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use expr_or_block where appropriate

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This commit is contained in:
greg 2018-08-19 15:58:31 -07:00
parent 0e914cf057
commit f9181b5786
1 changed files with 27 additions and 9 deletions
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36
schala-lang/src/parsing.rs
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@ -240,19 +240,17 @@ record_pattern := IDENTIFIER '{' (record_pattern_entry, ',')* '}'
record_pattern_entry := IDENTIFIER | IDENTIFIER ':' Pattern
tuple_struct_pattern := IDENTIFIER '(' (pattern, ',')* ')'
//TODO when this works bring it to guard_arm
expr_or_block := '{' (statement delimiter)* '}' | expr
/* Expression - If */
if_expr := 'if' discriminator ('then' condititional | 'is' simple_pattern_match | guard_block)
discriminator := modified_precedence_expression
modified_precedence_expression := precedence_expr (operator)+ //TODO this is currently hard, rearchitect things
conditional := block else_clause
conditional := expr_or_block else_clause
simple_pattern_match := pattern 'then' conditional
else_clause := ε | 'else' block
else_clause := ε | 'else' expr_or_block
guard_block := '{' (guard_arm, ',')* '}'
guard_arm := guard '->' block
guard_arm := guard '->' expr_or_block
guard := 'is' pattern | (operator)+ precedence_expr
/* Expression - While */
@ -667,7 +665,7 @@ impl Parser {
parse_method!(conditional(&mut self) -> ParseResult<IfExpressionBody> {
expect!(self, Keyword(Kw::Then));
let then_clause = self.block()?; //TODO should be block_or_expr
let then_clause = self.expr_or_block()?;
let else_clause = self.else_clause()?;
Ok(IfExpressionBody::SimpleConditional(then_clause, else_clause))
});
@ -676,7 +674,7 @@ impl Parser {
expect!(self, Keyword(Kw::Is));
let pat = self.pattern()?;
expect!(self, Keyword(Kw::Then));
let then_clause = self.block()?; //TODO should be block_or_expr
let then_clause = self.expr_or_block()?;
let else_clause = self.else_clause()?;
Ok(IfExpressionBody::SimplePatternMatch(pat, then_clause, else_clause))
});
@ -684,7 +682,7 @@ impl Parser {
parse_method!(else_clause(&mut self) -> ParseResult<Option<Block>> {
Ok(if let Keyword(Kw::Else) = self.peek() {
self.next();
Some(self.block()?)
Some(self.expr_or_block()?)
} else {
None
})
@ -699,7 +697,7 @@ impl Parser {
let guard = self.guard()?;
expect!(self, Operator(ref c) if **c == "->");
println!("WE HIIII? {:?}", self.peek());
let body = self.block()?;
let body = self.expr_or_block()?;
Ok(GuardArm { guard, body })
});
@ -771,6 +769,16 @@ impl Parser {
Ok(delimited!(self, LCurlyBrace, statement, Newline | Semicolon, RCurlyBrace, nonstrict))
});
parse_method!(expr_or_block(&mut self) -> ParseResult<Block> {
match self.peek() {
LCurlyBrace => self.block(),
_ => {
let expr = self.expression()?;
Ok(vec![Statement::ExpressionStatement(expr)])
}
}
});
parse_method!(while_expr(&mut self) -> ParseResult<Expression> {
use self::ExpressionType::*;
expect!(self, Keyword(Kw::While));
@ -1408,6 +1416,16 @@ fn a(x) {
])
}
parse_test! {
"if x is Some(a) then 4 else 9", AST(vec![
exprstatement!(
IfExpression {
discriminator: bx!(Discriminator::Simple(ex!(Value(rc!(x))))),
body: bx!(IfExpressionBody::SimplePatternMatch(Pattern::TupleStruct(rc!(Some), vec![Pattern::Literal(PatternLiteral::VarPattern(rc!(a)))]), vec![exprstatement!(NatLiteral(4))], Some(vec![exprstatement!(NatLiteral(9))]))) }
)
])
}
parse_test! {
"if x is Something { a, b: x } then { 4 } else { 9 }", AST(vec![
exprstatement!(