57290d63fd
* cfg.mk: Disable checks where needed (e.g., we do want to check the behavior with tabs). (sc_at_parser_check): Remove. Unfortunately sincea11c144609we no longer use the './' prefix to run programs in the current directory. That was so that we could run Java programs like the other, although they are no run with the `./` prefix (see967a59d2c0). As a consequence this sc check no longer makes sense. However, since now AT_PARSER_CHECK passes the `./` prefix itself, this sc-check was superfluous. * examples/c/reccalc/scan.l: Use memcpy, not strncpy. * src/ielr.c, src/reader.c: Obfuscate "lr(0)" so that the sc-check for "space before paren" does not fire. * tests/diagnostics.at: Avoid space-tab, use tab-tab.
Examples in C
This directory contains simple examples of Bison grammar files in C.
Some of them come from the documentation, which should be installed together with Bison. The URLs are provided for convenience.
rpcalc - Reverse Polish Notation Calculator
The first example is that of a simple double-precision Reverse Polish Notation calculator (a calculator using postfix operators). This example provides a good starting point, since operator precedence is not an issue.
Extracted from the documentation: "Reverse Polish Notation Calculator" https://www.gnu.org/software/bison/manual/html_node/RPN-Calc.html
calc - Simple Calculator
This example is slightly more complex than rpcalc: it features infix
operators (1 + 2, instead of 1 2 + in rpcalc), but it does so using a
unambiguous grammar of the arithmetic instead of using precedence
directives (%left, etc.).
mfcalc - Multi-Function Calculator
A more complete C example: a multi-function calculator. More complex than the previous example. Using precedence directives to support infix operators.
Extracted from the documentation: "Multi-Function Calculator: mfcalc". https://www.gnu.org/software/bison/manual/html_node/Multi_002dfunction-Calc.html
lexcalc - calculator with Flex and Bison
The calculator, redux. This time using a scanner generated by Flex.
reccalc - recursive calculator with Flex and Bison
The example builds on top of the previous one to provide a reentrant parser.
Such parsers can be called concurrently in different threads, or even
recursively. To demonstrate this feature, expressions in parentheses are
tokenized as strings, and then recursively parsed from the parser. So
(((1)+(2))*((3)+(4))) uses eight parsers, with a depth of four.