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194 | -- -----------------------------------------------------------------------------
-- bbt, the black box tester (https://github.com/LionelDraghi/bbt)
-- Author : Lionel Draghi
-- SPDX-License-Identifier: APSL-2.0
-- SPDX-FileCopyrightText: 2024, Lionel Draghi
-- -----------------------------------------------------------------------------
with Ada.Characters.Latin_1,
Ada.Containers.Indefinite_Vectors,
Ada.Strings.Fixed,
Ada.Strings.Maps.Constants,
Ada.Strings.Maps,
Ada.Text_IO;
use Ada.Strings.Fixed;
package body BBT.Scenarios.Step_Parser.Lexer is
Cursor : Natural := 1;
Line_Finished : Boolean := False;
Backtick : constant Character := '`';
The_Delimiters : constant Ada.Strings.Maps.Character_Set
:= Ada.Strings.Maps.To_Set (" _*()" & Ada.Characters.Latin_1.HT);
package String_Arrays is new Ada.Containers.Indefinite_Vectors (Positive,
String);
Keywords : constant String_Arrays.Vector
:= ["given",
"when",
"then",
"and", -- "and" and "but" are equivalent to "Given" if they
"but", -- appear in the "Given" section, to "Then" if tey
"run", -- appear in the "Then" section, etc.
"running", -- "When I run" = "When running"
"get",
"new",
"no", -- "no" = "not" = "dont"
"not",
"dont",
"doesnt",
"doesn't",
"error",
"is",
"or",
"output",
"contain",
"contains",
"containing",
"successfully",
"file",
"dir",
"directory",
"unordered"];
-- NB : all keywords must be here in lower case!
-- -----------------------------------------------------------------------
function Is_A_Keyword (S : access constant String;
First : Positive;
Last : Natural := 0)
return Boolean
is
-- We first remove potential emphasis on keyword
-- [](https://spec.commonmark.org/0.31.2/#emphasis-and-strong-emphasis)
Emphasis : constant Ada.Strings.Maps.Character_Set
:= Ada.Strings.Maps.To_Set ("*_");
Trimmed : constant String := Trim (S.all (First .. Last),
Left => Emphasis,
Right => Emphasis);
Lower : constant String := Translate
(Source => Trimmed,
Mapping => Ada.Strings.Maps.Constants.Lower_Case_Map);
begin
-- Put_Line ("K = " & S.all (First .. Last) & ", Trimmed = " & Trimmed);
return Keywords.Contains (Lower);
end Is_A_Keyword;
-- -----------------------------------------------------------------------
procedure Initialize_Lexer is begin
Cursor := 1;
Line_Finished := False;
end Initialize_Lexer;
-- -----------------------------------------------------------------------
function Next_Token (Line : access constant String;
Tok_Type : out Token_Type)
return String is
First : Positive; -- Index of first character in token
Last : Natural := 0; -- Index of last character in token
-- Note that Cursor is >= Last
-- Cursor is the point where next call to Next_Token will start,
-- Last is the last character of the Token
-- In the case of a code span, Last will designate a character before
-- the closing backtick, and the cursor the character after.
procedure Finish_Line is
begin
Line_Finished := True;
Cursor := 1;
end Finish_Line;
begin
Find_Token (Source => Line.all (Cursor .. Line'Last),
Set => The_Delimiters,
Test => Ada.Strings.Outside,
First => First,
Last => Last);
-- Put_Line ("processing token = """ & Line.all (First .. Last) &
-- """ in " & Line.all,
-- Verbosity => IO.Debug);
Cursor := (Natural'Min (Line.all'Length, Last + 1));
-- Jump to next char unless already on the last
if Is_A_Keyword (Line, First, Last) then
-- Keyword ---------------------------------------------------------
Tok_Type := Keyword;
-- Put_Line ("Found Keyword """ & Line.all (First .. Last) &
-- """ in " & Line.all,
-- Verbosity => IO.Debug);
elsif Line (First) = Backtick then
if Line'Last > First and then Line (First + 1) /= Backtick then
-- Code span start
-- Note that we test also First + 1 because
-- "``" is not a code span start, backtick should not be
-- followed by another
Last := Index (Line.all,
[Backtick],
From => First + 1);
if Last = 0 then
IO.Put_Line ("Missing closing backtick in """ &
Line.all (Cursor .. Line'Last),
Verbosity => IO.Quiet);
Finish_Line;
else
-- Code span -------------------------------------------------
Cursor := Last + 1; -- the cursor goes over the final backtick
First := @ + 1; -- remove first backtick
Last := @ - 1; -- remove final backtick
-- Put_Line ("Found code span = """ & Line.all (First .. Last) &
-- """ in " & Line.all,
-- Verbosity => IO.Debug);
Tok_Type := Code_Span;
end if;
else
-- Jump over "``"
Tok_Type := Empty;
Cursor := First + 2;
end if;
else
-- Identifier ------------------------------------------------------
Tok_Type := Identifier;
end if;
if Cursor >= Line.all'Last then
-- It's the end of line
-- -> next line.
Finish_Line;
-- Put_Line ("EOL");
end if;
if Last = 0 then
-- nothing found
Finish_Line;
Tok_Type := Empty;
return ""; ---------------------------------------------------------
else
return (Line.all (First .. Last)); ---------------------------------
end if;
end Next_Token;
-- -----------------------------------------------------------------------
function More_Token return Boolean is
begin
return not Line_Finished;
end More_Token;
-- -----------------------------------------------------------------------
procedure Put_Keywords is
begin
for K of Keywords loop
Ada.Text_IO.Put_Line ("- " & K);
end loop;
end Put_Keywords;
end BBT.Scenarios.Step_Parser.Lexer;
|