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Viewing changes to src/lib/graut/walk.coffee

  • Committer: Peter S. May
  • Date: 2012-11-21 03:01:39 UTC
  • Revision ID: peter_s._may_httppsmay.com-20121121030139-71h0dbelgrcr9aye
model.coffee : Made the nodes visitors.
walk.coffee : Began writing as visitable.

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src/lib/graut/walk.coffee
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###
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Model = require './model'
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exports.walk = (top) ->
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        # TODO
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        throw Error "TODO"
 
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{ InterpolatedValue, StringValue, ListValue, InlineOp, ExpandOp, CallOp, NonceOp, semanticError } = Model
 
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callUnhandled = (obj) -> @unhandled obj
 
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class Visitable
 
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        constructor : (overrides) ->
 
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                overrides ?= {}
 
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                for own k, v of overrides
 
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                        @[k] = v
 
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        unhandled : (obj) -> semanticError obj, "Unexpected item"
 
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        interpolatedValue : callUnhandled
 
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        stringValue : callUnhandled
 
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        listValue : callUnhandled
 
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        inlineOp : callUnhandled
 
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        expandOp : callUnhandled
 
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        callOp : callUnhandled
 
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        nonceOp : callUnhandled
 
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walkVisitable = new Visitable
 
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        interpolatedValue : (node) -> walkInterpolated node
 
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exports.walk = (top) -> top.visit walkVisitable
 
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interpElementVisitable = new Visitable
 
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        stringValue : (node) -> textOfStringValue node
 
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        callOp : (node) -> walkCallOp node
 
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walkInterpolated = (node) -> node.visit interpElementVisitable
 
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codepointToString = (cp) ->
 
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        adj = (cp - 0x10000) & 0xFFFFF
 
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        throw Error("Invalid codepoint " + cp) if cp isnt (adj + 0x10000)
 
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        hi = adj >> 10
 
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        lo = adj & 0x3FF
 
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        String.fromCharCode(0xD800 + hi) + String.fromCharCode(0xDC00 + lo)
 
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stringTextVisitable = new Visitable
 
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        stringValue : (node) ->
 
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                text = node.textToken.text
 
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                if node.doBslashEscapes
 
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                        text = text.replace ///
 
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                                \\(?:
 
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                                        U([0-9A-Fa-f]{8}) |
 
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                                        u(?:
 
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                                                ([0-9A-Fa-f]{4})
 
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                                                \{ ([0-9A-Fa-f]+) \}
 
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                                        ) |
 
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                                        x([0-9A-Fa-f]{2}) |
 
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                                        ([bfnrt0]) |
 
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                                        ([\s\S])
 
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                                ) ///g,
 
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                                (fullMatch, x8, x4, xarb, x2, letter, any) ->
 
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                                        hex = x8 ? x4 ? xarb ? x2
 
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                                        if hex?
 
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                                                codepointToString parseInt hex, 16
 
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                                        else if letter?
 
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                                                switch letter
 
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                                                        when "b" then "\b"
 
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                                                        when "f" then "\f"
 
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                                                        when "n" then "\n"
 
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                                                        when "r" then "\r"
 
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                                                        when "t" then "\t"
 
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                                                        when "0" then "\0"
 
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                                        else
 
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                                                any
 
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                text
 
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textOfStringValue = (node) -> node.visit stringTextVisitable
 
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