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Merge pull request #86 from VitorCBSB/master

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Chapter 5: Fixed Type Mismatch message for If.
This commit is contained in:
Stephen Diehl 2016-07-11 14:12:41 -04:00 committed by GitHub
commit 5c515bd386
2 changed files with 3 additions and 3 deletions
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4
004_type_systems.md
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@ -404,7 +404,7 @@ typeof expr = case expr of
then throwError $ TypeMismatch ta TBool
else
if tb /= tc
then throwError $ TypeMismatch ta tb
then throwError $ TypeMismatch tb tc
else return tc
Tr -> return TBool
@ -484,7 +484,7 @@ We can consider a very simple type system for our language that will consist of
$$
\begin{aligned}
\tau :=\ & \t{Int} \\
& \t{Bool} \\
& \t{Bool} \\
& \tau \rightarrow \tau \\
\end{aligned}
$$

2
chapter5/calc_typed/Check.hs
View File

@ -48,7 +48,7 @@ typeof expr = case expr of
then throwError $ TypeMismatch ta TBool
else
if tb /= tc
then throwError $ TypeMismatch ta tb
then throwError $ TypeMismatch tb tc
else return tc
check :: Expr -> Either TypeError Type