92 lines
2.1 KiB
D
92 lines
2.1 KiB
D
|
#!/usr/bin/env dub
|
||
|
|
/+ dub.json:
|
||
|
|
{
|
||
|
|
"name": "math",
|
||
|
|
"dependencies": {
|
||
|
|
"dast": {"path": "../"}
|
||
|
|
}
|
||
|
|
} +/
|
||
|
|
|
||
|
|
import std;
|
||
|
|
import dast.parse,
|
||
|
|
dast.tokenize;
|
||
|
|
|
||
|
|
enum TokenType {
|
||
|
|
@TextAllMatcher!isDigit Number,
|
||
|
|
|
||
|
|
@TextCompleteMatcher!"+" Add,
|
||
|
|
@TextCompleteMatcher!"-" Sub,
|
||
|
|
@TextCompleteMatcher!"*" Mul,
|
||
|
|
@TextCompleteMatcher!"/" Div,
|
||
|
|
|
||
|
|
@TextCompleteMatcher!"(" OpenParen,
|
||
|
|
@TextCompleteMatcher!")" CloseParen,
|
||
|
|
|
||
|
|
End,
|
||
|
|
}
|
||
|
|
alias Token = dast.tokenize.Token!(TokenType, string);
|
||
|
|
|
||
|
|
struct Whole {
|
||
|
|
int result;
|
||
|
|
}
|
||
|
|
struct TermList {
|
||
|
|
int value;
|
||
|
|
}
|
||
|
|
struct Term {
|
||
|
|
int value;
|
||
|
|
}
|
||
|
|
|
||
|
|
class RuleSet {
|
||
|
|
public:
|
||
|
|
@ParseRule:
|
||
|
|
static Whole ParseWhole(TermList terms, @(TokenType.End) Token) {
|
||
|
|
return Whole(terms.value);
|
||
|
|
}
|
||
|
|
|
||
|
|
static TermList ParseTermListFromAddedNextTerm(
|
||
|
|
TermList lterms, @(TokenType.Add) Token, Term term) {
|
||
|
|
return TermList(lterms.value + term.value);
|
||
|
|
}
|
||
|
|
static TermList ParseTermListFromSubtractedNextTerm(
|
||
|
|
TermList lterms, @(TokenType.Sub) Token, Term term) {
|
||
|
|
return TermList(lterms.value - term.value);
|
||
|
|
}
|
||
|
|
static TermList ParseTermListFirstItem(Term term) {
|
||
|
|
return TermList(term.value);
|
||
|
|
}
|
||
|
|
|
||
|
|
static Term ParseTermFromFirstNumber(@(TokenType.Number) Token num) {
|
||
|
|
return Term(num.text.to!int);
|
||
|
|
}
|
||
|
|
|
||
|
|
static Term ParseTermFromTermList(
|
||
|
|
@(TokenType.OpenParen) Token, TermList terms, @(TokenType.CloseParen) Token) {
|
||
|
|
return Term(terms.value);
|
||
|
|
}
|
||
|
|
static Term ParseMultipledTerm(
|
||
|
|
Term lterm, @(TokenType.Mul) Token, @(TokenType.Number) Token num) {
|
||
|
|
return Term(lterm.value * num.text.to!int);
|
||
|
|
}
|
||
|
|
static Term ParseDividedTerm(
|
||
|
|
Term lterm, @(TokenType.Div) Token, @(TokenType.Number) Token num) {
|
||
|
|
return Term(lterm.value / num.text.to!int);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void main(string[] args) {
|
||
|
|
assert(args.length == 2);
|
||
|
|
|
||
|
|
// PrintItemSet!(TokenType, RuleSet, Whole);
|
||
|
|
|
||
|
|
try {
|
||
|
|
args[1].
|
||
|
|
Tokenize!TokenType.
|
||
|
|
chain([Token("", TokenType.End)]).
|
||
|
|
Parse!Whole(cast(RuleSet) null).
|
||
|
|
result.writeln;
|
||
|
|
} catch (ParseException!Token e) {
|
||
|
|
"%s at token '%s' [%s] at (%d, %d)".
|
||
|
|
writefln(e.msg, e.token.text, e.token.type, e.token.pos.stline, e.token.pos.stchar);
|
||
|
|
}
|
||
|
|
}
|