Add into string command

crates/nu-command/Cargo.toml

@@ -22,6 +22,10 @@ unicode-segmentation = "1.8.0"
 glob = "0.3.0"
 thiserror = "1.0.29"
 sysinfo = "0.20.4"
+bigdecimal = { package = "bigdecimal-rs", version = "0.2.1", features = ["serde"] }
+num-bigint = { version="0.3.1", features=["serde"] }
+num-format = { version="0.4.0", features=["with-num-bigint"] }
+num-traits = "0.2.14"
 chrono = { version = "0.4.19", features = ["serde"] }
 chrono-humanize = "0.2.1"
 chrono-tz = "0.6.0"

crates/nu-command/src/conversions/into/mod.rs

@@ -2,8 +2,10 @@ mod binary;
 mod command;
 mod filesize;
 mod int;
+mod string;
 
 pub use self::filesize::SubCommand as IntoFilesize;
 pub use binary::SubCommand as IntoBinary;
 pub use command::Into;
 pub use int::SubCommand as IntoInt;
+pub use string::SubCommand as IntoString;

crates/nu-command/src/conversions/into/string.rs

@@ -0,0 +1,377 @@
+use nu_protocol::Value::Filesize;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
+};
+
+use bigdecimal::{BigDecimal, FromPrimitive};
+
+use nu_engine::CallExt;
+
+use num_bigint::{BigInt, BigUint, ToBigInt};
+use num_format::Locale;
+use num_traits::{Pow, Signed};
+use std::iter;
+// TODO num_format::SystemLocale once platform-specific dependencies are stable (see Cargo.toml)
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "into string"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("into string")
+            // FIXME - need to support column paths
+            // .rest(
+            //     "rest",
+            //     SyntaxShape::ColumnPaths(),
+            //     "column paths to convert to string (for table input)",
+            // )
+            .named(
+                "decimals",
+                SyntaxShape::Int,
+                "decimal digits to which to round",
+                Some('d'),
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Convert value to string"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        string_helper(engine_state, stack, call, input)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "convert decimal to string and round to nearest integer",
+                example: "1.7 | into string -d 0",
+                result: Some(Value::String {
+                    val: "2".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "convert decimal to string",
+                example: "1.7 | into string -d 1",
+                result: Some(Value::String {
+                    val: "1.7".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "convert decimal to string and limit to 2 decimals",
+                example: "1.734 | into string -d 2",
+                result: Some(Value::String {
+                    val: "1.73".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "try to convert decimal to string and provide negative decimal points",
+                example: "1.734 | into string -d -2",
+                result: None,
+                // FIXME
+                // result: Some(Value::Error {
+                //     error: ShellError::UnsupportedInput(
+                //         String::from("Cannot accept negative integers for decimals arguments"),
+                //         Span::unknown(),
+                //     ),
+                // }),
+            },
+            Example {
+                description: "convert decimal to string",
+                example: "4.3 | into string",
+                result: Some(Value::String {
+                    val: "4.3".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "convert string to string",
+                example: "'1234' | into string",
+                result: Some(Value::String {
+                    val: "1234".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "convert boolean to string",
+                example: "$true | into string",
+                result: Some(Value::String {
+                    val: "true".to_string(),
+                    span: Span::unknown(),
+                }),
+            },
+            Example {
+                description: "convert date to string",
+                example: "date now | into string",
+                result: None,
+            },
+            Example {
+                description: "convert filepath to string",
+                example: "ls Cargo.toml | get name | into string",
+                result: None,
+            },
+            Example {
+                description: "convert filesize to string",
+                example: "ls Cargo.toml | get size | into string",
+                result: None,
+            },
+        ]
+    }
+}
+
+fn string_helper(
+    engine_state: &EngineState,
+    stack: &mut Stack,
+    call: &Call,
+    input: PipelineData,
+) -> Result<nu_protocol::PipelineData, ShellError> {
+    let decimals = call.has_flag("decimals");
+    let head = call.head;
+    let decimals_value: Option<i64> = call.get_flag(engine_state, stack, "decimals")?;
+
+    if decimals && decimals_value.is_some() && decimals_value.unwrap().is_negative() {
+        return Err(ShellError::UnsupportedInput(
+            "Cannot accept negative integers for decimals arguments".to_string(),
+            head,
+        ));
+    }
+
+    input.map(
+        move |v| action(v, head, decimals, decimals_value, false),
+        engine_state.ctrlc.clone(),
+    )
+}
+
+pub fn action(
+    input: Value,
+    head: Span,
+    decimals: bool,
+    digits: Option<i64>,
+    group_digits: bool,
+) -> Value {
+    match input {
+        Value::Int { val, span } => {
+            let res = if group_digits {
+                format_int(val) // int.to_formatted_string(*locale)
+            } else {
+                val.to_string()
+            };
+
+            Value::String {
+                val: res,
+                span: head,
+            }
+        }
+        Value::Float { val, span } => {
+            if decimals {
+                let dec = BigDecimal::from_f64(val);
+                let decimal_value = digits.unwrap() as u64;
+                match dec {
+                    Some(x) => Value::String {
+                        val: format_decimal(x, Some(decimal_value), group_digits),
