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whitespace parser down to 4 shift/reduce errors -- good enough for me

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This commit is contained in:
Jeremy Ashkenas
2009-12-29 21:46:15 -05:00
parent fd357871f2
commit 541291e2f3
1 changed files with 61 additions and 55 deletions
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116
lib/coffee_script/grammar.y
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@@ -32,15 +32,15 @@ prechigh
left '.'
right INDENT
left OUTDENT
right THROW FOR IN WHILE WHEN NEW SUPER
left UNLESS IF ELSE EXTENDS
right THROW FOR IN WHILE WHEN NEW SUPER IF THEN ELSE
left UNLESS EXTENDS
left ASSIGN '||=' '&&='
right RETURN
right RETURN '=>'
preclow
# We expect 3 shift/reduce errors for optional syntax.
# We expect 4 shift/reduce errors for optional syntax.
# There used to be 252 -- greatly improved.
expect 3
expect 4
rule
@@ -61,22 +61,12 @@ rule
# All types of expressions in our language.
Expression:
PureExpression
| Statement
;
# The parts that are natural JavaScript expressions.
PureExpression:
Value
| Call
| Code
| Operation
| Range
;
# We have to take extra care to convert these statements into expressions.
Statement:
Assign
| Assign
| If
| Try
| Throw
@@ -140,36 +130,57 @@ rule
# For Ruby's Operator precedence, see:
# https://www.cs.auckland.ac.nz/references/ruby/ProgrammingRuby/language.html
Operation:
PrefixOperation
| InfixOperation
| PostfixOperation
;
'!' Expression { result = OpNode.new(val[0], val[1]) }
| '!!' Expression { result = OpNode.new(val[0], val[1]) }
| '-' Expression = UMINUS { result = OpNode.new(val[0], val[1]) }
| NOT Expression { result = OpNode.new(val[0], val[1]) }
| '~' Expression { result = OpNode.new(val[0], val[1]) }
| '--' Expression { result = OpNode.new(val[0], val[1]) }
| '++' Expression { result = OpNode.new(val[0], val[1]) }
| DELETE Expression { result = OpNode.new(val[0], val[1]) }
| TYPEOF Expression { result = OpNode.new(val[0], val[1]) }
| Expression '--' { result = OpNode.new(val[1], val[0], nil, true) }
| Expression '++' { result = OpNode.new(val[1], val[0], nil, true) }
PrefixOperation:
PrefixSymbol PureExpression { result = OpNode.new(val[0], val[1]) }
;
| Expression '*' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '/' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '%' Expression { result = OpNode.new(val[1], val[0], val[2]) }
PostfixOperation:
PureExpression PostfixSymbol { result = OpNode.new(val[1], val[0], nil, true) }
;
| Expression '+' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '-' Expression { result = OpNode.new(val[1], val[0], val[2]) }
InfixOperation:
PureExpression
InfixSymbol PureExpression { result = OpNode.new(val[1], val[0], val[2]) }
;
| Expression '<<' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '>>' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '>>>' Expression { result = OpNode.new(val[1], val[0], val[2]) }
PrefixSymbol:
'!' | '!!' | '-' = UMINUS | NOT | '~' | '--' | '++' | DELETE | TYPEOF
;
| Expression '&' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '|' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '^' Expression { result = OpNode.new(val[1], val[0], val[2]) }
PostfixSymbol:
'--' | '++'
;
| Expression '<=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '<' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '>' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '>=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
InfixSymbol:
'*' | '/' | '%' | '+' | '-' | '<<' | '>>' | '>>>' | '&' | '|' | '^'
| '<=' | '<' | '>' | '>=' | '==' | '!=' | IS | ISNT | '&&' | '||'
| AND | OR | '-=' | '+=' | '/=' | '*=' | '%=' | '||=' | '&&=' | INSTANCEOF
| Expression '==' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '!=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression IS Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression ISNT Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '&&' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '||' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression AND Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression OR Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '-=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '+=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '/=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '*=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '%=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '||=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression '&&=' Expression { result = OpNode.new(val[1], val[0], val[2]) }
| Expression INSTANCEOF Expression { result = OpNode.new(val[1], val[0], val[2]) }
;
# Function definition.
@@ -285,7 +296,7 @@ rule
# Throw an exception.
Throw:
THROW PureExpression { result = ThrowNode.new(val[1]) }
THROW Expression { result = ThrowNode.new(val[1]) }
;
# Parenthetical expressions.
@@ -295,7 +306,7 @@ rule
# The while loop. (there is no do..while).
While:
WHILE PureExpression Block { result = WhileNode.new(val[1], val[2]) }
WHILE Expression Block { result = WhileNode.new(val[1], val[2]) }
;
# Array comprehensions, including guard and current index.
@@ -314,8 +325,8 @@ rule
# The source of the array comprehension can optionally be filtered.
ForSource:
IN PureExpression { result = [val[1]] }
| IN PureExpression
IN Expression { result = [val[1]] }
| IN Expression
WHEN Expression { result = [val[1], val[3]] }
;
@@ -337,22 +348,17 @@ rule
# An individual when.
When:
WHEN PureExpression Block { result = IfNode.new(val[1], val[2], nil, {:statement => true}) }
| WHEN PureExpression
WHEN Expression Block { result = IfNode.new(val[1], val[2], nil, {:statement => true}) }
| WHEN Expression
THEN Expression Terminator { result = IfNode.new(val[1], val[3], nil, {:statement => true}) }
;
# All of the following nutso if-else destructuring is to make the
# grammar expand unambiguously.
# The condition itself.
IfClause:
IF PureExpression { result = val[1] }
;
IfBlock:
IfClause Block { result = IfNode.new(val[0], val[1]) }
| IfClause THEN Expression { result = IfNode.new(val[0], val[2]) }
IF Expression Block { result = IfNode.new(val[1], val[2]) }
| IF Expression THEN Expression { result = IfNode.new(val[1], val[3]) }
;
# An elsif portion of an if-else block.
@@ -381,8 +387,8 @@ rule
# The full complement of if blocks, including postfix one-liner ifs and unlesses.
If:
IfBlock IfEnd { result = val[0].add_else(val[1]) }
| Expression IfClause { result = IfNode.new(val[1], Expressions.new([val[0]]), nil, {:statement => true}) }
| Expression UNLESS PureExpression { result = IfNode.new(val[2], Expressions.new([val[0]]), nil, {:statement => true, :invert => true}) }
| Expression IF Expression { result = IfNode.new(val[2], Expressions.new([val[0]]), nil, {:statement => true}) }
| Expression UNLESS Expression { result = IfNode.new(val[2], Expressions.new([val[0]]), nil, {:statement => true, :invert => true}) }
;
end