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Diffstat (limited to 'ipl/procs/usage.icn')
| -rw-r--r-- | ipl/procs/usage.icn | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/ipl/procs/usage.icn b/ipl/procs/usage.icn new file mode 100644 index 0000000..f381c86 --- /dev/null +++ b/ipl/procs/usage.icn @@ -0,0 +1,68 @@ +############################################################################ +# +# File: usage.icn +# +# Subject: Procedures for service functions +# +# Author: Ralph E. Griswold +# +# Date: July 19, 1991 +# +############################################################################ +# +# This file is in the public domain. +# +############################################################################ +# +# These procedures provide various common services: +# +# Usage(s) stops executions with a message concerning the +# expected form of usage of a program. +# +# Error(L[]) writes arguments to &errout and returns. +# +# +# ErrorCheck(l,f) reports an error that has been converted to +# failure. +# +# Feature(s) succeeds if feature s is available in the running +# implementation of Icon. +# +# Requires(s) terminates execution is feature s is not available. +# +# Signature() writes the version, host, and features support in +# the running implementation of Icon. +# +############################################################################ + +procedure Usage(s) + stop("Usage: ",s) +end + +procedure Error(L[]) + push(L,"*** ") + push(L, &errout) + write ! L +end + +procedure ErrorCheck(line,file) + if &errortext == "" then fail # No converted error + write("\nError ",&errornumber," at line ",line, " in file ",file) + write(&errortext) + write("offending value: ",image(&errorvalue)) + return +end + +procedure Feature(s) + if s == &features then return else fail +end + +procedure Requires(s) + if not(Feature(s)) then stop(s," required") +end + +procedure Signature() + write(&version) + write(&host) + every write(&features) +end |