1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
#!/usr/local/bin/tclsh8.0
#
# Project : tcLex examples
# File : pascal.tcl
# Language : Tcl, with tcLex
# Version : 0.1
# Dates : 10/11/1998
# Author : Neil Walker
#
# "scanner for a toy Pascal-like langauge"
#
# To run this program:
# ./pascal.tcl textfile
#
package require tcLex 1.1
lexer pascal -longest -nocase {
{} {[0-9]+} {integer} {puts "An integer: $integer"}
{} {[0-9]+\.[0-9]*} {float} {puts "A float: $float"}
{} {if|then|begin|end|procedure|function} {keyword} {puts "A keyword: $keyword"}
{} {[a-z][a-z0-9]*} {id} {puts "An identifier: $id"}
{} {\+|-|\*|/} {op} {puts "An operator: $op"}
{} "\{[^\}\n]*\}" {} {# eat up one-line comments}
{} "[ \t\n]+" {} {# eat up whitespace}
{} {.} {c} {puts "Unrecognized character: $c"}
}
if {$argc > 0} {
pascal eval [read [open [lindex $argv 0] r]]
} else {
pascal eval [read stdin]
}
|
