diff options
Diffstat (limited to 'Functions/Misc')
| -rw-r--r-- | Functions/Misc/zcalc | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/Functions/Misc/zcalc b/Functions/Misc/zcalc new file mode 100644 index 000000000..80a031a8b --- /dev/null +++ b/Functions/Misc/zcalc @@ -0,0 +1,142 @@ +#!/usr/local/bin/zsh -i +# +# Zsh calculator. Understands most ordinary arithmetic expressions. +# Line editing and history are available. A blank line or `q' quits. +# +# Runs as a script or a function. If used as a function, the history +# is remembered for reuse in a later call (and also currently in the +# shell's own history). There are various problems using this as a +# script, so a function is recommended. +# +# The prompt shows a number for the current line. The corresponding +# result can be referred to with $<line-no>, e.g. +# 1> 32 + 10 +# 42 +# 2> $1 ** 2 +# 1764 +# The set of remembered numbers is primed with anything given on the +# command line. For example, +# zcalc '2 * 16' +# 1> 32 # printed by function +# 2> $1 + 2 # typed by user +# 34 +# 3> +# Here, 32 is stored as $1. This works in the obvious way for any +# number of arguments. +# +# If the mathfunc library is available, probably understands most system +# mathematical functions. The left parenthesis must be adjacent to the +# end of the function name, to distinguish from shell parameters +# (translation: to prevent the maintainers from having to write proper +# lookahead parsing). For example, +# 1> sqrt(2) +# 1.4142135623730951 +# is right, but `sqrt (2)' will give you an error. +# +# You can do things with parameters like +# 1> pi = 4.0 * atan(1) +# too. These go into global parameters, so be careful. You can declare +# local variables, however: +# 1> local pi +# but note this can't appear on the same line as a calculation. Don't +# use the variables listed in the `local' and `integer' lines below +# (translation: I can't be bothered to provide a sandbox). +# +# Some constants are already available: (case sensitive as always): +# PI pi, i.e. 3.1415926545897931 +# E e, i.e. 2.7182818284590455 +# +# You can also change the output base. +# 1> [#16] +# 1> +# Changes the default output to hexadecimal with numbers preceded by `16#'. +# Note the line isn't remembered. +# 2> [##16] +# 2> +# Change the default output base to hexadecimal with no prefix. +# 3> [#] +# Reset the default output base. +# +# This is based on the builtin feature that you can change the output base +# of a given expression. For example, +# 1> [##16] 32 + 20 / 2 +# 2A +# 2> +# prints the result of the calculation in hexadecimal. +# +# You can't change the default input base, but the shell allows any small +# integer as a base: +# 1> 2#1111 +# 15 +# 2> [##13] 13#6 * 13#9 +# 42 +# and the standard C-like notation with a leading 0x for hexadecimal is +# also understood. However, leading 0 for octal is not understood --- it's +# too confusing in a calculator. Use 8#777 etc. +# +# +# To do: +# - separate zcalc history from shell history using arrays --- or allow +# zsh to switch internally to and from array-based history. +# - allow setting number of decimal places for display, scientific notation, +# etc. + +emulate -L zsh +setopt extendedglob + +local line latest base defbase match mbegin mend +integer num + +zmodload -i zsh/mathfunc 2>/dev/null + +# Supply some constants. +float PI E +(( PI = 4 * atan(1), E = exp(1) )) + +for (( num = 1; num <= $#; num++ )); do + # Make sure all arguments have been evaluated. + # The `$' before the second argv forces string rather than numeric + # substitution. + (( argv[$num] = $argv[$num] )) + print "$num> $argv[$num]" +done + +while vared -chp "$num> " line; do + [[ -z $line ]] && break + # special cases + # Set default base if `[#16]' or `[##16]' etc. on its own. + # Unset it if `[#]' or `[##]'. + if [[ $line = (#b)[[:blank:]]#('[#'(\#|)(<->|)']')[[:blank:]]#(*) ]]; then + if [[ -z $match[4] ]]; then + if [[ -z $match[3] ]]; then + defbase= + else + defbase=$match[1] + fi + print -s -- $line + line= + continue + else + base= + fi + else + base=$defbase + fi + # Exit if `q' on its own. + [[ $line = [[:blank:]]#q[[:blank:]]# ]] && return 0 + + print -s -- $line + if [[ $line = [[:blank:]]#local([[:blank:]]##*|) ]]; then + eval $line + else + # Latest value is stored as a string, because it might be floating + # point or integer --- we don't know till after the evaluation, and + # arrays always store scalars anyway. + eval "latest=\$(( $base $line ))" + argv[num++]=$latest + print -- $latest + fi + line= +done + +return 0 |