📄 sec-happy-ghci.html
字号:
<HTML
><HEAD
><TITLE
>Using Happy with GHCi</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.74b"><LINK
REL="HOME"
TITLE="Happy User Guide"
HREF="happy.html"><LINK
REL="UP"
TITLE="Tips"
HREF="sec-tips.html"><LINK
REL="PREVIOUS"
TITLE="Conflict Tips"
HREF="sec-conflict-tips.html"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>Happy User Guide</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="sec-conflict-tips.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 6. Tips</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
> </TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="SEC-HAPPY-GHCI"
>6.5. Using Happy with <SPAN
CLASS="APPLICATION"
>GHCi</SPAN
></A
></H1
><P
><SPAN
CLASS="APPLICATION"
>GHCi</SPAN
>'s compilation manager
doesn't understand Happy grammars, but with some creative use of
macros and makefiles we can give the impression that
<SPAN
CLASS="APPLICATION"
>GHCi</SPAN
> is invoking Happy
automatically:</P
><P
></P
><UL
><LI
><P
>Create a simple makefile, called
<TT
CLASS="FILENAME"
>Makefile_happysrcs</TT
>:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="90%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>HAPPY = happy
HAPPY_OPTS =
all: MyParser.y
%.hs: %.y
$(HAPPY) $(HAPPY_OPTS) $< -o $@</PRE
></TD
></TR
></TABLE
></LI
><LI
><P
>Create a macro in GHCi to replace the
<TT
CLASS="LITERAL"
>:reload</TT
> command, like so (type this all
on one line):</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="90%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>:def rh (\_ -> System.system "make -f Makefile_happysrcs"
>>= \rr -> case rr of { System.ExitSuccess -> return ":reload" ;
_ -> return "" })</PRE
></TD
></TR
></TABLE
></LI
><LI
><P
>Use <TT
CLASS="LITERAL"
>:myreload</TT
>
(<TT
CLASS="LITERAL"
>:my</TT
> will do) instead of
<TT
CLASS="LITERAL"
>:reload</TT
> (<TT
CLASS="LITERAL"
>:r</TT
>).</P
></LI
></UL
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="sec-conflict-tips.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="happy.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
> </TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Conflict Tips</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="sec-tips.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
> </TD
></TR
></TABLE
></DIV
></BODY
></HTML
>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -