public void TestEnv()
{
var global = new Env(null);
var main = new Env(global);
var tok = new Word("some_var", Tag.ID);
var id = new Id(tok, Sara.Type.Int, 0xff);
global.AddIdentifier(tok, id);
Assert.ReferenceEquals(id, main.Get(tok));
Assert.IsNull(global.Get(new Token(Tag.ID)));
}
public void TestWord()
{
Assert.AreEqual(Tag.AND, Word.and.TagValue);
Assert.AreEqual("&&", Word.and.Lexeme);
Assert.AreEqual(Tag.EQ, Word.eq.TagValue);
Assert.AreEqual("==", Word.eq.Lexeme);
Assert.AreEqual(Tag.FALSE, Word.False.TagValue);
Assert.AreEqual("false", Word.False.Lexeme);
Assert.AreEqual(Tag.GE, Word.ge.TagValue);
Assert.AreEqual(">=", Word.ge.Lexeme);
Assert.AreEqual(Tag.LE, Word.le.TagValue);
Assert.AreEqual("<=", Word.le.Lexeme);
Assert.AreEqual(Tag.MINUS, Word.minus.TagValue);
Assert.AreEqual("minus", Word.minus.Lexeme);
Assert.AreEqual(Tag.NE, Word.ne.TagValue);
Assert.AreEqual("!=", Word.ne.Lexeme);
Assert.AreEqual(Tag.OR, Word.or.TagValue);
Assert.AreEqual("||", Word.or.Lexeme);
Assert.AreEqual(Tag.TEMP, Word.temp.TagValue);
Assert.AreEqual("t", Word.temp.Lexeme);
Assert.AreEqual(Tag.TRUE, Word.True.TagValue);
Assert.AreEqual("true", Word.True.Lexeme);
var w = new Word("foo", Tag.ID);
Assert.AreEqual("foo", w.Lexeme);
Assert.AreEqual("foo", w.ToString());
Assert.AreEqual(Tag.ID, w.TagValue);
}
/// <summary>
/// Read and return the current token
/// </summary>
/// <returns></returns>
public Token Scan()
{
//for white spaces
for (; !this.EofReached; this.ReadChar())
{
if (_curr == ' ' || _curr == '\t')
{
continue;
}
else if (_curr == '\r')
{
this.ReadChar(); //eat \r
++Line;
}
else break;
}
if (this.EofReached) return null;
//for operators like && !=, etc
switch (_curr)
{
case '&':
return this.ReadChar('&') ? Word.and : new Token('&');
case '|':
return this.ReadChar('|') ? Word.or : new Token('|');
case '=':
return this.ReadChar('=') ? Word.eq : new Token('=');
case '!':
return this.ReadChar('=') ? Word.ne : new Token('!');
case '<':
return this.ReadChar('=') ? Word.le : new Token('<');
case '>':
return this.ReadChar('=') ? Word.ge : new Token('>');
}
//for numbers
if (char.IsDigit(_curr))
{
int v = 0;
do{
v = 10 * v + (int)(_curr - '0');
this.ReadChar();
} while (char.IsDigit(_curr));
if (_curr != '.') return new Num(v);
float f = v;
for (float d = 10; ; d *= 10)
{
this.ReadChar();
if (!char.IsDigit(_curr)) break;
f += (int)(_curr - 48) / d;
}
return new Real(f);
}
//for identifiers
if (char.IsLetter(_curr))
{
var b = new StringBuilder();
do
{
b.Append(_curr);
this.ReadChar();
} while (char.IsLetterOrDigit(_curr));
var s = b.ToString();
if (KeyWords.ContainsKey(s)) return KeyWords[s];
else return KeyWords[s] = new Word(s, Tag.ID);
}
//for the rest
var tok = new Token(_curr);
if (!this.EofReached) _curr = ' ';
return tok;
}
private void Reserve(Word word)
{
KeyWords.Add(word.Lexeme, word);
}
