public void TerminalLexemShouldWhileAcceptedContinuesToMatch()
{
var terminalLexeme = new TerminalLexeme(
new CharacterTerminal('c'),
new TokenType("c"),
0);
Assert.IsFalse(terminalLexeme.IsAccepted());
Assert.IsTrue(terminalLexeme.Scan('c'));
Assert.IsTrue(terminalLexeme.IsAccepted());
Assert.IsFalse(terminalLexeme.Scan('c'));
}
public void TerminalLexemeResetShouldClearPreExistingValues()
{
var terminalLexeme = new TerminalLexeme(
new CharacterTerminal('c'),
new TokenType("c"),
0);
Assert.IsTrue(terminalLexeme.Scan('c'));
terminalLexeme.Reset(
new TerminalLexerRule(new CharacterTerminal('a'), new TokenType("a")),
10);
Assert.AreEqual(10, terminalLexeme.Position);
}
public void TerminalLexemShouldWhileAcceptedContinuesToMatch()
{
var input = "c";
var segment = input.AsCapture();
var terminalLexeme = new TerminalLexeme(
new CharacterTerminal('c'),
new TokenType("c"),
segment,
0);
Assert.IsFalse(terminalLexeme.IsAccepted());
Assert.IsTrue(terminalLexeme.Scan());
Assert.IsTrue(terminalLexeme.IsAccepted());
Assert.IsFalse(terminalLexeme.Scan());
}
public override bool Scan()
{
// get expected lexems
// PERF: Avoid Linq where, let and select expressions due to lambda allocation
var expectedLexemes = SharedPools.Default <List <TerminalLexeme> >().AllocateAndClear();
var expectedLexerRules = _parseEngine.GetExpectedLexerRules();
foreach (var rule in expectedLexerRules)
{
if (rule.LexerRuleType == TerminalLexerRule.TerminalLexerRuleType)
{
expectedLexemes.Add(
new TerminalLexeme(
rule as ITerminalLexerRule,
Capture,
_parseEngine.Location));
}
}
// filter on first rule to pass (since all rules are one character per lexeme)
// PERF: Avoid Linq FirstOrDefault due to lambda allocation
TerminalLexeme firstPassingRule = null;
foreach (var lexeme in expectedLexemes)
{
if (lexeme.Scan())
{
firstPassingRule = lexeme;
break;
}
}
SharedPools.Default <List <TerminalLexeme> >()
.ClearAndFree(expectedLexemes);
if (firstPassingRule is null)
{
return(false);
}
var result = _parseEngine.Pulse(firstPassingRule);
if (!result)
{
return(false);
}
return(Capture.Grow());
}
public void TerminalLexemeResetShouldClearPreExistingValues()
{
var input = "c";
var segment = input.AsCapture();
var terminalLexeme = new TerminalLexeme(
new CharacterTerminal('c'),
new TokenType("c"),
segment,
0);
Assert.IsTrue(terminalLexeme.Scan());
terminalLexeme.Reset(
new TerminalLexerRule(new CharacterTerminal('a'), new TokenType("a")),
0);
Assert.AreEqual(0, terminalLexeme.Position);
}
public void TerminalLexemeShouldInitializeCatpureToEmptyString()
{
var terminalLexeme = new TerminalLexeme(new CharacterTerminal('c'), new TokenType("c"), 0);
Assert.AreEqual(string.Empty, terminalLexeme.Value);
}
