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svc-api-x/v1/lib/expression_parser.cfc

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<cfcomponent>
<cfset this.args = []/>
<cfproperty name="entity" type="string"/>
<cffunction name="init">
<cfargument name="entity" type="string" default="instance_operation_cfs_param"/>
<cfset this.entity=arguments.entity/>
<cfreturn this>
</cffunction>
<cffunction name="eval" returntype="any" access="public">
<cfargument name="expression" type="string"/>
<cfargument name="context" type="any"/>
<cfset var args=[]/>
<cfset parse(args, tokenize(arguments.expression),0)/>
<cfreturn computeExpression(args[1].function, args[1].args, arguments.context)/>
</cffunction>
<cffunction name="extractParams" returntype="any" access="public">
<cfargument name="expression" type="string"/>
<cfset var params=[]/>
<cfset parseForParams(params, tokenize(arguments.expression),0)/>
<cfreturn params/>
</cffunction>
<cffunction name="tokenize" returntype="array" access="private">
<cfargument name="expression" type="string"/>
<cfset var local={}/>
<cfset var pattern='"(.*?)"|\w+(\s*\.\s*\w+)*|\(|\)'/>
<cfset var res=rematch(pattern,expression)/>
<cfset var tokens = []/>
<cfloop array=#res# item="local.t">
<cfset tmp=trim(local.t)/>
<cfif len(tmp)>
<cfset arrayAppend(tokens,tmp)/>
</cfif>
</cfloop>
<cfreturn tokens/>
</cffunction>
<cffunction name="tokenType" output=false access="private">
<cfargument name="token"/>
<cfif token EQ "(">
<cfreturn "("/>
<cfelseif token EQ ")">
<cfreturn ")"/>
<cfelseif left(token,1) EQ '"'>
<cfreturn "string"/>
<cfelseif find(".",token)>
<cfreturn "variable"/>
<cfelse>
<cfreturn "function"/>
</cfif>
</cffunction>
<cffunction name="parse" returntype="numeric" access="private">
<cfargument name="args" type="array"/>
<cfargument name="tokens" type="array"/>
<cfargument name="positionBefore" type="numeric"/>
<cfset var i = arguments.positionBefore/>
<cfloop condition="++i LE arrayLen(arguments.tokens)">
<cfswitch expression=#tokenType(arguments.tokens[i])#>
<cfcase value="string">
<cfset arrayAppend(arguments.args,mid(arguments.tokens[i],2,len(arguments.tokens[i])-2))/>
</cfcase>
<cfcase value="variable">
<cfset arrayAppend( arguments.args, {"function"="getValue","args"=[tokens[i]]} )/>
</cfcase>
<cfcase value="function">
<cfset var f = {"function"=arguments.tokens[i],"args"=[]}/>
<cfif i GE arrayLen(arguments.tokens)>
<cfthrow message="unexpected end of expression"/>
</cfif>
<cfif #tokenType(arguments.tokens[++i])# NEQ "(">
<cfthrow message="function syntax incorrect" detail="function #arguments.tokens[i-1]#, token='#arguments.tokens[i]#' (#arrayToList(tokens,' ')#"/>
</cfif>
<cfset i = parse(f.args, arguments.tokens, i)/>
<cfset arrayAppend(arguments.args,f)/>
</cfcase>
<cfcase value=")">
<cfreturn i/>
</cfcase>
</cfswitch>
</cfloop>
</cffunction>
<cffunction name="parseForParams" returntype="numeric" access="private">
<cfargument name="args" type="array"/>
<cfargument name="tokens" type="array"/>
<cfargument name="positionBefore" type="numeric"/>
<cfset var i = arguments.positionBefore/>
<cfloop condition="++i LE arrayLen(arguments.tokens)">
<cfswitch expression=#tokenType(arguments.tokens[i])#>
<cfcase value="string">
</cfcase>
<cfcase value="variable">
<cfset arrayAppend( arguments.args, tokens[i] )/>
</cfcase>
<cfcase value="function">
<cfset var f = {"function"=arguments.tokens[i],"args"=[]}/>
<cfif i GE arrayLen(arguments.tokens)>
<cfthrow message="unexpected end of expression"/>
</cfif>
<cfif #tokenType(arguments.tokens[++i])# NEQ "(">
<cfthrow message="function syntax incorrect" detail="function #arguments.tokens[i-1]#, token='#arguments.tokens[i]#' (#arrayToList(tokens,' ')#"/>
</cfif>
<cfset i = parseForParams(f.args, arguments.tokens, i)/>
</cfcase>
<cfcase value=")">
<cfreturn i/>
</cfcase>
</cfswitch>
</cfloop>
</cffunction>
<cffunction name="computeExpression" returntype="any" access="private">
<cfargument name="function" type="string"/>
<cfargument name="args" type="array"/>
<cfargument name="context" type="any"/>
<cfloop index="i" from=1 to=#arrayLen(arguments.args)#>
<cfif isStruct(arguments.args[i]) AND structKeyExists(arguments.args[i],"function")>
<cfset arguments.args[i] = computeExpression(
arguments.args[i].function,
arguments.args[i].args,
arguments.context
) />
</cfif>
</cfloop>
<cfreturn executeFunction(arguments.function,arguments.args,arguments.context)/>
</cffunction>
<cffunction name="executeFunction" returntype="any" access="private">
<cfargument name="functionName"/>
<cfargument name="args" type="array"/>
<cfargument name="context" type="any"/>
<cfset var obj = createObject("component", arguments.context.component).init(arguments.context.keys, arguments.context.params)/>
<cfreturn invoke(obj, functionName, args)/>
</cffunction>
</cfcomponent>