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1 "{ Package: 'stx:libcomp' }" |
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2 |
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3 "{ NameSpace: Smalltalk }" |
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4 |
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5 ParseNodeVisitor subclass:#PluggableParseNodeVisitor |
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6 instanceVariableNames:'actionsPerNodeType' |
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7 classVariableNames:'' |
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8 poolDictionaries:'' |
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9 category:'System-Compiler-Support' |
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10 ! |
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11 |
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12 !PluggableParseNodeVisitor class methodsFor:'documentation'! |
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13 |
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14 documentation |
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15 " |
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16 a pluggable node visitor. |
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17 setup with: |
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18 actionForNodeClass:aClass put:aBlock |
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19 |
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20 for example, if you are only interested in assignments, |
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21 use the following code: |
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22 |v| |
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23 v := PluggableParseNodeVisitor new. |
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24 v actionForNodeClass:AssignmentNode put:[:node | Transcript showCR:node. true]. |
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25 v visit:(Parser parse:code in:someClass. |
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26 " |
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27 ! ! |
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28 |
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29 !PluggableParseNodeVisitor methodsFor:'setup'! |
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30 |
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31 actionForNodeClass:aNodeClass put:aBlock |
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32 "setup so that for nodes of type aNodeClass, aBlock is invoked. |
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33 If the block returns true, subnodes (eg. right side of assignments, etc.) |
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34 will be enumerated as well. |
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35 Otherwise, no subnodes are visited." |
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36 |
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37 actionsPerNodeType isNil ifTrue:[ |
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38 actionsPerNodeType := Dictionary new. |
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39 ]. |
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40 actionsPerNodeType at:aNodeClass put:aBlock |
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41 ! ! |
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42 |
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43 !PluggableParseNodeVisitor methodsFor:'visiting'! |
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44 |
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45 visit:aNodeObject |
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46 "redefined to look for an action for this node's class. |
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47 If there is one, it can specify if subnodes are to be visited too" |
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48 |
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49 |action| |
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50 |
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51 action := actionsPerNodeType at:aNodeObject class. |
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52 action notNil ifTrue:[ |
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53 (action value:aNodeObject) ifFalse:[^ self]. |
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54 ]. |
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55 super visit:aNodeObject |
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56 ! ! |
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57 |
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58 !PluggableParseNodeVisitor class methodsFor:'documentation'! |
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59 |
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60 version |
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61 ^ '$Header$' |
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62 ! |
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63 |
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64 version_CVS |
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65 ^ '$Header$' |
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66 ! ! |
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67 |