current_state <> TransitionState.finish do
index1 := cast(lexer^.current.iterator^: Word) + 1u;
current_class := classification[index1];
index1 := cast(current_state: Word) + 1u;
index2 := cast(current_class: Word) + 1u;
current_transition := transitions[index1][index2];
if current_transition.action <> nil then
current_transition.action(lexer, @result)
end;
current_state := current_transition.next_state
end;
result.start_location := lexer^.start.location;
result.end_location := lexer^.current.location;
return result
end;
(* Read and return the next token. *)
proc lexer_lex*(lexer: ^Lexer) -> LexerToken;
var
result: LexerToken;
begin
if lexer^.length = 0 then
lexer^.length := ReadNBytes(lexer^.input, CHUNK_SIZE, lexer^.buffer);
lexer^.current.location.column := 1;
lexer^.current.location.line := 1;
lexer^.current.iterator := lexer^.buffer
end;
lexer^.start := lexer^.current;
result := lexer_current(lexer);
return result
end;
proc lexer_destroy*(lexer: ^Lexer);
begin
free(lexer^.buffer)
end;
proc lexer_initialize();
begin
initialize_classification();
initialize_transitions()
end;
end.