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Diffstat (limited to 'docs/devel_guide_src/flowControl.tex')
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diff --git a/docs/devel_guide_src/flowControl.tex b/docs/devel_guide_src/flowControl.tex new file mode 100755 index 0000000..936df67 --- /dev/null +++ b/docs/devel_guide_src/flowControl.tex @@ -0,0 +1,360 @@ +\section{Directives: Flow Control} +\label{flowControl} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#for} +\label{flowControl.for} + +The template: +\begin{verbatim} +#for $i in $range(10) +$i #slurp +#end for +\end{verbatim} + +The output: +\begin{verbatim} +0 1 2 3 4 5 6 7 8 9 +\end{verbatim} + +The generated code: +\begin{verbatim} +for i in range(10): + write(filter(i)) # generated from '$i' at line 2, col 1. + write(' ') +\end{verbatim} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#repeat} +\label{flowControl.repeat} + +The template: +\begin{verbatim} +#repeat 3 +My bonnie lies over the ocean +#end repeat +O, bring back my bonnie to me! +\end{verbatim} + +The output: +\begin{verbatim} +My bonnie lies over the ocean +My bonnie lies over the ocean +My bonnie lies over the ocean +O, bring back my bonnie to me! +\end{verbatim} +(OK, so the second line should be ``sea'' instead of ``ocean''.) + +The generated code: +\begin{verbatim} +for __i0 in range(3): + write('My bonnie lies over the ocean\n') +write('O, bring back my bonnie to me!\n') +\end{verbatim} + +Note that a new local variable of the form \code{\_\_i\$num} will be +used for each instance of \code{repeat} in order to permit nesting. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#while} +\label{flowControl.while} + +The template: +\begin{verbatim} +#set $alive = True +#while $alive +I am alive! +#set $alive = False +#end while +\end{verbatim} + +The output: +\begin{verbatim} +I am alive! +\end{verbatim} + +The generated code: +\begin{verbatim} +alive = True +while alive: + write('I am alive!\n') + alive = False +\end{verbatim} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#if} +\label{} + +The template: +\begin{verbatim} +#set $size = 500 +#if $size >= 1500 +It's big +#else if $size < 1500 and $size > 0 +It's small +#else +It's not there +#end if +\end{verbatim} + +The output: +\begin{verbatim} +It's small +\end{verbatim} + +The generated code: +\begin{verbatim} +size = 500 +if size >= 1500: + write("It's big\n") +elif size < 1500 and size > 0: + write("It's small\n") +else: + write("It's not there\n") +\end{verbatim} + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#unless} +\label{flowControl.unless} + +The template: +\begin{verbatim} +#set $count = 9 +#unless $count + 5 > 15 +Count is in range. +#end unless +\end{verbatim} + +The output: +\begin{verbatim} +Count is in range. +\end{verbatim} + +The generated code: +\begin{verbatim} + count = 9 + if not (count + 5 > 15): + write('Count is in range.\n') +\end{verbatim} + +{\em Note:} There is a bug in Cheetah 0.9.13. It's forgetting the +parentheses in the \code{if} expression, which could lead to it calculating +something different than it should. + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#break and \#continue} +\label{flowControl.break} + +The template: +\begin{verbatim} +#for $i in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 'James', 'Joe', 'Snow'] +#if $i == 10 + #continue +#end if +#if $i == 'Joe' + #break +#end if +$i - #slurp +#end for +\end{verbatim} + +The output: +\begin{verbatim} +1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 11 - 12 - James - +\end{verbatim} + +The generated code: +\begin{verbatim} +for i in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 'James', 'Joe', 'Snow']: + if i == 10: + write('') + continue + if i == 'Joe': + write('') + break + write(filter(i)) # generated from '$i' at line 8, col 1. + write(' - ') +\end{verbatim} + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#pass} +\label{flowControl.pass} + +The template: +\begin{verbatim} +Let's check the number. +#set $size = 500 +#if $size >= 1500 +It's big +#elif $size > 0 +#pass +#else +Invalid entry +#end if +Done checking the number. +\end{verbatim} + +The output: +\begin{verbatim} +Let's check the number. +Done checking the number. +\end{verbatim} + +The generated code: +\begin{verbatim} +write("Let's check the number.\n") +size = 500 +if size >= 1500: + write("It's big\n") +elif size > 0: + pass +else: + write('Invalid entry\n') +write('Done checking the number.\n') +\end{verbatim} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#stop} +\label{flowControl.stop} + +The template: +\begin{verbatim} +A cat +#if 1 + sat on a mat + #stop + watching a rat +#end if +in a flat. +\end{verbatim} + +The output: +\begin{verbatim} +A cat + sat on a mat +\end{verbatim} + +The generated code: +\begin{verbatim} +write('A cat\n') +if 1: + write(' sat on a mat\n') + if dummyTrans: + return trans.response().getvalue() + else: + return "" + write(' watching a rat\n') +write('in a flat.\n') +\end{verbatim} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +\subsection{\#return} +\label{flowControl.return} + +The template: +\begin{verbatim} +1 +$test[1] +3 +#def test +1.5 +#if 1 +#return '123' +#else +99999 +#end if +#end def +\end{verbatim} + +The output: +\begin{verbatim} +1 +2 +3 +\end{verbatim} + +The generated code: +\begin{verbatim} + def test(self, + trans=None, + dummyTrans=False, + VFS=valueFromSearchList, + VFN=valueForName, + getmtime=getmtime, + currentTime=time.time): + + + """ + Generated from #def test at line 5, col 1. + """ + + if not trans: + trans = DummyTransaction() + dummyTrans = True + write = trans.response().write + SL = self._searchList + filter = self._currentFilter + globalSetVars = self._globalSetVars + + ######################################## + ## START - generated method body + + write('1.5\n') + if 1: + return '123' + else: + write('99999\n') + + ######################################## + ## END - generated method body + + if dummyTrans: + return trans.response().getvalue() + else: + return "" +\end{verbatim} +\begin{verbatim} + def respond(self, + trans=None, + dummyTrans=False, + VFS=valueFromSearchList, + VFN=valueForName, + getmtime=getmtime, + currentTime=time.time): + + + """ + This is the main method generated by Cheetah + """ + + if not trans: + trans = DummyTransaction() + dummyTrans = True + write = trans.response().write + SL = self._searchList + filter = self._currentFilter + globalSetVars = self._globalSetVars + + ######################################## + ## START - generated method body + + write('\n1\n') + write(filter(VFS(SL,"test",1)[1])) # generated from '$test[1]' at line 3, col 1. + write('\n3\n') + + ######################################## + ## END - generated method body + + if dummyTrans: + return trans.response().getvalue() + else: + return "" +\end{verbatim} + + +% Local Variables: +% TeX-master: "devel_guide" +% End: |