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one more bit to pass -- futzing with the if/else chains

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This commit is contained in:
Jeremy Ashkenas
2010-02-12 23:35:03 -05:00
parent ee1c9b284a
commit 066ee52615
7 changed files with 36 additions and 27 deletions
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10
src/grammar.coffee
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@@ -412,7 +412,11 @@ grammar: {
# The most basic form of "if".
IfBlock: [
o "IF Expression Block", -> new IfNode($2, $3)
o "IF Expression Block ElsIfs", -> (new IfNode($2, $3)).add_else($4)
]
IfChain: [
o "IfBlock", -> $1
o "IfBlock ElsIfs", -> $1.add_else($2)
]
ElsIf: [
@@ -427,8 +431,8 @@ grammar: {
# The full complement of if blocks, including postfix one-liner ifs and unlesses.
If: [
o "IfBlock", -> $1
o "IfBlock ELSE Block", -> $1.add_else($3)
o "IfChain", -> $1
o "IfChain ELSE Block", -> $1.add_else($3)
o "Expression IF Expression", -> new IfNode($3, Expressions.wrap([$1]), null, {statement: true})
o "Expression UNLESS Expression", -> new IfNode($3, Expressions.wrap([$1]), null, {statement: true, invert: true})
]

2
src/lexer.coffee
View File

@@ -105,7 +105,7 @@ lex::identifier_token: ->
@tokens.splice(-2, 1)
else
@tag(1, 'PROPERTY_ACCESS')
if tag is 'ELSE' and @tag() is 'IF'
if tag is 'IF' and @tag() is 'ELSE'
@tag(1, 'ELSIF')
else
@token(tag, id)

7
src/rewriter.coffee
View File

@@ -14,7 +14,7 @@ EXPRESSION_START: pair[0] for pair in BALANCED_PAIRS
EXPRESSION_TAIL: pair[1] for pair in BALANCED_PAIRS
# Tokens that indicate the close of a clause of an expression.
EXPRESSION_CLOSE: ['CATCH', 'WHEN', 'ELSE', 'FINALLY'].concat(EXPRESSION_TAIL)
EXPRESSION_CLOSE: ['CATCH', 'WHEN', 'ELSE', 'ELSIF', 'FINALLY'].concat(EXPRESSION_TAIL)
# Tokens pairs that, in immediate succession, indicate an implicit call.
IMPLICIT_FUNC: ['IDENTIFIER', 'SUPER', ')', 'CALL_END', ']', 'INDEX_END']
@@ -33,7 +33,7 @@ for pair in BALANCED_PAIRS
# Single-line flavors of block expressions that have unclosed endings.
# The grammar can't disambiguate them, so we insert the implicit indentation.
SINGLE_LINERS: ['ELSE', "->", "=>", 'TRY', 'FINALLY', 'THEN']
SINGLE_CLOSERS: ['TERMINATOR', 'CATCH', 'FINALLY', 'ELSE', 'OUTDENT', 'LEADING_WHEN', 'PARAM_START']
SINGLE_CLOSERS: ['TERMINATOR', 'CATCH', 'FINALLY', 'ELSE', 'ELSIF', 'OUTDENT', 'LEADING_WHEN', 'PARAM_START']
# Rewrite the token stream in multiple passes, one logical filter at
# a time. This could certainly be changed into a single pass through the
@@ -160,8 +160,7 @@ re::add_implicit_parentheses: ->
# ')' can close a single-line block, but we need to make sure it's balanced.
re::add_implicit_indentation: ->
this.scan_tokens (prev, token, post, i) =>
return 1 unless SINGLE_LINERS.indexOf(token[0]) >= 0 and post[0] isnt 'INDENT' and
not (token[0] is 'ELSE' and post[0] is 'IF')
return 1 unless SINGLE_LINERS.indexOf(token[0]) >= 0 and post[0] isnt 'INDENT'
starter: token[0]
this.tokens.splice(i + 1, 0, ['INDENT', 2, token[2]])
idx: i + 1