public void SetLookahead()
{
var set1 = ParseItemSet.New(new ParseItem[] { _item10, _item11, _item20 });
var la1 = SegmentSet.New(new Segment[] { _lookaheadA, _lookaheadB });
var la2 = SegmentSet.New(new Segment[] { _lookaheadB, _lookaheadC });
Assert.That(set1.GetLookahead(_item10), Is.EqualTo(SegmentSet.EmptySet));
Assert.That(set1.GetLookahead(_item11), Is.EqualTo(SegmentSet.EmptySet));
Assert.That(set1.GetLookahead(_item20), Is.EqualTo(SegmentSet.EmptySet));
set1.SetLookahead(_item10, la1);
set1.SetLookahead(_item11, la1);
Assert.That(set1.GetLookahead(_item10), Is.EqualTo(la1));
Assert.That(set1.GetLookahead(_item11), Is.EqualTo(la1));
Assert.That(set1.GetLookahead(_item20), Is.EqualTo(SegmentSet.EmptySet));
set1.SetLookahead(_item10, la2);
Assert.That(set1.GetLookahead(_item10), Is.EqualTo(la2));
Assert.That(set1.GetLookahead(_item11), Is.EqualTo(la1));
Assert.That(set1.GetLookahead(_item20), Is.EqualTo(SegmentSet.EmptySet));
}
Config ConstructSample2()
{
/*
* S := "id"
* | V ":=" E
*
* V := "id"
*
* E := V
* | "n"
*/
var s = new Segment("S", false);
var v = new Segment("V", false);
var e = new Segment("E", false);
var id = new Segment("id", true);
var assign = new Segment(":=", true);
var n = new Segment("n", true);
return(new Config()
{
TopLevelSegments = SegmentSet.New(new Segment[] { s, e, }),
Productions =
{
new ConfigProduction()
{
Target = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "S"),
Segment = s,
Rules =
{
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, "id"),
Segment = id,
},
},
Production = new Production(s, ImmutableArray.Create(id)),
},
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "V"),
Segment = v,
},
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, ":="),
Segment = assign,
},
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "E"),
Segment = e,
},
},
Production = new Production(s, ImmutableArray.Create(v, assign, e)),
},
},
},
new ConfigProduction()
{
Target = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "V"),
Segment = v,
Rules =
{
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, "id"),
Segment = id,
},
},
Production = new Production(v, ImmutableArray.Create(id)),
},
},
},
new ConfigProduction()
{
Target = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "E"),
Segment = e,
Rules =
{
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "V"),
Segment = v,
},
},
Production = new Production(e, ImmutableArray.Create(v)),
},
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, "n"),
Segment = n,
},
},
Production = new Production(e, ImmutableArray.Create(n)),
},
},
},
},
});
}
Config ConstructSample1()
{
/*
* A := "(" A ")"
* | "a"
*/
var nonTerminal = new Segment("A", false);
var terminal = new Segment("a", true);
var openParen = new Segment("(", true);
var closeParen = new Segment(")", true);
return(new Config()
{
TopLevelSegments = SegmentSet.New(new Segment[] { nonTerminal }),
Productions =
{
new ConfigProduction()
{
Target = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "A"),
Segment = nonTerminal,
Rules =
{
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, "("),
Segment = openParen,
},
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.NonTerminal, null, null, "A"),
Segment = nonTerminal,
},
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, ")"),
Segment = closeParen,
},
},
Production = new Production(nonTerminal, ImmutableArray.Create(openParen, nonTerminal, closeParen)),
},
new ConfigRule()
{
Segments =
{
new ConfigSegment()
{
Token = new ConfigToken(ConfigTokenType.Label, null, null, "a"),
Segment = terminal,
},
},
Production = new Production(nonTerminal, ImmutableArray.Create(terminal)),
},
},
},
},
});
}