+                        span,
+                    },
+                    None => Value::Error {
+                        error: ShellError::CantConvert(
+                            String::from(format!("cannot convert {}to BigDecimal", val)),
+                            head,
+                        ),
+                    },
+                }
+            } else {
+                Value::String {
+                    val: val.to_string(),
+                    span: head,
+                }
+            }
+        }
+        // We do not seem to have BigInt at the moment as a Value Type
+        // Value::BigInt { val, span } => {
+        //     let res = if group_digits {
+        //         format_bigint(val) // int.to_formatted_string(*locale)
+        //     } else {
+        //         int.to_string()
+        //     };
+
+        //     Value::String {
+        //         val: res,
+        //         span: head,
+        //     }
+        //     .into_pipeline_data()
+        // }
+        Value::Bool { val, span } => Value::String {
+            val: val.to_string(),
+            span: head,
+        },
+
+        Value::Date { val, span } => Value::String {
+            val: val.format("%c").to_string(),
+            span: head,
+        },
+
+        Value::String { val, span } => Value::String { val, span: head },
+
+        // FIXME - we do not have a FilePath type anymore. Do we need to support this?
+        // Value::FilePath(a_filepath) => a_filepath.as_path().display().to_string(),
+        Value::Filesize { val, span } => {
+            // let byte_string = InlineShape::format_bytes(*val, None);
+            // Ok(Value::String {
+            //     val: byte_string.1,
+            //     span,
+            // }
+            Value::String {
+                val: input.into_string(),
+                span: head,
+            }
+        }
+        Value::Nothing { span } => Value::String {
+            val: "nothing".to_string(),
+            span: head,
+        },
+        Value::Record { cols, vals, span } => Value::Error {
+            error: ShellError::UnsupportedInput(
+                "Cannot convert Record into string".to_string(),
+                head,
+            ),
+        },
+
+        _ => Value::Error {
+            error: ShellError::CantConvert(
+                String::from(" into string. Probably this type is not supported yet"),
+                head,
+            ),
+        },
+    }
+}
+fn format_int(int: i64) -> String {
+    int.to_string()
+
+    // TODO once platform-specific dependencies are stable (see Cargo.toml)
+    // #[cfg(windows)]
+    // {
+    //     int.to_formatted_string(&Locale::en)
+    // }
+    // #[cfg(not(windows))]
+    // {
+    //     match SystemLocale::default() {
+    //         Ok(locale) => int.to_formatted_string(&locale),
+    //         Err(_) => int.to_formatted_string(&Locale::en),
+    //     }
+    // }
+}
+
+fn format_bigint(int: &BigInt) -> String {
+    int.to_string()
+
+    // TODO once platform-specific dependencies are stable (see Cargo.toml)
+    // #[cfg(windows)]
+    // {
+    //     int.to_formatted_string(&Locale::en)
+    // }
+    // #[cfg(not(windows))]
+    // {
+    //     match SystemLocale::default() {
+    //         Ok(locale) => int.to_formatted_string(&locale),
+    //         Err(_) => int.to_formatted_string(&Locale::en),
+    //     }
+    // }
+}
+
+fn format_decimal(mut decimal: BigDecimal, digits: Option<u64>, group_digits: bool) -> String {
+    if let Some(n) = digits {
+        decimal = round_decimal(&decimal, n)
+    }
+
+    if decimal.is_integer() && (digits.is_none() || digits == Some(0)) {
+        let int = decimal.as_bigint_and_exponent().0;
+        // .expect("integer BigDecimal should convert to BigInt");
+        return if group_digits {
+            int.to_string()
+        } else {
+            format_bigint(&int)
+        };
+    }
+
+    let (int, exp) = decimal.as_bigint_and_exponent();
+    let factor = BigInt::from(10).pow(BigUint::from(exp as u64)); // exp > 0 for non-int decimal
+    let int_part = &int / &factor;
+    let dec_part = (&int % &factor)
+        .abs()
+        .to_biguint()
+        .expect("BigInt::abs should always produce positive signed BigInt and thus BigUInt")
+        .to_str_radix(10);
+
+    let dec_str = if let Some(n) = digits {
+        dec_part
+            .chars()
+            .chain(iter::repeat('0'))
+            .take(n as usize)
+            .collect()
+    } else {
+        String::from(dec_part.trim_end_matches('0'))
+    };
+
+    let format_default_loc = |int_part: BigInt| {
+        let loc = Locale::en;
+        //TODO: when num_format is available for recent bigint, replace this with the locale-based format
+        let (int_str, sep) = (int_part.to_string(), String::from(loc.decimal()));
+
+        format!("{}{}{}", int_str, sep, dec_str)
+    };
+
+    format_default_loc(int_part)
+
+    // TODO once platform-specific dependencies are stable (see Cargo.toml)
+    // #[cfg(windows)]
+    // {
+    //     format_default_loc(int_part)
+    // }
+    // #[cfg(not(windows))]
+    // {
+    //     match SystemLocale::default() {
+    //         Ok(sys_loc) => {
+    //             let int_str = int_part.to_formatted_string(&sys_loc);
+    //             let sep = String::from(sys_loc.decimal());
+    //             format!("{}{}{}", int_str, sep, dec_str)
+    //         }
+    //         Err(_) => format_default_loc(int_part),
+    //     }
+    // }
+}
+
+fn round_decimal(decimal: &BigDecimal, mut digits: u64) -> BigDecimal {
+    let mut mag = decimal.clone();
+    while mag >= BigDecimal::from(1) {
+        mag = mag / 10;
+        digits += 1;
+    }
+
+    decimal.with_prec(digits)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/default_context.rs

@@ -53,6 +53,7 @@ pub fn create_default_context() -> EngineState {
             IntoBinary,
             IntoFilesize,
             IntoInt,
+            IntoString,
             Last,
             Length,
             Let,